WO2024148082A1

WO2024148082A1 - Linear telechelic diene copolymers and their use in tire components

Info

Publication number: WO2024148082A1
Application number: PCT/US2024/010172
Authority: WO
Inventors: Vrushali BHAGAT; Rita E. COOK; Sem Raj TAMANG; Shammi AHMED
Original assignee: Bridgestone Corporation
Priority date: 2023-01-03
Filing date: 2024-01-03
Publication date: 2024-07-11

Abstract

A method for preparing a linear telechelic diene copolymer, the method comprising (i) preparing a dilithium initiator by reacting dialkenyl compound with an alkyl lithium compound; (ii) introducing the dilithium initiator, diene monomer, vinyl aromatic monomer, and a randomizer to form a polymerization mixture; (iii) allowing the diene monomer and vinyl aromatic monomer to polymerize and form a polymer having first and second reactive ends; and (iv) functionalizing both the first and second reactive ends of the polymer by reacting the first and second reactive ends with first and second functionalizing agents to thereby form a linear telechelic diene copolymer.

Description

^{LINEAR TELECHELIC DIENE COPOLYMERS AND THEIR USE IN TIRE COMPONENTS} FIELD OF THE INVENTION ^{[0001] Embodiments of the present invention provide linear telechelic diene copolymers,} _{as well as their use of the branched polymers in the preparation of tire components.} BACKGROUND OF THE INVENTION ^{[0002] Polydienes, such as poly(butadiene) and diene copolymers, such as poly(styrene-} ^{co-butadiene) are often made by employing anionic polymerization techniques whereby} ^{diene monomer, optionally together with copolymerizable monomer such as vinyl} ^{aromatics, are polymerized using an anionic initiator. The use of anionic polymerization} ^{techniques leads to several advantages including the ability to control molecular weight,} ^{prepare relatively linear polymer chains, and functionalize the polymer chain through a} _{chain termination reaction. Useful anionic initiators may include, for example, alkyl lithium} _{compounds such as n-butyl lithium. Multi-functional initiators can be formed by reacting,} _{for example, an alkyl lithium compound with a dialkenyl compound such as} _{diisopropenylbenzene. Polymers prepared by using multi-functional initiators have} _{multiple reactive chain ends, which provides the ability to functionalize both ends of a} _{polymer chain to form a telechelic polymer.} SUMMARY OF THE INVENTION ^{[0003] One or more embodiments of the present invention provide a method for} ^{preparing a linear telechelic diene copolymer, the method comprising (i) preparing a} ^{dilithium initiator by reacting dialkenyl compound with an alkyl lithium compound; (ii)} ^{introducing the dilithium initiator, diene monomer, vinyl aromatic monomer, and a} _{randomizer to form a polymerization mixture; (iii) allowing the diene monomer and vinyl} _{aromatic monomer to polymerize and form a polymer having first and second reactive ends;} _{and (iv) functionalizing both the first and second reactive ends of the polymer by reacting} _{the first and second reactive ends with first and second functionalizing agents to thereby} _{form a linear telechelic diene copolymer.} ^{[0004] Other embodiments of the present invention provide a vulcanizable composition} _{of matter including a linear telechelic polymer.} ^{[0005] Still other embodiments of the present invention provide a vulcanizate prepared} _{by vulcanizing a vulcanizable composition of matter including a linear telechelic polymer .} ^{[0006] Yet other embodiments of the present invention provide a tire component} _{prepared from a vulcanizable composition including a linear telechelic polymer.} ^{[0007] Still yet other embodiments of the present invention provide a tire tread prepared} _{from a vulcanizable composition including a linear telechelic polymer.} ^{[0008] Other embodiments of the present invention provide a vulcanizable composition} ^{comprising (i) a linear telechelic diene copolymer prepared by preparing a dilithium initiator} ^{by reacting dialkenyl compound with an alkyl lithium compound; introducing the dilithium} ^{initiator, diene monomer, vinyl aromatic monomer, and a randomizer to form a} _{polymerization mixture; allowing the diene monomer and vinyl aromatic monomer to} _{polymerize and form a polymer having first and second reactive ends; and functionalizing} _{both the first and second reactive ends of the polymer by reacting the first and second} _{reactive ends with first and second functionalizing agents to thereby form a linear telechelic} _{diene copolymer; (ii) silica; and (iii) a curative.} ^{[0009] Still other embodiments of the present invention provide a method for forming a} ^{vulcanizable composition, the method comprising (i) providing a linear telechelic diene} ^{copolymer prepared by preparing a dilithium initiator by reacting dialkenyl compound with} ^{an alkyl lithium compound; introducing the dilithium initiator, diene monomer, vinyl} ^{aromatic monomer, and a randomizer to form a polymerization mixture; allowing the diene} _{monomer and vinyl aromatic monomer to polymerize and form a polymer having first and} _{second reactive ends; and functionalizing both the first and second reactive ends of the} _{polymer by reacting the first and second reactive ends with first and second functionalizing} _{agents to thereby form a linear telechelic diene copolymer; (ii) providing silica; (iii)} _{providing a curative; and mixing the linear telechelic diene copolymer, silica, and curative to} _{form the vulcanizable composition.} DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS ^{[0010] Embodiments of the invention are based, at least in part, on the discovery of linear} ^{telechelic diene copolymers prepared by polymerizing monomer with a dilithium initiator.} ^{According to embodiments of the invention, the dilithium initiator is prepared by reacting} ^{an alkyl lithium compound with a dialkenyl compound and allowing the initiator to age.} _{Initiator aging in the presence of a Lewis base has also been found to contribute to improved} _{polymer properties. Inasmuch as the polymers are prepared by anionic polymerization} _{techniques, the use of a dilithium initiator advantageously leads to multiple polymer live} _{ends (i.e. reactive ends), which allows for preparing telechelic diene copolymers.} PREPARATION OF LINEAR TELECHELIC COPOLYMERS ^{[0011] In one or more embodiments, the linear telechelic diene copolymers, which may} ^{be referred to as difunctional copolymers or difunctionalized polymers or simply} ^{functionalized polymers, are prepared by polymerizing diene monomer together with vinyl} _{aromatic monomer, with a dilithium initiator. The dilithium initiator is prepared by reacting} _{an alkyl lithium compound with a dialkenyl compound. In one or more embodiments, the} _{dilithium initiator is aged in an appropriate solvent in the presence of a Lewis base prior to} _{its use in polymerization.} INITIATOR PREPARATION AND AGING ^{[0012] As indicated above, the dilithium initiator is prepared by combining a dialkenyl} ^{compound with an alkyl lithium compound within a solvent that forms a reaction mixture in} _{which the reactants and product are at least partially soluble. The initiator is then aged in} _{an appropriate solvent in the presence of a Lewis base.} ^{[0013] In one or more embodiments, the dialkenyl compound is a 1,3-dialkenylbenzene} ^{compound such as 1,3-diisopropenylbenzene. In one or more embodiments, the alkyl} _{lithium compound is a butyl lithium compound such as n-butyl lithium, t-butyl lithium,} _{and/or sec-butyl lithium. In particular embodiments, sec-butyl lithium is employed.} ^{[0014] The Lewis base may include any Lewis base that does not include an active} ^{hydrogen atom, where the presence of an active hydrogen atom is determined by the} _{Zerewitinoff test. Exemplary Lewis bases include oxolanyl propanes such as 2,2-bis(2-} _{oxolanyl)propane (also known as 2,2-ditetrahydrofurylpropane), meso-2,2-} ^{diterahydrofurylpropane, DL-2,2,-ditetrahdydrofurlypropane,} ^{tetramethylethylenediamine, and mixtures thereof, as well as trialkyl amines such as triethyl} _{amine. In particular embodiments, triethyl amine is employed.} ^{[0015] The amount of alkyl lithium compound reacted with the dialkenyl compound may} ^{be quantified based upon the molar ratio of lithium to alkenyl groups; that is, equivalents of} ^{lithium associated with the alkyl lithium compound (i.e. mole of Li) relative to the} ^{equivalents of alkenyl groups within the dialkenyl compound (e.g. equivalents of isopropenyl} ^{groups within 1,3-diisopropenylbenzene. In one or more embodiments, the molar ratio of} _{moles of Li associated with the alkyl lithium to equivalents of alkenyl groups associated with} _{the dialkenyl compound may be from about 1.95:1 to about 2.05:1, in other embodiments} _{from about 1.97:1 to about 2.03:1, and in other embodiments from about 1.99:1 to about} _{2.01:1. Where sec-butyl lithium is reacted with 1,3-diisopropenylbenzene, 2.00 moles of sec-} _{butyl lithium may be reacted with each mole of 1,3-diisopropenylbenzene.} ^{[0016] The synthesis of the initiator takes place within a solvent in which the reactants} ^{and the product is at least partially soluble. Useful solvents include, but are not limited to,} ^{hydrocarbons with a low or relatively low boiling point such as aromatic hydrocarbons,} ^{aliphatic hydrocarbons, and cycloaliphatic hydrocarbons. Non-limiting examples of} ^{aromatic hydrocarbons include benzene, toluene, xylenes, ethylbenzene, diethylbenzene,} _{and mesitylene. Non-limiting examples of aliphatic hydrocarbons include n-pentane, n-} _{hexane, n-heptane, n-octane, n-nonane, n-decane, isopentane, isohexanes, isopentanes,} _{isooctanes, 2,2-dimethylbutane, petroleum ether, kerosene, and petroleum spirits. And,} _{non-limiting examples of cycloaliphatic hydrocarbons include cyclopentane, cyclohexane,} _{methylcyclopentane, and methylcyclohexane. Mixtures of the above hydrocarbons may also} _{be used.} ^{[0017] As indicated above, the dilithium initiator formed by the foregoing reaction is} ^{aged within an appropriate solvent (e.g. within the reaction medium) in the presence of a} ^{Lewis base. In one or more embodiments, the Lewis base is present at the introduction of} _{the reactants to the reaction mixture. In other embodiments, the Lewis base is introduced} _{after synthesis of the dilithium initiator, and aging takes place after introduction of the Lewis} _base. ^{[0018] The amount of Lewis base introduced to the reaction mixture may be quantified} ^{based upon the moles of Lewis base (e.g.2,2-ditetrahydrofurylpropane) relative to the moles} ^{of lithium associated with the alkyl lithium compound (i.e. molar ratio of moles Lewis base} _{to moles of lithium). In one or more embodiments, the molar ratio of moles of Lewis base} _{introduced to the reaction medium to moles of lithium introduced with the alkyl lithium} _{compound is from about 0.05:1 to about 1:1, in other embodiments from about 0.1:1 to about} _{0.6:1, and in other embodiments from about 0.2:1 to about 0.45:1.} ^{[0019] In one or more embodiments, aging of the initiator takes place under an inert} ^{atmosphere at atmospheric conditions at a temperature of from about 0 to about 150 ℃, in} ^{other embodiments from about 25 to about 100 ℃, and in other embodiments from about} ^{35 to about 60 ℃. In one or more embodiments, the initiator is aged for greater than 15} ^{minutes, in other embodiments greater than 20 minutes, in other embodiments greater than} ^{25 minutes, and in other embodiments greater than 30 minutes before introducing the} ^{initiator to the monomer to be polymerized. In one or more embodiments, the initiator is} ^{aged for from about 15 minutes to about 4 hours, in other embodiments from about 20} _{minutes to about 3 hours, and in other embodiments from about 30 minutes to about 2 hours} _{before introducing the initiator to the monomer to be polymerized. The appropriate aging} _{time is temperature dependent; that is, the time necessary to age the initiator decreases with} _{increased temperature. Likewise, the maximum amount of aging decreases with} _{temperature. It should also be appreciated that the temperature dependence of the aging} _{process may allow for longer storage times at cold temperatures. For example, it is believed} _{that the initiator (i.e. the combination of the dialkenyl compound and the alkyl lithium) can} _{be stored for periods of, for example, 24 hours at temperatures below 0 ℃.} POLYMERIZATION REACTION ^{[0020] The dilithium initiator as prepared above, and optionally aged, is combined with} ^{monomer to be polymerized, within an appropriate a solvent to form a polymerization} _{mixture in which the monomer and resulting polymer are at least partially soluble. In one} _{or more embodiments, the initiator is also at least partially soluble within the polymerization} _mixture. ^{[0021] Generally speaking, the polymerization of monomer by the initiator proceeds by} ^{anionic polymerization techniques. The preparation of polymer by employing anionic} ^{polymerization techniques is generally known. The key mechanistic features of anionic} ^{polymerization have been described in books (e.g., Hsieh, H. L.; Quirk, R. P. Anionic} ^{Polymerization: Principles and Practical Applications; Marcel Dekker: New York, 1996) and} ^{review articles (e.g., Hadjichristidis, N.; Pitsikalis, M.; Pispas, S.; Iatrou, H.; Chem. Rev. 2001,} ^{101(12), 3747-3792). Anionic initiators may advantageously produce polymer having} _{reactive chain ends (e.g., living polymers) that, prior to quenching, are capable of reacting} _{with additional monomers for further chain growth or reacting with certain functionalizing} _{agents to give functionalized polymers. The polymers having reactive polymer chain ends} _{may simply be referred to as reactive polymers. As those skilled in the art appreciate, these} _{reactive polymers include a reactive chain end, which is believed to be ionic, at which a} _{reaction between a functionalizing agent and the reactive chain end of the polymer can take} _{place, which thereby imparts a functionality or functional group to the polymer chain end,} _{or which may couple multiple polymers together.} ^{[0022] The polymerization mixture can be formed by introducing the various} ^{constituents in any order. For example, in one or more embodiments, the monomer, and} _{solvent can first be combined, and then the aged initiator can be introduced to the mixture.} MONOMER TO BE POLYMERIZED ^{[0023] As indicated above, the monomer to be polymerized includes conjugated diene} ^{monomer and vinyl-substituted aromatic monomer, which may also be referred to as vinyl} ^{aromatic monomer or comonomer. Examples of conjugated diene monomer include} ^{1,3-butadiene, isoprene, 1,3-pentadiene, 1,3-hexadiene, 2,3-dimethyl-1,3-butadiene,} _{2-ethyl-1,3-butadiene, 2-methyl-1,3-pentadiene, 3-methyl-1,3-pentadiene, 4-methyl-} _{1,3-pentadiene, and 2,4-hexadiene. Mixtures of two or more conjugated dienes may also be} _{utilized in copolymerization. Examples of vinyl-substituted aromatic monomer include} _{styrene, p-methylstyrene, α-methylstyrene, and vinylnaphthalene.} ^{[0024] The amount of the initiator to be employed may depend on the interplay of} ^{various factors such as the type of initiator employed, the purity of the ingredients, the} _{polymerization temperature, the polymerization rate and conversion desired, the molecular} ^{weight desired, and many other factors. In one or more embodiments, the amount of} ^{initiator employed may be expressed as the mmols of initiator per weight of monomer. In} ^{one or more embodiments, the amount of initiator introduced to the polymerization mixture} _{is from about 0.1 to about 100 mmol, or in other embodiments from about 0.2 to about 50} _{mmol, or in other embodiments from about 0.3 to about 15 mmol of the initiator per 100} _{gram of monomer within the polymerization mixture (i.e. monomer to be polymerized).} SOLVENT FOR POLYMERIZATION MIXTURE ^{[0025] In one or more embodiments, suitable solvents include those organic compounds} ^{that will not undergo polymerization or incorporation into propagating polymer chains} ^{during the polymerization of monomer in the presence of catalyst. In one or more} ^{embodiments, these organic species are liquid at ambient temperature and pressure. In one} ^{or more embodiments, these organic solvents are inert to the catalyst. Exemplary organic} _{solvents include hydrocarbons with a low or relatively low boiling point such as aromatic} _{hydrocarbons, aliphatic hydrocarbons, and cycloaliphatic hydrocarbons. Non-limiting} _{examples of aromatic hydrocarbons include benzene, toluene, xylenes, ethylbenzene,} _{diethylbenzene, and mesitylene. Non-limiting examples of aliphatic hydrocarbons include} ^{n-pentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane, isopentane, isohexanes,} ^{isopentanes, isooctanes, 2,2-dimethylbutane, petroleum ether, kerosene, and petroleum} ^{spirits. And, non-limiting examples of cycloaliphatic hydrocarbons include cyclopentane,} ^{cyclohexane, methylcyclopentane, and methylcyclohexane. Mixtures of the above} ^{hydrocarbons may also be used. The low-boiling hydrocarbon solvents are typically} _{separated from the polymer upon completion of the polymerization. Other examples of} _{organic solvents include high-boiling hydrocarbons of high molecular weights, such as} _{paraffinic oil, aromatic oil, or other hydrocarbon oils that are commonly used to oil-extend} _{polymers. Since these hydrocarbons are non-volatile, they typically do not require} _{separation and remain incorporated in the polymer.} MODIFIER ^{[0026] The polymerization reaction may be conducted in the presence of a modifier,} ^{which may also be referred to as a polar coordinator or a vinyl modifier. As those skilled in} _{the art appreciate, these compounds may serve multiple roles in the polymerization. For} ^{example, they can assist in randomizing comonomer throughout the polymer chain; they} ^{may also modify the vinyl content of the mer units deriving from dienes. Compounds useful} ^{as modifiers include those having an oxygen or nitrogen heteroatom and a non-bonded pair} ^{of electrons. Examples include linear and cyclic oligomeric oxolanyl alkanes; dialkyl ethers} ^{of mono and oligo alkylene glycols (also known as glyme ethers); “crown” ethers; tertiary} ^{amines; linear THF oligomers; and the like. Linear and cyclic oligomeric oxolanyl alkanes} ^{are described in U.S. Patent Nos. 4,429,091 and 9,868,795, which are incorporated herein by} ^{reference. Specific examples of compounds useful as randomizers include 2,2-bis(2-} _{oxolanyl)propane (also known as 2,2-ditetrahydrofurylpropane), meso-2,2-} _{diterahydrofurylpropane, DL-2,2,-ditetrahdydrofurlypropane, and mixtures thereof, 1,2-} _{dimethoxyethane, N,N,N’,N’-tetramethylethylenediamine (TMEDA), tetrahydrofuran (THF),} _{1,2-dipiperidylethane, dipiperidylmethane, hexamethylphosphoramide, N-N'-} _{dimethylpiperazine, diazabicyclooctane, dimethyl ether, diethyl ether, tri-n-butylamine , and} _{mixtures thereof. In other embodiments, potassium alkoxides can be used to randomize the} _{styrene distribution. In one or more embodiments, a randomizer other than a potassium} _{alkoxide is employed. In other embodiments, potassium alkoxide is the only randomizer} _{present within the polymerization mixture.} ^{[0027] The amount of randomizer to be employed may depend on various factors such} ^{as the desired microstructure of the polymer, the ratio of monomer to comonomer, the} _{polymerization temperature, as well as the nature of the specific randomizer employed.} POLYMERIZATION CONDITIONS AND TECHNIQUES ^{[0028] The anionic initiator and the randomizer can be introduced to the polymerization} ^{system by various methods. In one or more embodiments, the anionic initiator and the} _{randomizer may be added separately to the monomer to be polymerized in either a stepwise} _{or simultaneous manner.} ^{[0029] As indicated above, polymerization of conjugated diene monomer and vinyl} ^{aromatic monomer, in the presence of an effective amount of initiator, produces a reactive} ^{polymer. The introduction of the initiator, the conjugated diene monomer, the comonomer,} _{and the solvent forms a polymerization mixture in which the reactive polymer is formed.} _{Polymerization within a solvent produces a polymerization mixture in which the polymer} ^{product is dissolved or suspended in the solvent. This polymerization mixture may be} _{referred to as a polymer cement.} ^{[0030] In one or more embodiments, the polymerization may be conducted in any} ^{conventional polymerization vessel known in the art. For example, the polymerization can} ^{be conducted in a conventional stirred-tank reactor. In one or more embodiments, all of the} ^{ingredients used for the polymerization can be combined within a single vessel (e.g., a} ^{conventional stirred-tank reactor), and all steps of the polymerization process can be} _{conducted within this vessel. In other embodiments, two or more of the ingredients can be} _{pre-combined in one vessel and then transferred to another vessel where the polymerization} _{of monomer (or at least a major portion thereof) may be conducted. Because various} _{embodiments of the present invention include the use of multiple reactors or reaction zones,} _{the vessel (e.g., tank reactor) in which the polymerization is conducted may be referred to as} _{a first vessel or first reaction zone.} ^{[0031] The polymerization can be carried out as a batch process, a continuous process,} ^{or a semi-continuous process. In the semi-continuous process, the monomer is} ^{intermittently charged as needed to replace that monomer already polymerized. In one or} ^{more embodiments, the heat of polymerization may be removed by external cooling by a} ^{thermally controlled reactor jacket, internal cooling by evaporation and condensation of the} ^{monomer through the use of a reflux condenser connected to the reactor, or a combination} _{of the two methods. Also, conditions may be controlled to conduct the polymerization under} _{a pressure of from about 0.1 atmospheres to 50 atmospheres, in other embodiments from} _{about 0.5 atmosphere to about 20 atmospheres, and in other embodiments from about 1} _{atmosphere to about 10 atmospheres. In one or more embodiments, the pressures at which} _{the polymerization may be carried out include those that ensure that the majority of the} _{monomer is in the liquid phase. In these or other embodiments, the polymerization mixture} _{may be maintained under anaerobic conditions.} ^{[0032] In one or more embodiments, the conditions under which the polymerization} ^{proceeds may be controlled to maintain the peak polymerization temperature of the} _{polymerization mixture at greater than 30 °C, in other embodiments greater than 50 °C, and} _{in other embodiments greater than 70 °C. In these or other embodiments, the conditions} ^{under which the polymerization proceeds may be controlled to maintain the peak} ^{polymerization temperature of the polymerization mixture at less than 120 °C, in other} ^{embodiments less than 110 °C, and in other embodiments less than 100 °C. In one or more} _{embodiments, the conditions under which the polymerization proceeds may be controlled} _{to maintain the temperature of the polymerization mixture within a range from about -10 °C} _{to about 200 °C, in other embodiments from about 0 °C to about 150 °C, and in other} _{embodiments from about 20 °C to about 110 °C.} PRE-FUNCTIONALIZATION POLYMER CHARACTERISTICS ^{[0033] Prior to functionalization, which is further described below, the linear, reactive} ^{polymers may be characterized by their molecular weight, which may include number} ^{average molecular weight (Mn), weight average molecular weight (Mw), and peak molecular} ^{weight (Mp). As those skilled in the art will appreciate, molecular weight can be determined,} ^{for example, by using gel permeation chromatography (GPC) together with an UV} ^{absorption, differential refractometer (DRI), refractive index (RI), infrared (IR) absorption} _{detector and by employing appropriate calibration standards and THF as a solvent. For} _{purposes of this specification, GPC measurements employ polystyrene standards and} _{polystyrene Mark Houwink constants unless otherwise specified. For purposes of this} _{specification, prior to functionalization, the polymer may be referred to as the base polymer,} _{and the pre-functionalized characteristics of the polymer may be referred to as the} _{characteristics of the base polymer.} ^{[0034] In one or more embodiments, the pre-functionalized polymers have an Mp, which} ^{may also be referred to as the base Mp, of greater than 160 kg/mol, in other embodiments} ^{greater than 170 kg/mol, and in other embodiments greater than 180 kg/mol. In these or} ^{other embodiments, the pre-functionalized polymers have a base Mp of less 280 kg/mol, in} _{other embodiments less than 260 kg/mol, and in other embodiments less than 250 kg/mol.} _{In one or more embodiments, the pre-functionalized polymers have a base Mp of from about} _{160 to about 280 kg/mol, in other embodiments from about 170 to about 260 kg/mol, and} _{in other embodiments from about 180 to about 250 kg/mol.} ^{[0035] In one or more embodiments, the pre-functionalized polymers have an Mn, which} _{may also be referred to as the base Mn, of greater than 130 kg/mol, in other embodiments} ^{greater than 140 kg/mol, and in other embodiments greater than 150 kg/mol. In these or} ^{other embodiments, the pre-functionalized polymers have a base Mn of less 300 kg/mol, in} ^{other embodiments less than 280 kg/mol, and in other embodiments less than 260 kg/mol.} _{In one or more embodiments, the pre-functionalized polymers have a base Mn of from about} _{130 to about 300 kg/mol, in other embodiments from about 140 to about 280 kg/mol, and} _{in other embodiments from about 150 to about 260 kg/mol.} ^{[0036] In one or more embodiments, the pre-functionalized polymers have an Mw, which} ^{may also be referred to as the base Mw, of greater than 180 kg/mol, in other embodiments} ^{greater than 190 kg/mol, and in other embodiments greater than 200 kg/mol. In these or} ^{other embodiments, the pre-functionalized polymers have a base Mw of less 500 kg/mol, in} _{other embodiments less than 450 kg/mol, and in other embodiments less than 400 kg/mol.} _{In one or more embodiments, the pre-functionalized polymers have a base Mw of from about} _{180 to about 500 kg/mol, in other embodiments from about 190 to about 450 kg/mol, and} _{in other embodiments from about 200 to about 400 kg/mol.} ^{[0037] In one or more embodiments, the base polymer is monomodal. In these or other} ^{embodiments, the base polymer may be characterized by a polydispersity, which may also} _{be referred to as a molecular weight distribution (Mw/Mn) of less than of less than 3, in other} _{embodiments less than 2.5, in other embodiments less than 2.0, and in other embodiments} _{less than 1.8.} ^{[0038] The pre-functionalized polymers produced according to aspects of the present} ^{invention may be characterized by vinyl content, which may be described as the number of} ^{unsaturations in the 1,2-microstructure relative to the total unsaturations within the} ^{polymer chain. As the skilled person will appreciate, vinyl content can be determined by} ^{NMR analysis at 400 MHz using CDCl3 as a solvent. In one or more embodiments, the pre-} _{functionalized polymers include greater than 5%, in other embodiments greater than 8%, in} _{other embodiments greater than 10%, in other embodiments greater than 20%, and in other} _{embodiments greater than 35% vinyl. In these or other embodiments, the pre-} _{functionalized polymers include less than 80%, in other embodiments less than 60%, and in} _{other embodiments less than 46%. In one or more embodiments, the pre-functionalized} ^{polymers include from about 5% to about 80%, in other embodiments from about 8% to} _{about 60%, and in other embodiments from about 20% to about 46% vinyl.} ^{[0039] The pre-functionalized polymers produced according to aspects of the present} ^{invention may be characterized by bound styrene content (i.e. the amount of styrene} ^{incorporated in the polymer chains), which refers to the weight percent vinyl aromatic} ^{monomer incorporated into polydiene copolymers. As the skilled person appreciates, bound} ^{styrene can be determined with reference to the relative weight of vinyl monomer included} ^{into the polymerization mixture relative to the diene monomer. Alternatively, bound styrene} ^{can be determined by NMR analysis at 400 MHz using CDCl3 as a solvent. In one or more} _{embodiments, the pre-functionalized polymers include greater than 20 wt %, in other} _{embodiments greater than 25 wt %, and in other embodiments greater than 30 wt % bound} _{styrene. In these or other embodiments, the pre-functionalized polymers include less than} _{60 wt %, in other embodiments less than 55 wt %, and in other embodiments less than 50} _{wt % bound styrene. In one or more embodiments, the pre-functionalized polymers include} _{from about 20 to about 60 wt %, in other embodiments from about 25 to about 55 wt %, and} _{in other embodiments from about 30 to about 50 wt % bound styrene.} ^{[0040] The pre-functionalized polymers produced according to aspects of the present} ^{invention may be characterized by T80, which is determined according to ASTM D 1646-19A} ^{by using a Mooney viscometer (e.g. Agilent Technologies) with a large rotor at 100 °C with a} _{4 minute run time after 1 minute of preheating (i.e. ML 1+4 @ 100 °C). In one or more} _{embodiments, the pre-functionalized polymers have a T80 of less than 2 seconds, in other} _{embodiments less than 1.8 seconds, in other embodiments less than 1.6 seconds, and in other} _{embodiments less than 1.4 seconds.} POLYMER FUNCTIONALIZATION ^{[0041] The polymer produced by the polymerization of this invention (i.e. which} ^{proceeds by anionic polymerization techniques) includes reactive ends (i.e. the growing} ^{ends) that are capable of being modified, which may also be referred to as functionalized, to} _{provide functionalized polymers having a functional group at both ends of a linear polymer,} _{which may be referred to as a telechelic polymer. That is, the reactive ends of the polymer} _{are modified, which may also be referred to as functionalized, by introducing a} ^{functionalizing agent to the polymerization mixture. It is believed that the polymer chain} ^{ends react with the functionalizing agent (which may also be referred to as a modifying} ^{agent) to provide a residue of the functionalizing agent at the end of the polymer chain.} ^{Accordingly, the reaction between the polymer and the functionalizing agents produces a} ^{polymer composition wherein both ends of a linear polymer include a terminal group} ^{deriving from the functionalizing agent. It should be appreciated that the reaction between} ^{the functionalizing agent and the reactive ends of the polymer can also result in polymer} ^{coupling of two or more polymer chains. In either event, the polymers bearing a chain-end} ^{functional group or polymers coupled with the residue of the functionalizing agent will both} _{be referred to as modified or functionalized branched polymers unless otherwise} _{designated. It should also be appreciated that the respective functionalizing agents that} _{react with the respective reactive ends of the polymer may be of the same or different type} _{of functionalizing agent; i.e. the may be of the same or different chemical species. The skilled} _{person appreciates that two or more functionalizing agents of different chemical species may} _{be introduced to the reactive polymer and that different chemical species may react at each} _{of the respective ends of the polymer chain. Alternatively, the same chemical species may} _{react at each end. The latter would be the result if one chemical specie of functionalizing} _{agent is introduced to the reactive polymer.} FUNCTIONALIZING AGENTS ^{[0042] Useful functionalizing agents include those functionalizing agents conventionally} ^{employed in the art. In one or more embodiments, the functionalizing agent imparts a} ^{terminal functionality that can be reactive or interactive with other polymer chains} ^{(propagating and/or non-propagating) or with other materials in a rubber compound such} ^{as particulate reinforcing fillers (e.g. carbon black or silica). As described above, enhanced} _{interactivity between a polymer and particulate fillers in rubber compounds improves the} _{mechanical and dynamic properties of resulting vulcanizates. For example, certain} _{functionalizing agents can impart a terminal functionality that includes one or more} _{heteroatoms. In one or more embodiments, the functionalizing agent may produce a} _{functionalized polymer that can be used in rubber compositions from which vulcanizates can} _{be provided, and these vulcanizates can possess high temperature (e.g., 50 °C) hysteresis} ^{losses that are less than those possessed by vulcanizates prepared from similar rubber} ^{compounds that do not include the functionalized polymers. Reductions in high temperature} _{hysteresis loss can be at least 5%, sometimes at least 10%, and occasionally at least 15%.} ^{[0043] Exemplary types of compounds that can be used to end-functionalize the reactive} ^{branched polymers of this invention include imines, amines, hydrocarbyloxy silanes, amine-} ^{containing hydrocarbyloxy silanes, halogenated organics, trialkyl tin compounds, carbon} _{dioxide, benzophenones, benzaldehydes, imidazolidones, pyrrolidinones, carbodiimides,} _{ureas, isocyanates, and Schiff bases. It should also be appreciated that two or more different} _{species of functionalizing agent can be employed in practicing the present invention.} HYDROCARBYLOXY SILANE FUNCTIONALIZING AGENTS ^{[0044] In one or more embodiments, hydrocarbyloxy silane functionalizing agents may} _{be defined by the formula:} (^{R1)4-z-ySi(R2) y (OR2)z} ^{where R1 is a halogen atom or a monovalent organic group, each R2 is a monovalent organic} _{group, z is an integer from 1 to 4, and y is an integer from 0 to 2. In one embodiment, the} _{halogen atom is chlorine.} ^{[0045] In one or more embodiments, the monovalent organic groups include hydrocarbyl} ^{groups such as, but not limited to, alkyl, cycloalkyl, alkenyl, cycloalkenyl, aryl, allyl, aralkyl,} ^{alkaryl, or alkynyl groups. Hydrocarbyl groups also include substituted hydrocarbyl groups,} ^{which refer to hydrocarbyl groups in which one or more hydrogen atoms have been replaced} ^{by a substituent such as a hydrocarbyl group. In one or more embodiments, these groups} _{may include from one, or the appropriate minimum number of carbon atoms to form the} _{group, to about 20 carbon atoms. These groups may or may not contain heteroatoms.} _{Suitable heteroatoms include, but not limited to, nitrogen, boron, oxygen, silicon, sulfur, tin,} _{and phosphorus atoms. In one or more embodiments, the cycloalkyl, cycloalkenyl, and aryl} _{groups are non-heterocyclic groups. In these or other embodiments, the substituents} _{forming substituted hydrocarbyl groups are non-heterocyclic groups.} ^{[0046] Suitable examples of siloxane terminating agents include tetraalkoxysilanes,} _{alkylalkoxysilanes, arylalkoxysilanes, alkenylalkoxysilanes, and haloalkoxysilanes.} ^{[0047] Examples of tetraalkoxysilane compounds include tetramethyl orthosilicate,} _{tetraethyl orthosilicate, tetrapropyl orthosilicate, tetrabutyl orthosilicate, tetra(2-} _{ethylhexyl) orthosilicate, tetraphenyl orthosilicate, and tetratoluyloxysilane.} ^{[0048] Examples of alkylalkoxysilane compounds include methyltrimethoxysilane,} ^{methyltriethoxysilane, methyltri-n-propoxysilane, methyltri-n-butoxysilane,} ^{methyltriphenoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltri-n-} _{propoxysilane, ethyltri-n-butoxysilane, ethyltriphenoxysilane, dimethyldimethoxysilane,} _{dimethyldiethoxysilane, dimethyldi-n-propoxysilane, dimethyldi-n-butoxysilane,} _{dimethyldiphenoxysilane, diethyldimethoxysilane, and diphenyldimethoxysilane.} ^{[0049] Examples of arylalkoxysilane compounds include phenyltrimethoxysilane,} _{phenyltriethoxysilane, phenyltri-n-propoxysilane, phenyltri-n-butoxysilane, and} _{phenyltriphenoxysilane.} ^{[0050] Examples of alkenylalkoxysilane compounds include vinyltrimethoxysilane,} ^{vinyltriethoxysilane, vinyltri-n-propoxysilane, vinyltri-n-butoxysilane,} _{vinyltriphenoxysilane, allyltrimethoxysilane, octenyltrimethoxysilane, and} _{divinyldimethoxysilane.} ^{[0051] Examples of haloalkoxysilane compounds include trimethoxychlorosilane,} ^{triethoxychlorosilane, tri-n-propoxychlorosilane, tri-n-butoxychlorosilane,} ^{triphenoxychlorosilane, dimethoxydichlorosilane, diethoxydichlorosilane, di-n-} ^{propoxydichlorosilane, diphenoxydichlorosilane, methoxytrichlorosilane,} ^{ethoxytrichlorosilane, n-propoxytrichlorosilane, phenoxytrichlorosilane,} ^{trimethoxybromosilane, triethoxybromosilane, tri-n-propoxybromosilane,} _{triphenoxybromosilane, dimethoxydibromosilane, diethoxydibromosilane, di-n-} _{propoxydibromosilane, diphenoxydibromosilane, methoxytribromosilane,} _{ethoxytribromosilane, n-propoxytribromosilane, phenoxytribromosilane,} _{trimethoxyiodosilane, triethoxyiodosilane, tri-n-propoxyiodosilane, triphenoxyiodosilane,} _{dimethoxydiiodosilane, di-n-propoxydiiodosilane, diphenoxydiiodosilane,} _{methoxytriiodosilane, ethoxytriiodosilane, n-propoxytriiodosilane, and} _{phenoxytriiodosilane.} ^{[0052] Techniques for preparing functionalized polymers by using hydrocarbyloxy silane} _{compounds are set forth in U.S. Patent Nos. 3,244,664; 6,008,295; 6,228,908; and} _{4,185,042, which are incorporated herein by reference.} ^{[0053] In one or more embodiments, hydrocarbyloxy silane functionalizing agents is an} _{imino-containing hydrocarbyloxy silane that may be defined by the formula:} R³ R⁵ ^{where R2, R3, and R7}

^{divalent organic group, and} _{where R5 and R6 are each independently hydrocarbyloxy groups or hydrocarbyl groups.} ^{[0054] In one or more embodiments, the divalent organic group is a hydrocarbylene} ^{groups such as, but not limited to, alkylene, cycloalkylene, alkenylene, cycloalkenylene,} ^{alkynylene, cycloalkynylene, or arylene groups. Hydrocarbylene groups include substituted} ^{hydrocarbylene groups, which refer to hydrocarbylene groups in which one or more} ^{hydrogen atoms have been replaced by a substituent such as a hydrocarbyl group. In one or} ^{more embodiments, these groups may include from one, or the appropriate minimum} _{number of carbon atoms to form the group, to about 20 carbon atoms. These groups may or} _{may not contain heteroatoms. Suitable heteroatoms include, but not limited to, nitrogen,} _{boron, oxygen, silicon, sulfur, tin, and phosphorus atoms. In one or more embodiments, the} _{cycloalkylene, cycloalkenylene, and arylene groups are non-heterocyclic groups. In these or} _{other embodiments, the substituents forming substituted hydrocarbylene groups are non-} _{heterocyclic groups.} ^{[0055] Examples of these imino-containing hydrocarbyloxy silane compounds include} ^{triethoxy compounds such as, but are not limited to, N-(1,3-dimethylbutylidene)-3-} ^{(triethoxysilyl)-1-propaneamine, N-(1-methylethylidene)-3-(triethoxysilyl)-1-} _{propaneamine, N-ethylidene-3-(triethoxysilyl)-1-propaneamine, N-(1-methylpropylidene)-} _{3-(triethoxysilyl)-1-propaneamine, N-(4-N,N-dimethylaminobenzylidene)-3-} _{(triethoxysilyl)-1-propaneamine, and N-(cyclohexylidene)-3-(triethoxysilyl)-1-} ^{propaneamine. Other examples include trimethoxy compounds such as, but not limited to,} ^{N-(1,3-dimethylbutylidene)-3-(trimethoxysilyl)-1-propaneamine, N-(1-methylethylidene)-} ^{3-(trimethoxysilyl)-1-propaneamine, N-ethylidene-3-(trimethoxysilyl)-1-propaneamine, N-} ^{(1-methylpropylidene)-3-(trimethoxysilyl)-1-propaneamine, N-(4-N,N-} ^{dimethylaminobenzylidene)-3-(trimethoxysilyl)-1-propaneamine, and N-} ^{(cyclohexylidene)-3-(trimethoxysilyl)-1-propaneamine. Other examples include} ^{methyldiethoxy compounds such as, but not limited to, N-(1,3-dimethylbutylidene)-3-} ^{(methyldiethoxysilyl)-1-propaneamine, N-(1-methylethylidene)-3-(methyldiethoxysilyl)-1-} ^{propaneamine, N-ethylidene-3-(methyldiethoxysilyl)-1-propaneamine, N-(1-} _{methylpropylidene)-3-(methyldiethoxysilyl)-1-propaneamine, N-(4-N,N-} _{dimethylaminobenzylidene)-3-(methyldiethoxysilyl)-1-propaneamine, and N-} _{(cyclohexylidene)-3-(methyldiethoxysilyl)-1-propaneamine. Other examples include} _{ethyldimethoxy compounds such as, but not limited to, N-(1,3-dimethylbutylidene)-3-} _{(ethyldimethoxysilyl)-1-propaneamine, N-(1-methylethylidene)-3-(ethyldimethoxysilyl)-1-} _{propaneamine, N-ethylidene-3-(ethyldimethoxysilyl)-1-propaneamine, N-(1-} _{methylpropylidene)-3-(ethyldimethoxysilyl)-1-propaneamine, N-(4-N,N-} _{dimethylaminobenzylidene)-3-(ethyldimethoxysilyl)-1-propaneamine, and N-} _{(cyclohexylidene)-3-(ethyldimethoxysilyl)-1-propaneamine.} ^{[0056] Techniques for preparing functionalized polymers by using imine-containing} _{hydrocarbyloxy compounds are disclosed in U.S. Publication Nos. 2005/0009979;} _{2010/0113683; and 2011/0092633, which are incorporated herein by reference.} ^{[0057] In one or more embodiments, hydrocarbyloxy silane functionalizing agents is a} _{hydrocarbyloxy silane defined by the formula:} R⁵

^{where R4 is a divalent organic group, where R5 and R6 are each independently} g_{roups or hydrocarbyl groups, R5}

_{a monovalent organic group, and A is} ^{selected from the group consisting of carboxylic ester, cyclic tertiary amine, non-cyclic} _{tertiary amine, pyridine, silazane, and sulfide groups.} ^{[0058] Examples of hydrocarbyloxy silane compounds including a carboxylic ester group} ^{include, but are not limited to, 3-methacryloyloxypropyltriethoxysilane, 3-} _{methacryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropylmethyldiethoxysilane,} _{and 3-methacryloyloxypropyltriisopropoxysilane.} ^{[0059] Examples of hydrocarbyloxy silane compounds including a cyclic tertiary amine} ^{group include, but are not limited to, 3-(1-hexamethyleneimino)propyltriethoxysilane, 3-(1-} ^{hexamethyleneimino)propyltrimethoxysilane, (1-hexamethyleneimino)methyltriethoxysilane,} ^{(1-hexamethyleneimino)methyltrimethoxysilane, 2-(1-} _{hexamethyleneimino)ethyltriethoxysilane, 3-(1-hexamethyleneimino)ethyltrimethoxysilane,} _{3-(1-pyrrolidinyl)propyltrimethoxysilane, 3-(1-pyrrolidinyl)propyltriethoxysilane, 3-(1-} _{heptamethyleneimino)propyltriethoxysilane, 3-(1-} _{dodecamethyleneimino)propyltriethoxysilane, 3-(1-} _{hexamethyleneimino)propyldiethoxyethylsilane, and 3-[10-(triethoxysilyl)decyl]-4-} _oxazoline. ^{[0060] Examples of hydrocarbyloxy silane compounds including a non-cyclic tertiary} ^{amine group include, but are not limited to, 3-dimethylaminopropyltriethoxysilane, 3-} ^{dimethylaminopropyltrimethoxysilane, 3-diethylaminopropyltrimethoxysilane, 3-} ^{diethylaminopropyltriethoxysilane, 2-dimethylaminoethyltriethoxysilane, 2-} _{dimethylaminoethyltrimethoxysilane, 3-dimethylaminopropyldiethoxymethylsilane, 3-} _{diethylaminopropyldiethoxymethylsilane,} _{3-dimethylaminopropyldimethoxymethylsilane, 3-} _{diethylaminopropyldimethoxymethylsilane, and 3-dibutylaminopropyltriethoxysilane} ^{[0061] Examples of hydrocarbyloxy silane compounds including a pyridine group} _{include, but are not limited to, 2-trimethoxysilylethylpyridine.} ^{[0062] Examples of hydrocarbyloxy silane compounds including a silazane group} ^{include, but are not limited to, N,N-bis(trimethylsilyl)-aminopropylmethyldimethoxysilane,} _{1-trimethylsilyl-2,2-dimethoxy-1-aza-2-silacyclopentane, N,N-} _{bis(trimethylsilyl)aminopropyltrimethoxysilane, N,N-} ^{bis(trimethylsilyl)aminopropyltriethoxysilane, N,N-} ^{bis(trimethylsilyl)aminopropylmethyldiethoxysilane, N,N-} ^{bis(trimethylsilyl)aminoethyltrimethoxysilane, N,N-} _{bis(trimethylsilyl)aminoethyltriethoxysilane, N,N-} _{bis(trimethylsilyl)aminoethylmethyldimethoxysilane, and N,N-} _{bis(trimethylsilyl)aminoethylmethyldiethoxysilane.} ^{[0063] Still other specific examples of useful functionalizing agents include trialkyltin} ^{halides such as triisobutyltin chloride, as disclosed in U.S. Patent Nos.4,519,431; 4,540,744;} ^{4,603,722; 5,248,722; 5,349,024; 5,502,129; and 5,877,336, which are incorporated herein} ^{by reference. Examples of useful halogenated organic compounds include cyclic amino} ^{compounds such as hexamethyleneimine alkyl chloride, as disclosed in U.S. Patent Nos.} ^{5,786,441; 5,916,976; and 5,552,473, which are incorporated herein by reference.} _{Additional examples include cyclic sulfur-containing or oxygen containing azaheterocycles} _{such as disclosed in WO 2004/020475; U.S. Publication No. 2006/0178467; and U.S. Patent} _{No. 6,596,798, which are incorporated herein by reference. Other examples include boron-} _{containing terminators such as disclosed in U.S. Patent No. 7,598,322, which is incorporated} _{herein by reference. Still other examples include cyclic siloxanes such as} _{hexamethylcyclotrisiloxane, including those disclosed in U.S. Patent No. 9,920,149, which is} _{incorporated herein by reference. Yet other examples include polydimethylsiloxanes.} AMOUNT OF FUNCTIONALIZATION AGENT USED ^{[0064] The amount of functionalizing employed in the practice of the present invention} ^{can be described with respect to the lithium or metal cation associated with the initiator. In} ^{one or more embodiments, the amount of functionalizing agent introduced to the} ^{polymerization mixture is greater than 0.70, in other embodiments greater than 0.75, in} ^{other embodiments greater than 0.80, in other embodiments greater than 0.85, and in other} _{embodiments greater than 0.90 moles of functionalizing agent per mole of lithium in the} _{initiator. In these or other embodiments, less than 0.99, in other embodiments less than} _{0.97, and in other embodiments less than 0.95 moles of functionalizing agent per mole of} _{lithium is introduced to the polymerization mixture. In one or more embodiments, from} _{about 0.7 to about 1.0, in other embodiments from about 0.75 to about 0.99, and in other} ^{embodiments from about 0.80 to about 0.97 moles of functionalizing agent per mole of} _{lithium is introduced to the polymerization mixture.} FUNCTIONALIZATION REACTION ^{[0065] The reaction between the respective species of functionalizing agents and the} _{polymer can take place by introduction the functionalizing agent sequentially or} _{simultaneously to the reactive polymer.} ^{[0066] In one or more embodiments, the reaction between the functionalizing agent and} ^{the reactive polymer may take place at a temperature from about 10 °C to about 150 °C, and} ^{in other embodiments from about 20 °C to about 100 °C. The time required for completing} ^{the reaction between the functionalizing agent and the reactive polymer depends on various} _{factors such as the type and amount of the initiator used to prepare the reactive polymer, the} _{type and amount of the functionalizing agent, as well as the temperature at which the} _{functionalization reaction is conducted. In one or more embodiments, the reaction between} _{the functionalizing agent and the reactive polymer can be conducted for about 10 to 60} _minutes. ^{[0067] In one or more embodiments, the functionalizing agent is introduced to the} ^{polymer cement (i.e. polymerization mixture) while the polymer is dissolved or suspended} ^{within a solvent. As those skilled in the art appreciate, this solution may be referred to as a} ^{polymer cement, or more specifically as a reactive or living polymer cement. In one or more} _{embodiments, the characteristics of the polymer cement, such as its concentration, will be} _{the same or similar to the characteristics of the cement prior to functionalization. The} _{composition including the functionalized polymer and solvent may be referred to as a} _{polymerization mixture; in other words, a polymerization mixture including a functionalized} _polymer. ^{[0068] In one or more embodiments, modification of the polymer (i.e., introduction of the} ^{functionalizing agent to the polymer cement), takes place within the same vessel in which} ^{the polymerization was conducted. In other embodiments, modification of the polymer} _{takes place outside of the reaction vessel in which the polymerization takes place. For} _{example, the first and second functionalizing agents can be introduced to the polymerization} _{mixture (i.e. polymer cement) in a downstream vessel or a downstream transfer conduit.} ^{[0069] According to one or more embodiments, as a result of the functionalization} ^{reaction, greater than 60 mol %, in other embodiments greater than 70 mol %, in other} ^{embodiments greater than 80 mol %, in other embodiments greater than 85 mol %, in other} ^{embodiments greater than 90 mol %, and in other embodiments greater than 95 mol % of} ^{the polymer chains within the polymer cement include a terminal functional group (i.e. the} _{residue of a functionalizing agent). In one or more embodiments, from about 60 to about 100} _{mol %, in other embodiments from about 70 to about 99 mol %, in other embodiments from} _{about 80 to about 98 mol %, and in other embodiments from about 90 to about 97 mol % of} _{the polymer chains within the polymer composition include the terminal functional group.} ^{[0070] According to one or more embodiments, as a result of the functionalization} ^{reaction, greater than 80 mol %, in other embodiments greater than 90 mol %, in other} _{embodiments greater than 95 mol %, and in other embodiments greater than 99 mol % of} _{the polymer chains within the polymer cement include terminal functional groups at both} _{ends of the polymer (i.e. are telechelic polymers).} POST FUNCTIONALIZATION POLYMER STABILIZATION ^{[0071] In one or more embodiments, following modification, the modified polymer (i.e.} ^{the telechelic polymer may optionally be stabilized (i.e. post-functionalization stabilized).} ^{That is, the modified polymer may be stabilized by introducing a stabilizing agent to the} _{polymerization mixture including the modified polymer. It is believed that the stabilizing} _{agent reacts with certain terminal functional groups (e.g. a hydrocarbyloxy substituent), and} _{it is believed that this reaction may take place at the introduction of the two molecules or} _{after aging of the composition.} ^{[0072] In one or more embodiments, stabilizing agents known in the art may be used.} ^{For example, the stabilizing agents may include alkylalkoxy silanes as disclosed in U.S. Patent} ^{No. 6,255,404, which is incorporated herein by reference. Exemplary alkylalkoxy silanes} ^{include octyltriethoxy silane. In other embodiments, the stabilizing agent may include long-} _{chain alcohols as disclosed in U.S. Patent No. 6,279,632, which is incorporated herein by} _{reference. Exemplary long chain alcohols include sorbitan stearate or sorbitan monoleate.} _{In still other embodiments, the polymers may be stabilized by treatment with an alkylalkoxy} ^{silane followed by treatment with a silane including a hydrolyzable group that forms an} _{acidic species upon hydrolysis, such as methyltrichlorosilane, as disclosed in U.S. Patent No.} _{9,546,237, which is incorporated herein by reference.} ^{[0073] In one or more embodiments of this invention, the use of aryl silanols (also known} ^{as hydroxy phenyl silanes) is advantageously used as a stabilizing agent. Useful aryl silanols} ^{are disclosed in U.S. Patent No. 9,255,167, which is incorporated herein by reference.} _{Exemplary aryl silanols include, but are not limited to, triphenylsilanol, which is also referred} _{to as hydroxytriphenylsilane, diphenylsilanediol, which is also referred to as} _{dihydroxydiphenylsilane, and phenylsilanetriol, which is also referred to as} _{trihydroxy(phenyl)silane.} ^{[0074] In one or more embodiments, the functionalized polymers of this invention may be} ^{stabilized by treatment with an aryl silanol (e.g. aryl silane diol or aryl silane triol)} ^{contemporaneously or followed by treatment with a silane including a hydrolyzable group} _{that forms an acidic species upon hydrolysis. Silanes including a hydrolyzable group that form} _{an acidic species upon hydrolysis are disclosed in U.S. Patent No. 9,546,237, which is} _{incorporated herein by reference. In particular embodiments, the functionalized polymers are} _{treated with diphenyl silane diol and trimethyl silyl chloride.} ^{[0075] In one or more embodiments, the stabilizing agent is added to the polymer cement} ^{after a sufficient time is provided to allow completion of the reaction between the reactive} ^{polymer and the functionalizing agent. In one or more embodiments, the stabilizing agent is} _{introduced to the polymer cement after 30 minutes, in other embodiments after 15 minutes,} _{and in other embodiments after 10 minutes from the time that the functionalizing agent is} _{introduced to the polymer cement.} ^{[0076] The amount of stabilizing agent (e.g. aryl silanol) employed in the practice of the} ^{present invention can be described with respect to the moles of lithium associated with the} ^{initiator. In one or more embodiments, greater than 0.5, in other embodiments greater than} _{1, in other embodiments greater than 2, and in other embodiments greater than 3 moles of} _{stabilizing agent per mole of lithium in the initiator is introduced to the polymerization} _{mixture. In these or other embodiments, less than 8, in other embodiments less than 7, in} _{other embodiments less than 6, in other embodiments less than 5, and in other embodiments} ^{less than 4.5 moles of stabilizing agent per mole of lithium is introduced to the} ^{polymerization mixture. In one or more embodiments, from about 1 to about 7, in other} _{embodiments from about 2 to about 6, and in other embodiments from about 3 to about 5} _{moles of stabilizing agent per mole of lithium is introduced to the polymerization mixture.} ^{[0077] In other embodiments, the amount of stabilizing agent (e.g. aryl silanol) employed} ^{in the practice of the present invention can be described as a molar ratio relative to the moles} ^{of functionalizing agent employed. In one or more embodiments, the ratio of the moles of} ^{stabilizing agent to the moles of functionalizing agent employed is from about 0.5:1 to about} _{8:1; in other embodiments from about 1:1 to about 7:1, in other embodiment from about 2:1} _{to about 6:1, and in other embodiments from about 3:1 to about 5:1. In these or other} _{embodiments, the ratio of the moles of stabilizing agent to the moles of functionalizing agent} _{employed is less than 7:1, in other embodiments less than 6:1, in other embodiments less} _{than 5.5:1, in other embodiments less than 5:1, and in other embodiments less than 4.5:1.} ^{[0078] Where two reagents are employed, such as where the polymer is treated with an} ^{aryl silanol (e.g. aryl silane diol or aryl silane triol) together with a silane including a} ^{hydrolysable group that forms an acidic species upon hydrolysis (e.g. hydrocarbyl silyl} ^{chloride such as trimethyl silyl chloride), the amount of the respective reagents employed} ^{may be the same or different. In one or more embodiments, the total amount of stabilizer} ^{employed (i.e. both compounds) is, when described as a molar ratio relative to the moles of} _{functionalizing agent, from about 3:1 to about 10:1, in other embodiments from about 4:1 to} _{about 8:1, and in other embodiments from about 5:1 to about 7:1. In these or other} _{embodiments, the molar ratio of the aryl silanol to the silane including a hydrolysable group} _{that forms an acidic species upon hydrolysis is from about 0.5:1 to about 4:1, in other} _{embodiments from about 1:1 to about 3:1, and in other embodiments from about 1.5:1 to} _{about 2.5:1.} ^{[0079] In one or more embodiments, the stabilization of the polymer (i.e., introduction of} ^{the stabilizing agent) takes place within the same vessel in which the polymerization took} ^{place. In these embodiments, this will include the same vessel in which the modification took} _{place. In other embodiments, stabilization of the polymer (i.e., introduction of the stabilizing} _{agent) takes place outside of the vessel in which the polymerization took place. Likewise, in} ^{one or more embodiments, stabilization of the polymer takes place outside of the vessel in} ^{which the modification of the polymer took place. For example, in one or more} ^{embodiments, the stabilizing agent can be added to the polymerization mixture (i.e., polymer} ^{cement) in a vessel or transfer line that is downstream of the vessel in which the} ^{polymerization took place and that is downstream of the vessel in which the polymer} _{modification took place. For purposes of this specification, relative to the polymerization} _{vessel, the vessel or conduit in which the stabilizing agent is introduced may be referred to} _{as a second vessel or second reaction zone. In other embodiments, the stabilizing agent may} _{be introduced to the polymer while the polymer is suspended or dissolved within monomer.} CONDENSATION ACCELERATOR ^{[0080] In one or more embodiments, after the introduction of the functionalizing agent} ^{to the reactive polymer, optionally after the addition of a quenching agent and/or} ^{antioxidant, optionally after or together with the stabilizing agent, and optionally after} ^{recovery or isolation of the functionalized polymer, a condensation accelerator can be added} ^{to the polymerization mixture. Useful condensation accelerators include tin and/or titanium} ^{carboxylates and tin and/or titanium alkoxides. One specific example is titanium 2-} ^{ethylhexyl oxide. Useful condensation catalysts and their use are disclosed in U.S.} _{Publication No. 2005/0159554 (Patent No. US 7,683,151), which is incorporated herein by} _{reference. In other embodiments, an organic acid can be used as a condensation accelerator.} _{Useful types of organic acids include aliphatic, cycloaliphatic and aromatic monocarboxylic,} _{dicarboxylic, tricarboxylic and tetracarboxylic acids. Specific examples of useful organic} _{acids include, but are not limited to, acetic acid, propionic acid, butyric acid, hexanoic acid,} _{2-methylhexanoic acid, 2-ethylhexanoic acid, cyclohexanoic acid and benzoic acid.} ^{[0081] The amount of condensation accelerator employed in the practice of the present} ^{invention can be described with respect to the moles of lithium associated with the initiator.} ^{In one or more embodiments, the moles of condensation accelerator per mole of lithium is} _{greater than 1.0, in other embodiments greater than 1.5, and in other embodiments greater} _{than 1.8 moles of condensation accelerator per mole of lithium in the initiator. In these or} _{other embodiments, less than 4.0, in other embodiments less than 3.3, and in other} _{embodiments less than 3.0 moles of condensation accelerator per mole of lithium is} ^{introduced to the polymerization mixture. In one or more embodiments, from about 1.0 to} ^{about 4.0, in other embodiments from about 1.5 to about 3.3, and in other embodiments from} _{about 1.8 to about 3.0 moles of condensation accelerator per mole of lithium is introduced} _{to the polymerization mixture.} ANTIOXIDANT ^{[0082] In one or more embodiments, after the introduction of the functionalizing agent} ^{to the reactive polymer, optionally after the addition of a quenching agent and/or} ^{antioxidant, optionally after or together with the stabilizing agent, and optionally after} _{recovery or isolation of the functionalized polymer, an antioxidant can be added to the} _{polymerization mixture. Exemplary antioxidants include 2,6-di-tert-butyl-4-methylphenol.} ^{[0083] In one or more embodiments, after formation of the polymer, a processing aid and} _{other optional additives such as oil can be added to the polymer cement.} OPTIONAL QUENCHING ^{[0084] In one or more embodiments, after the polymerization reaction, or after the} ^{reaction between the reactive polymer and the functionalizing agent has been accomplished} ^{or completed, a quenching agent can be added to the polymerization mixture in order to} ^{inactivate any residual reactive polymer chains and the catalyst or catalyst components. The} _{quenching agent may include a protic compound, which includes, but is not limited to, an} _{alcohol, a carboxylic acid, an inorganic acid, water, or a mixture thereof. The amount of} _{quenching agent employed may be in the range of 0.5 to 10 moles of quenching agent per} _{mole of lithium used to initiate the polymerization.} POLYMER DESOLVENTIZATION ^{[0085] Following polymerization and/or polymer modification, optional stabilization,} ^{optional introduction of a condensation accelerator and/or introduction of an antioxidant,} ^{the polymer product can be separated from the solvent, which may be referred to as} _{desolventization. In other words, as described above, the polymers are synthesized in an} _{organic solvent, and during the step of desolventization, the organic solvent is separated} _{from the resulting polymer.} ^{[0086] In particular embodiments, desolventization includes hot water and/or steam} _{coagulation. For example, the polymerization mixture, which includes the blend of modified} ^{polymers, can be combined with a steam or hot water stream. The heat associated with the} ^{steam or hot water stream volatilizes the solvent and any unreacted monomer. The polymer} _{product is then dispersed within an aqueous phase in, for example, the form of polymer} _{crumb. The nature and size of the polymer crumb can generally be manipulated by the} _{introduction of mechanical energy (e.g., in the form of mixers).} ^{[0087] In one or more embodiments, the polymer crumb is temporarily stored as a crumb} ^{dispersion within the water until subsequent drying steps, which are described below. The} ^{crumb dispersion is generally a mixture of polymer particles or crumb and water. The} _{polymer particles, which may also be referred to as coagulated polymer, are generally on the} _{macroscale and have at least on dimension that is greater than one mm. This crumb} _{dispersion may be contained within a tank, such as a conventional reactor tank such as a} _{continuously stirred tank reactor.} ^{[0088] In one or more embodiments, the polymer crumb can be further processed to} ^{remove residual solvent and dry the polymer (i.e., separate the polymer from the water). In} ^{practicing the present invention, the polymer can be dried by using conventional techniques,} _{which may include one or more of filtering, pressing, and heating. Following desolventization} _{and drying, the volatile content of the dried polymer can be below 2.0 %, in other} _{embodiments below 1.0 %, and in other embodiments below 0.5% by weight of the polymer.} ^{[0089] In other embodiments, the polymer product can be desolventized by employing} ^{devolatilizers, which are extruder-type devices that can operate in conjunction with heat} _{and/or vacuum. In yet other embodiments, the polymerization mixture can be directly drum} _dried. ^{[0090] Regardless of the methods used to desolventize and dry the polymer, the finished} _{polymer product may be referred to as a dried polymer. Using conventional techniques, the} _{dried polymer can be molded or otherwise manipulated into a bale.} CHARACTERISTIC OF LINEAR TELECHELIC POLYMERS ^{[0091] The functionalized polymers produced according to aspects of the present} ^{invention may be characterized by Mooney viscosity, which is determined according to by} _{using a Mooney viscometer (e.g. Agilent viscometer) with a large rotor at 100 °C with a 4} _{minute run time after 1 minute of preheating (i.e. ML 1+4 @ 100 °C). In one or more} ^{embodiments, the functionalized polymers have a Mooney viscosity of greater than 20, in} ^{other embodiments greater than 30, and in other embodiments greater than 40. In these or} ^{other embodiments, the functionalized polymers have a Mooney viscosity of less than 80, in} _{other embodiments less than 70, and in other embodiments less than 60. In one or more} _{embodiments, the functionalized polymers have a Mooney viscosity of from about 20 to} _{about 80, in other embodiments from about 30 to about 70, and in other embodiments from} _{about 40 to about 60.} ^{[0092] The functionalized polymers produced according to aspects of the present} ^{invention may be characterized by a glass transition temperature (Tg), which is determined} ^{according to ASTM E1356-08 by using differential scanning calorimetry (DSC) techniques.} _{In one or more embodiments of less than -20, in other embodiments less than -30, and in} _{other embodiments less than -40 °C. In one or more embodiments, the functionalized} _{polymers have a Tg of from about -65 to about -30, in other embodiments from about -60 to} _{about -30, and in other embodiments from about -50 to about -40 °C.} INDUSTRIAL APPLICABILITY ^{[0093] In one or more embodiments, the linear telechelic polymers of the invention may} ^{be used in formulating vulcanizable rubber composition that may, for example, be useful in} _{the preparation of tire components. Rubber compounding techniques and the additives} _{employed therein are generally disclosed in The Compounding and Vulcanization of Rubber,} _{in Rubber Technology (2nd Ed. 1973).} ^{[0094] Generally speaking, these vulcanizable rubber compositions include a} ^{vulcanizable rubber component, reinforcing filler, and a curative or curative system. These} _{compositions may also optionally include metal activators, resins, and processing oils, as} _{well the various ingredients that may be conventionally included in these vulcanizable} _{rubber compositions.} ^{[0095] In one or more embodiments, the linear telechelic polymers of this invention may} ^{form all or part of the rubber component of the vulcanizable compositions. That is, the} _{rubber component may include other vulcanizable rubbers, which may also be referred to} _{as elastomeric polymers or simply elastomers.} ^{[0096] The rubber compositions can be prepared by using the linear telechelic polymers} ^{of this invention alone or together with other elastomers (i.e., polymers that can be} ^{vulcanized to form compositions possessing rubbery or elastomeric properties). Other} ^{elastomers that may be used include natural and synthetic rubbers. The synthetic rubbers} _{typically derive from the polymerization of conjugated diene monomers, the} _{copolymerization of conjugated diene monomers with other monomers such as vinyl-} _{substituted aromatic monomers, or the copolymerization of ethylene with one or more α-} _{olefins and optionally one or more diene monomers.} ^{[0097] Exemplary synthetic rubbers, synthetic polyisoprene, polybutadiene,} ^{polyisobutylene-co-isoprene, neoprene, poly(ethylene-co-propylene), poly(styrene-co-} ^{butadiene), poly(styrene-co-isoprene), poly(styrene-co-isoprene-co-butadiene),} ^{poly(isoprene-co-butadiene), poly(ethylene-co-propylene-co-diene), polysulfide rubber,} ^{acrylic rubber, urethane rubber, silicone rubber, epichlorohydrin rubber, and mixtures} _{thereof. These elastomers can have a myriad of macromolecular structures including linear,} _{branched, and star-shaped structures. Natural rubber is synthesized by and obtained from} _{plant life. For example, natural rubber can be obtained from Hevea rubber trees, guayule} _{shrub, gopher plant, mariola, rabbitbrush, milkweeds, goldenrods, pale Indian plantain,} _{rubber vine, Russian dandelions, mountain mint, American germander, and tall bellflower.} ^{[0098] Generally, the rubber compositions of this invention include from about 30 to} ^{about 65, in other embodiments from about 35 to about 60, and in other embodiments from} _{about 40 to about 55 weight percent rubber (i.e. the rubber component), based on the total} _{weight of the tire component, of rubber.} ^{[0099] In one or more embodiments, the rubber component of the rubber compositions} ^{of this invention include from about 1 to about 100 wt %, in other embodiments from about} _{10 to about 90 wt %, and in other embodiments from about 20 to about 80 wt % of the} _{branched polymers produced by the techniques of this invention.} ^{[00100] As indicated above, the rubber compositions may include fillers such as} ^{inorganic and organic fillers. Examples of organic fillers include carbon black and starch.} _{Examples of inorganic fillers include silica, aluminum hydroxide, magnesium hydroxide,} _{mica, talc (hydrated magnesium silicate), and clays (hydrated aluminum silicates). Carbon} ^{blacks and silicas are the most common fillers used in manufacturing tires. In certain} _{embodiments, a mixture of different fillers may be advantageously employed.} ^{[00101] The amount of total filler employed in the rubber compositions can be up to} ^{about 150 parts by weight per 100 parts by weight of rubber (phr), with about 5 to about} ^{125 phr, or about 30 to about 110 phr, being typical. In certain embodiments the total filler} _{content is greater than about 100 phr. In other embodiments, the total filler content is from} _{about 50 to about 100 phr, and in in further embodiments from about 55 to about 95 phr.} ^{[00102] In one or more embodiments, carbon blacks include furnace blacks, channel} ^{blacks, and lamp blacks. More specific examples of carbon blacks include super abrasion} ^{furnace blacks, intermediate super abrasion furnace blacks, high abrasion furnace blacks,} _{fast extrusion furnace blacks, fine furnace blacks, semi-reinforcing furnace blacks, medium} _{processing channel blacks, hard processing channel blacks, conducting channel blacks, and} _{acetylene blacks.} ^{[00103] In particular embodiments, the carbon blacks may have a surface area (EMSA)} ^{of at least 20 m2/g and in other embodiments at least 35 m2/g; surface area values can be} ^{determined by ASTM D-1765 using the cetyltrimethylammonium bromide (CTAB)} _{technique. The carbon blacks may be in a pelletized form or an unpelletized flocculent form.} _{The preferred form of carbon black may depend upon the type of mixing equipment used to} _{mix the rubber compound.} ^{[00104] In one or more embodiments, the amount of carbon black employed in the} ^{rubber compositions can be up to about 75 parts by weight per 100 parts by weight of rubber} _{(phr), with about 5 to about 6 parts by weight phr, or about 10 to about 55 parts by weight} _{phr, being used in exemplary embodiments.} ^{[00105] In one or more embodiments, silicas may be characterized by their surface} ^{areas, which give a measure of their reinforcing character. The Brunauer, Emmet and Teller} ^{(“BET”) method (described in J. Am. Chem. Soc., 1939, vol. 60, 2 p. 309-319) is a recognized} _{method for determining the surface area. The BET surface area of silica is generally less than} _{450 m2/g. Useful ranges of surface area include from about 32 to about 400 m2/g, about} _{100 to about 250 m2/g, and about 150 to about 220 m2/g. In one or more embodiments, the} ^{silica may be characterized by a pH of from about 5 to about 7 or slightly over 7, or in other} _{embodiments from about 5.5 to about 6.8.} ^{[00106] In certain embodiments, the silica employed in the rubber composition is} _{derived from rice husk ash only, and in other embodiments the rubber compositions do not} _{include silica from non-rice husk ash derived processes.} ^{[00107] Some commercially available silicas which may be used include Hi-SilTM 215, Hi-} ^{SilTM 233, and Hi-SilTM 190 (PPG Industries, Inc.; Pittsburgh, Pa.). Other suppliers of} _{commercially available silica include Grace Davison (Baltimore, Md.), Degussa Corp.} _{(Parsippany, N.J.), Rhodia Silica Systems (Cranbury, N.J.), and J.M. Huber Corp. (Edison, N.J.).} ^{[00108] In one or more embodiments, the rubber compositions may include from about} ^{1 to about 150, in other embodiments from about 5 to about 140, and in other embodiments} ^{from about 10 to about 130 parts by weight silica per 100 parts by weight rubber. In} ^{particular embodiments, the present invention includes rubber compositions with high silica} ^{loadings, such as loadings greater than 70, in other embodiments greater than 90, and in} ^{other embodiments greater than 110 parts by weight silica per 100 parts by weight rubber,} _{with the useful upper end being limited by the high viscosity imparted by silica. When silica} _{is used together with carbon black, the amount of the silica or carbon black can be can be} _{as low as about 1 phr. In one or more embodiments, where carbon black and silica are} _{employed in combination as a filler, the weight ratio of silica to total filler may be from} _{about 5% to about 99% of the total filler, or in other embodiments from about 10% to} _{about 90% of the total filler, or in yet other embodiments from about 50% to about 85% of} _{the total filler.} ^{[00109] In one or more embodiments, where silica is employed as a filler (alone or in} ^{combination with other fillers), a coupling agent may be added to the rubber compositions} ^{during mixing in order to enhance the interaction of silica with the elastomers. Useful} _{coupling agents are disclosed in U.S. Patent Nos. 3,842,111; 3,873,489; 3,978,103;} _{3,997,581; 4,002,594; 5,580,919; 5,583,245; 5,663,396; 5,674,932; 5,684,171;} _{5,684,172; 5,696,197; 6,608,145; 6,667,362; 6,579,949; 6,590,017; 6,525,118;} _{6,342,552; and 6,683,135; which are incorporated herein by reference.} ^{[00110] In one or more embodiments, the amount of coupling agent may be from about} ^{2 to about 30 wt %, in other embodiments from about 4 to about 25 wt %, and in other} _{embodiments from about 6 to about 20 wt % based on the weight of silica within the} _composition. ^{[00111] In one or more embodiments, where silica is employed as a filler (either alone} ^{or in combination with other fillers), a silica dispersing agent, which may include silica} ^{shielding agents, may be included in the rubber formulations. The use of one or more silica} ^{dispersing agents has been found to be particularly useful in practicing the present} ^{invention in view of the telechelic polymers and/or high silica loadings. In one or more} ^{embodiments, useful silica dispersing agents include alkyl alkoxysilanes, fatty acid esters} _{of hydrogenated or non-hydrogenated C5 or C6 sugars, polyoxyethylene derivatives of fatty} _{acid esters of hydrogenated or non-}

_{C5 or C6 sugars, and esters of polyols,} _{including glycols and polyhydroxy compounds, and mixtures thereof. In particular} _{embodiments, the silica dispersing agent is glycol monostearate. Useful silane dispersing} _{agents are disclosed in U.S. Patent Nos. 6,608,145, 7,799,870, 7,897,661, 8,962,746,} _{9,758,639, 9,951,208, and U.S. Publication Nos.2004/0152811, and 2005/0070672, which} _{are incorporated herein by reference.} ^{[00112] In other embodiments, useful silica dispersing agents include metal} ^{glycerolates such as zinc glycerolate, calcium glycerolate, and magnesium glycerolate.} _{These compounds are described in greater detail in U.S. Patent Nos. 10,087,306 and} _{11,220,595, and U.S. Publication No. 2021/0388188, which are incorporated herein by} _reference. ^{[00113] In one or more embodiments, the rubber compositions of the invention may} ^{include from about 0.1 to about 30 wt %, in other embodiments from about 1.0 to about 25} ^{wt %, in other embodiments from about 3.0 to about 20 wt %, and in other embodiments} ^{from about 4.0 to about 10 wt% silica dispersing agent based on the weight of the silica} _{within the composition. In one or more embodiments, the rubber compositions include} _{greater than 3 wt %, in other embodiments greater than 5 wt %, and in other embodiments} _{greater than 7 wt % dispersing agent based upon the weight of the silica. In these or other} _{embodiments, the rubber compositions may include greater than 3 parts by weight, in} ^{other embodiments greater than 4 parts by weight, in other embodiments greater than 5} _{parts by weight, and in other embodiments greater than 6 parts by weight silica dispersing} _{agent per 100 parts by weight rubber.} ^{[00114] A multitude of rubber curing agents (also called vulcanizing agents) may be} ^{employed, including sulfur or peroxide-based curing systems. Curing agents are described} ^{in Kirk-Othmer, Encyclopedia of Chemical Technology, Vol. 20, pgs. 365-468, (3rd Ed.} _{1982), particularly Vulcanization Agents and Auxiliary Materials, pgs. 390-402, and A.Y.} _{Coran, Vulcanization, Encyclopedia of Polymer Science and Engineering, (2nd Ed. 1989),} _{which are incorporated herein by reference. Vulcanizing agents may be used alone or in} _combination. ^{[00115] Other ingredients that are typically employed in rubber compounding may also} ^{be added to the rubber compositions. These include accelerators, accelerator activators, oils,} ^{plasticizer, waxes, scorch inhibiting agents, processing aids, zinc oxide, tackifying resins,} ^{reinforcing resins, fatty acids such as stearic acid, peptizers, and antidegradants such as} _{antioxidants and antiozonants. In particular embodiments, the oils that are employed} _{include those conventionally used as extender oils, which are described above. Generally, the} _{rubber compositions of this invention can include from about 1 to about 70 parts by weight,} _{or in other embodiments from about 5 to about 50 parts weight total oil per 100 parts by} _{weight rubber.} ^{[00116] All ingredients of the rubber compositions can be mixed with standard mixing} ^{equipment such as, but not limited to, Banbury mixers, Brabender mixers, intermesh mixers} ^{including tandem intermesh mixers, extruders, kneaders, and two-roll mills. In one or more} ^{embodiments, the ingredients are mixed in two or more stages. In the first stage (often} ^{referred to as the masterbatch mixing stage), a so-called masterbatch, which typically} ^{includes the rubber component and filler, is prepared. To prevent premature vulcanization} _{(also known as scorch), the masterbatch may exclude vulcanizing agents. The masterbatch} _{may be mixed at a starting temperature of from about 25 °C to about 125 °C with a discharge} _{temperature of about 135 °C to about 180 °C. Once the masterbatch is prepared, the} _{vulcanizing agents may be introduced and mixed into the masterbatch in a final mixing stage,} _{which is typically conducted at relatively low temperatures so as to reduce the chances of} ^{premature vulcanization. Optionally, additional mixing stages, sometimes called remills, can} ^{be employed between the masterbatch mixing stage and the final mixing stage. One or more} _{remill stages are often employed where the rubber composition includes silica as the filler.} _{Various ingredients including the polymers of this invention can be added during these} _remills. ^{[00117] The mixing procedures and conditions particularly applicable to silica-filled tire} ^{formulations are described in U.S. Patent Nos. 5,227,425; 5,719,207; and 5,717,022, as well} _{as European Patent No. 890,606, all of which are incorporated herein by reference. In one} _{embodiment, the initial masterbatch is prepared by including the polymer and silica in the} _{substantial absence of coupling agents and shielding agents.} ^{[00118] The rubber compositions prepared from the polymers of this invention are} ^{particularly useful for forming tire components such as treads, subtreads, sidewalls, body} ^{ply skims, bead filler, and the like. In one or more embodiments, these tread or sidewall} _{formulations may include from about 10% to about 100% by weight, in other embodiments} _{from about 35% to about 90% by weight, and in other embodiments from about 50% to} _{about 80% by weight of the polymer of this invention based on the total weight of the rubber} _{within the formulation.} ^{[00119] Where the rubber compositions are employed in the manufacture of tires, these} ^{compositions can be processed into tire components according to ordinary tire} ^{manufacturing techniques including standard rubber shaping, molding and curing} ^{techniques. Typically, vulcanization is effected by heating the vulcanizable composition in a} ^{mold; e.g., it may be heated to about 140 °C to about 180 °C. Cured or crosslinked rubber} _{compositions may be referred to as vulcanizates, which generally contain three-dimensional} _{polymeric networks that are thermoset. The other ingredients, such as fillers and processing} _{aids, may be evenly dispersed throughout the crosslinked network. Pneumatic tires can be} _{made as discussed in U.S. Patent Nos. 5,866,171; 5,876,527; 5,931,211; and 5,971,046,} _{which are incorporated herein by reference.} EXAMPLES ^{[00120] In order to demonstrate the practice of the present invention, the following} examples have been prepared and tested. The examples should not, however, be viewed as _{limiting the scope of the invention. The claims will serve to define the invention.} Experiment I INITIATOR PREPARATION ^{[00121] 8.1 mL of sec-butyl lithium (sBuLi) and 0.97 mL of diisopropenylbenzene (DIPB)} ^{were charged to a small glass bottle. After vigorous shaking, 0.79 mL of triethylamine} _{(NEt3)was charged to the bottle. The bottle was again shaken vigorously and agitated in a} _{50 °C water bath for 2 hours. The resulting initiator (which may be referred to as DiLi} _{initiator) was either quickly used or refrigerated prior to use.} POLYMER SYNTHESIS ^{[00122] Four large bottles were each charged with 98.7 g of hexanes, followed by 15 g of} ^{styrene (33 wt %). The bottles were vented and 216.26 g of butadiene (21 wt %) was} ^{charged in each bottle. 0.15 mL of 1.6 M 2,2-di-(2-tetrahydrofuryl)propane was added to} ^{each bottle. Finally, 0.72 mL of the DiLi initiator solution was added to each bottle and the} ^{bottles were placed in a 50 °C water bath for 2 hours. After 2 hours, functionalizing agent as} ^{charged to each bottle as provided in Table 1 (except bottle 1). The bottles were again placed} _{in the 50 °C water bath and agitated for 30 minutes. After 30 minutes, 3 mL of IPA/BHT was} _{added to each bottle to quench the reaction. The polymers were then coagulated in IPA/BHT} _{and drum dried. As shown in Table I, N,N-bis(trimethylsilyl)-} _{aminopropylmethyldimethoxysilane (APMDMOS), glycidoxypropylmethyldiethoxysilane} _{(GPMDEOS), 3-(1,3-dimethylbutylidene)aminopropyltriethoxysilane (DMBAPTEOS) were} _{employed as functionalizing agents.} POLYMER TESTING ^{[00123] The physical properties of the polymers were analyzed by NMR, GPC and DSC.} ^{The total nitrogen content analysis was also performed on these polymers. The number} _{average (Mn), weight average (Mw) molecular weights and polydispersity (PDI) were} _{determined by gel permeation chromatography (GPC) using a Tosoh Ecosec HLC-8320 GPC} _{system and Tosoh TSKgel GMHxl-BS columns with THF as a solvent. The system was} ^{calibrated using polystyrene (PS) standards and referenced to PS and SBR standards. The} ^{styrene and vinyl content of the polymer was determined by 300 MHz NMR using CDCl3 as} ^{the solvent. Polymer Mooney viscosities were determined using a Monsanto Mooney} _{viscometer. The ML(1+4) values were measured on a large rotor at 100 °C for 4 minutes with} _{a 1 minute of warm up time. Total nitrogen analysis was performed on (3x) coagulated} _{samples using Mitsubishi Chemical Analytech NSX-2100 Elemental Analyzer System.} Table I Samples I-1 I-2 I-3 I-4 F_{unctional Group None APMDMOS GPMDEOS} ^{GPMDEOS +} D_MBAPTEOS Functional Group:Li (eq.) - 1.1 1.1 0.45 + 0.25 M_{ass Recovered (g)} ^{48.1 50.8 48.8 49.3} Mn, Base Peak (PS Std) (kg/mol) 216 207 225 198 Mw, Base Peak (PS Std) (kg/mol) 234 224 243 212 Mw/Mn (PS Std) 1.08 1.08 1.08 1.07 Mn, Coupled Peak (PS Std) (kg/mol) -- -- 607 597 Mw, Coupled Peak (PS Std) (kg/mol) -- -- 730 790 Mw/Mn (PS Std) -- -- 1.20 1.32 % Coupling -- -- 22.82 33.31 % Styrene 10.9 13.0 10.8 11.0 % Vinyl 58.2 58.8 57.4 55.9 Tg (°C) -43.05 -43.48 -43.62 -44.9 Nitrogen (ppm) 26 224 -- 52 Silane/chain (Calculated from TN) 0 2 -- -- Experiment II INITIATOR PREPARATION ^{[00124] 2 eq. of sec-butyl lithium (sBuLi) (1.4 M in cyclohexane) and 1 eq. of neat} ^{diisopropenylbenzene (DIPB) were charged to a small glass bottle. After vigorous shaking,} _{1 eq. of neat trimethylamine (NEt3)was added to the bottle. The bottle was again shaken} ^{vigorously and agitated in a 50 °C water bath for 2 hours. The resulting initiator (DiLi} _{initiator) was either quickly used or refrigerated prior to use.} POLYMER PREPARATION – SAMPLE 1 ^{[00125] A steel vessel was charged with 2.64 lb hexanes, 0.45 lbs styrene (33 wt %) and} ^{6.68 lb butadiene (21 wt %) under agitation. 1.75 mL of 1.60 M 2,2-di-(2-} ^{tetrahydrofuryl)propane solution was then added followed by 8.39 mL of 0.58 M of the DiLi} ^{initiator solution. The jacket temperature was immediately set to 63 °C. The reaction} _{reached a peak temperature of 97.4 °C in about 22 minutes. About 30 minutes after peak,} _{the non-functional polymer was dropped into a solution of IPA/BHT (0.6 g BHT/100 mL IPA)} _{and coagulated. The coagulated polymer was drum dried and utilized for analytical} _evaluation. POLYMER PREPARATION – SAMPLE 2 ^{[00126] A stainless steel jacketed vessel was charged with 2.64 lb hexanes, 0.46 lb} ^{styrene (33 wt %) and 6.68 lb butadiene (21 wt %) 0.99 mL of 1.6 M 2,2-di-(2-} ^{tetrahydrofuryl)propane solution was charged to the reactor followed by addition of 2.04} ^{mL of 2.50 M n-BuLi solution and the jacket temperature was immediately set to 63 °C. The} ^{reaction reached a peak temperature of 82 °C in about 20 minutes. Fifteen minutes after} _{peak exotherm, about 600 mL of cement was dropped in 2 bottles and 3-(1,3-} _{dimethylbutylidene)aminopropylmethyldiethoxysilane (DMBAPDEOS) (1.1 eq/Li) was} _{added to each bottle. The bottles were agitated in a 50 °C water bath for 30 minutes. The} _{polymer was quenched by adding 3 mL IPA/BHT (0.6 g BHT/100 mL IPA), coagulated and} _{drum dried.} POLYMER PREPARATION – SAMPLE 3 ^{[00127] A stainless steel jacketed vessel was charged with 3.14 lb hexanes, 0.42 lb} ^{styrene (33 wt %) and 6.22 lb butadiene (21 wt %). 1.83 mL of 1.6 M 2,2-di-(2-} ^{tetrahydrofuryl)propane solution was charged to the reactor followed by addition of 9.10} ^{mL of 0.58 M DiLi initiator solution and the jacket temperature was immediately set to 63} _{°C. The reaction reached a peak temperature of 102.9 °C in about 20 min. 15 min after peak} _{exotherm 3.69 mL of neat 3-(1,3-dimethylbutylidene) aminopropylmethyldiethoxysilane} _{(DMBAPDEOS) functional group was added to the reactor and the reaction was continued} ^{for another 30 min. The polymer cement was coagulated by dropping in IPA/BHT (0.6 g} _{BHT/100 mL IPA) solution and drum dried.} POLYMER PREPARATION – SAMPLE 4 ^{[00128] A stainless steel jacketed vessel was charged with 3.14 lb hexanes, 0.42 lb} ^{styrene (33 wt %) and 6.22 lb butadiene (21 wt %). 1.83 mL of 1.60 M 2,2-di-(2-} ^{tetrahydrofuryl)propane solution and 9.10 mL of DiLi initiator solution were added to the} ^{reactor and the jacket temperature was set at 63 °C. The reaction reached a peak} ^{temperature of 100.5 °C in about 23 minutes. 15 minutes after peak 3.69 mL of neat 3-(1,3-} _{dimethylbutylidene)aminopropylmethyldiethoxysilane (DMBAPDEOS) was added to the} _{reactor and the reaction was continued for another 30 minutes. After 30 minutes, about 650} _{mL of polymer cement was dropped into 10 large bottles and quenched with 3 mL IPA/BHT} _{(0.6 g BHT/100 mL IPA). The residual polymer cement in the reactor was coagulated in} _{IPA/BHT solution and drum dried for analysis.} POLYMER TESTING ^{[00129] Polymer Samples 1-4 were tested by using the methods provided above and the} _{results are reported in Table II.} Table II Samples II-1 II-2 II-3 II-4 Initiator DiLi n-BuLi DiLi DiLi Functional Group Non-functional DMBAPDEOS DMBAPDEOS DMBAPDEOS 1_{H NMR} % Styrene 11.1 10.5 11.1 10.8 % Vinyl 36.5 39.7 39.2 40.5 GPC Tosoh (PS Std) Base Mn (kg/mol) 195 193 185 170 Base Mw (kg/mol) 223 201 197 192 Base Mp (kg/mol) 214 202 198 200 Mw/Mn 1.14 1.04 1.07 1.13 % Coupling -- 37% 34% 24% Mooney Viscosity M^L ₍₁₊₄₎ ^(MU) _{13 18 34 40} T₈₀ (s) _{0.9 1.0 1.5 2.0} Total Nitrogen (ppm) 13 79 194 175 Experiment III INITIATOR PREPARATION ^{[00130] A small glass bottle was charged with 6.84 mL of sec-BuLi (1.4 M in cyclohexane)} ^{and 0.82 mL diisopropenylbenzene (neat, 5.58 M)(DIPB), the bottle was shaken vigorously,} _{then 0.67 mL triethylamine (NEt3)(neat, 7.17 M) was charged. The bottle was again shaken} _{vigorously then agitated in a 50 °C water bath for 2 hours. The catalyst solution (DiLi} _{initiator solution) was either quickly used or refrigerated prior to use.} POLYMER PREPARATION ^{[00131] A nitrogen-purged, jacketed stainless-steel reactor was charged with 2.90 lbs of} ^{anhydrous hexanes and 0.45 lbs of 33 weight % styrene in hexanes. The reactor was vented} ^{to 2 psi and 6.43 lbs of 21.0 weight % butadiene in hexanes was charged. 1.92 mL 2,2-bis(2’-} ^{tetrahydrofuryl)propane (1.6 M; 0.32 eq vs Li) was added to the reactor followed by the} ^{catalyst solution prepared as described above. The jacket temperature was set to 62.8 °C} ^{and the solution temperature and reactor pressure were monitored via sensors located} _{inside the vessel. The batch temperature peaked at 94.7 °C in about 25 minutes. 15 minutes} _{after peak, 6.5 mL of 3-(1,3-dimethylbutylidene) aminopropyldiethoxysilane (3.1 M, 1 eq Vs} _{Li) was added to the reactor and the reaction was continued for another 30 min. Samples of} _{the product cement were then collected through a needle into dried, purged, sealed 800 mL} _{bottles. The resulting polymer was characterized as follows: 12.6 % bound styrene, 44.5 %} _{vinyl, Tg = - 55 °C, Mn = 260 kg/mol, Mw 441 kg/mol, Mp = 199 kg/mol, and 44 % coupled.} POLYMER STABILIZATION ^{[00132] The polymer cement in each bottle prepared above was quenched by adding 3} ^{mL IPA/BHT solution. Then to each of 2 bottles containing approximately 400g of cement} ^{was added (1) diphenylsilanediol (0.1 M in 20% ethanol in cyclohexane)(DPSDO) and/or (2)} ^{triphenylsilanol (0.2 M in 20% ethanol in cyclohexane) (TPS) as shown in Table III. The} ^{bottles were agitated in a 50 °C water bath for 30 minutes. The cement from the bottle pairs} _{was then steam desolventized using a mini-steam desolventizer apparatus. To the water was} _{added 15g of polycoat (for Example III-1; the same water was used for subsequent samples} _{and 8 g of polycoat was added each time) and the water was heated to above 80 °C using} _{steam. With the agitator speed set as high as possible without causing splashing, the cement} ^{was poured from the bottles into the desolventizer in a slow, controlled manner resulting in} ^{crumbed material. The devolatilized material was collected and dried in an oven at 70 °C for} _{12 hours. A portion of the material was then oven-aged at 100 °C for 48 hours. The unaged} _{polymer properties were analyzed using the techniques outlined above.} Table III Samples III-1 III-2 III-3 III-4 III-5 DPSDO -- 2 4 -- 1 T_PS ^{-- -- -- 1 1} Total Mass of Cement (g) 795 799 817 819 815 Volume of Stabilizer Added (mL) -- 36 73 9 9/18 Unaged Data Gel Content 93% 12% 2% 14% 2% M^S ₍₁₊₄₎ ^{57.73 40.82 23.84 34.71 39.33} ^T ₈₀ ^(s) _{>900 29.76 8.57 9.89 7.74} Aged Data Gel Content 89% 39% 4% 49% 42% M^S ₍₁₊₄₎ 76.54* 88.07 61.33 87.48 87.5 T^{80 (s) >900 673.92 31.63 428.28 830.6} ^{[00133] Various modifications and alterations that do not depart from the scope and} _{spirit of this invention will become apparent to those skilled in the art. This invention is not} _{to be duly limited to the illustrative embodiments set forth herein.}

Claims

^{What is claimed is:} ^{1. A method for preparing a linear telechelic diene copolymer, the method comprising:} ^{(i) preparing a dilithium initiator by reacting dialkenyl compound with an} ^{alkyl lithium compound;} ^{(ii) introducing the dilithium initiator, diene monomer, vinyl aromatic} ^{monomer, and a randomizer to form a polymerization mixture;} ^{(iii) allowing the diene monomer and vinyl aromatic monomer to} ^{polymerize and form a polymer having first and second reactive ends; and} ^{(iv) functionalizing both the first and second reactive ends of the polymer} ^{by reacting the first and second reactive ends with first and second functionalizing} ^{agents to thereby form a linear telechelic diene copolymer.} ^{2. The method of claim 1, where the polyalkenyl compound is diisopropenyl benzene.} _{3. The method of any of the preceding claims, where the alkyl lithium is selected from} _{n-butyl lithium, t-butyl lithium, and sec-butyl lithium.} _{4. The method of any of the preceding claims, where said step of preparing a dilithium} _{initiator includes aging the initiator under inert atmosphere at a temperature of from} _{about 0 to about 150 ℃ for greater than 15 minutes.} _{5. The method of any of the preceding claims, where the molar ratio of moles of Li} _{associated with the alkyl lithium to equivalents of alkenyl groups associated with the} _{dialkenyl compound is from about 1.95:1 to about 2.05:1.} _{6. The method of any of the preceding claims, where said step of preparing a dilithium} _{initiator includes aging the initiator in the presence of a Lewis base.}

^{7. The method of any of the preceding claims, where the Lewis base is selected from the} ^{group consisting of 2,2-bis(2-oxolanyl)propane (also known as 2,2-} ^{ditetrahydrofurylpropane), meso-2,2-diterahydrofurylpropane, DL-2,2,-} ^{ditetrahdydrofurlypropane, tetramethylethylenediamine, and mixtures thereof.} ^{8. The method of any of the preceding claims, where the Lewis base trialkyl amine.} ^{9. The method of any of the preceding claims, where said step of preparing a dilithium} ^{initiator includes aging the initiator within a reaction mixture that includes a solvent} ^{in which the initiator is soluble.} ^{10. The method of any of the preceding claims, where said step of introducing the} ^{dilithium initiator, diene monomer, vinyl aromatic monomer, and a randomizer to} ^{form a polymerization mixture takes place with a solvent in which at least one of the} ^{dilithium initiator, diene monomer, vinyl aromatic monomer, a randomizer and} p_{olymer are soluble to thereby form a polymerization mixture.} _{11. The method of any of the preceding claims, where the polymer having first and second} _{reactive ends is characterized by at least one of an Mp of from about 160 to about 280,} _{an Mn of from about 130 to about 300, and an Mw of from about 180 to about 500.} _{12. The method of any of the preceding claims, where the polymer having first and second} _{reactive ends is monomodal and has a molecular weight distribution of less than 2.5.} _{13. The method of any of the preceding claims, where the polymer having first and second} _{reactive ends is characterized by a vinyl content of from about 5 to about 80%.} _{14. The method of any of the preceding claims, where the polymer having first and second} _{reactive ends is characterized by a bound styrene content of from about 20 to about} _{60 wt%.}

^{15. The method of any of the preceding claims, where the polymer having first and second} ^{reactive ends is characterized by a T80 of less than 2 seconds.} ^{16. The method of any of the preceding claims, where the first and second functionalizing} ^{agents are hydrocarbyloxy silanes.} ^{17. The method of any of the preceding claims, where the first and second functionalizing} a_{gents are the same type of functionalizing agent.} _{18. The method of any of the preceding claims, where the first and second functionalizing} _{agents are different types of functionalizing agents.} _{19. The method of any of the preceding claims, where the first and second functionalizing} _{agents are defined by the formula} R³ R⁵ ^{where R2, R3, and R7}

^{a divalent organic group,} ^{and where R5 and R6 are each independently hydrocarbyloxy groups or hydrocarbyl} ^groups. ^{20. The method of any of the preceding claims, where one of R5 and R6 is a} ^{hydrocarbyloxy group and the other of R5 and R6 is a hydrocarbyl group.} _{21. The method of any of the preceding claims, where at least one of the first and second} _{functionalizing agent is selected from the group consisting of N-(1,3-} _{dimethylbutylidene)-3-(triethoxysilyl)-1-propaneamine, N-(1-methylethylidene)-3-} _{(triethoxysilyl)-1-propaneamine, N-ethylidene-3-(triethoxysilyl)-1-propaneamine,} ^{N-(1-methylpropylidene)-3-(triethoxysilyl)-1-propaneamine, N-(4-N,N-} ^{dimethylaminobenzylidene)-3-(triethoxysilyl)-1-propaneamine, and N-} ^{(cyclohexylidene)-3-(triethoxysilyl)-1-propaneamine.} ^{22. The method of any of the preceding claims, where at least one of the first and second} ^{the functionalizing agent is selected from the group consisting of trimethoxy} ^{compounds such as, but not limited to, N-(1,3-dimethylbutylidene)-3-} ^{(trimethoxysilyl)-1-propaneamine, N-(1-methylethylidene)-3-(trimethoxysilyl)-1-} ^{propaneamine, N-ethylidene-3-(trimethoxysilyl)-1-propaneamine, N-(1-} ^{methylpropylidene)-3-(trimethoxysilyl)-1-propaneamine, N-(4-N,N-} ^{dimethylaminobenzylidene)-3-(trimethoxysilyl)-1-propaneamine, and N-} ^{(cyclohexylidene)-3-(trimethoxysilyl)-1-propaneamine.} ^{23. The method of any of the preceding claims, where at least one of the first and second} ^{the functionalizing agent is selected from the group consisting of methyldiethoxy} c_{ompounds such as, but not limited to, N-(1,3-dimethylbutylidene)-3-} _{(methyldiethoxysilyl)-1-propaneamine, N-(1-methylethylidene)-3-} _{(methyldiethoxysilyl)-1-propaneamine, N-ethylidene-3-(methyldiethoxysilyl)-1-} _{propaneamine, N-(1-methylpropylidene)-3-(methyldiethoxysilyl)-1-propaneamine,} _{N-(4-N,N-dimethylaminobenzylidene)-3-(methyldiethoxysilyl)-1-propaneamine,} _{and N-(cyclohexylidene)-3-(methyldiethoxysilyl)-1-propaneamine.} _{24. The method of any of the preceding claims, where at least one of the first and second} _{the functionalizing agent is selected from the group consisting of ethyldimethoxy} _{compounds such as, but not limited to, N-(1,3-dimethylbutylidene)-3-} _{(ethyldimethoxysilyl)-1-propaneamine, N-(1-methylethylidene)-3-} _{(ethyldimethoxysilyl)-1-propaneamine, N-ethylidene-3-(ethyldimethoxysilyl)-1-} _{propaneamine, N-(1-methylpropylidene)-3-(ethyldimethoxysilyl)-1-propaneamine,} _{N-(4-N,N-dimethylaminobenzylidene)-3-(ethyldimethoxysilyl)-1-propaneamine,} _{and N-(cyclohexylidene)-3-(ethyldimethoxysilyl)-1-propaneamine.}

^{25. The method of any of the preceding claims, where at least one of the first and second} t_{he functionalizing agent is defined by the formula} R⁵ ^{where R4 is a divalent}

^{and R6 are each independently}

^{groups or hydrocarbyl}

^{is a monovalent organic group, and} ^{A is selected from the group consisting of, carboxylic ester, cyclic tertiary amine, non-} ^{cyclic tertiary amine, pyridine, silazane, and sulfide groups.} ^{26. The method of any of the preceding claims, where at least one of the first and second} ^{the functionalizing agent is selected from the group consisting of N,N-} ^{bis(trimethylsilyl)-aminopropylmethyldimethoxysilane, 1-trimethylsilyl-2,2-} ^{dimethoxy-1-aza-2-silacyclopentane, N,N-} ^{bis(trimethylsilyl)aminopropyltrimethoxysilane, N,N-} ^{bis(trimethylsilyl)aminopropyltriethoxysilane, N,N-} b_{is(trimethylsilyl)aminopropylmethyldiethoxysilane, N,N-} _{bis(trimethylsilyl)aminoethyltrimethoxysilane, N,N-} _{bis(trimethylsilyl)aminoethyltriethoxysilane, N,N-} _{bis(trimethylsilyl)aminoethylmethyldimethoxysilane, and N,N-} _{bis(trimethylsilyl)aminoethylmethyldiethoxysilane.} _{27. The method of any of the preceding claims, where the monomer is a conjugated diene} _{monomer and optionally includes a vinyl aromatic monomer.} _{28. The method of any of the preceding claims, where after said step of functionalizing} _{both the first and second reactive ends of the polymer by reacting the first and second} _{reactive ends with first and second functionalizing agents to thereby form a linear} ^{telechelic diene copolymer, a stabilizing agent is introduced to the linear telechelic} ^{diene copolymer.} ^{29. The method of any of the preceding claims, where the stabilizing agent is an aryl} ^silanol. ^{30. The method of any of the preceding claims, where the amount of aryl silanol} ^{introduced is from about 1 to about 7 moles of aryl silanol per mole of lithium} ^{introduced to the polymerization mixture.} ^{31. The method of any of the preceding claims, where the aryl silanol is selected from the} ^{group consisting of triphenylsilanol, diphenylsilanediol, and phenylsilanetriol.} ^{32. The method of any of the preceding claims, where after said step of functionalizing} ^{both the first and second reactive ends of the polymer by reacting the first and second} ^{reactive ends with first and second functionalizing agents to thereby form a linear} t_{elechelic diene copolymer, an aryl silanol and a silane including a hydrolyzable group} _{that forms an acidic species upon hydrolysis is introduced to the linear telechelic} _{diene copolymer.} _{33. The method of any of the preceding claims, where the molar ratio of the aryl silanol} _{to the silane with a hydrolyzable group that forms an acidic species upon hydrolysis} _{is from about 0.5:1 to about 4:1.} _{34. The method of any of the preceding claims, further comprising the step of isolating} _{the linear telechelic polymer from the polymerization mixture.} _{35. A linear telechelic polymer formed by the method of any of the preceding claims.} _{36. A vulcanizable composition of matter including the linear telechelic polymer of any} _{of the preceding claims.}

^{37. A vulcanizate prepared by vulcanizing the vulcanizable composition of matter of any} ^{of the preceding claims.} ^{38. A tire component prepared from the vulcanizable composition of any of the preceding} ^claims. ^{39. A tire tread prepared from the vulcanizable composition of any of the preceding} ^claims. ^{40. The method of any of the preceding claims, where the molar ratio of the aryl silanol} ^{to the silane with a hydrolyzable group that forms an acidic species upon hydrolysis} ^{is from about 0.5:1 to about 4:1.} ^{41. A vulcanizable composition comprising:} (_{i) a linear telechelic diene copolymer prepared by:} _{(a) preparing a dilithium initiator by reacting dialkenyl compound with} _{an alkyl lithium compound;} _{(b) introducing the dilithium initiator, diene monomer, vinyl aromatic} _{monomer, and a randomizer to form a polymerization mixture;} _{(c) allowing the diene monomer and vinyl aromatic monomer to} _{polymerize and form a polymer having first and second reactive} _{ends; and} _{(d) functionalizing both the first and second reactive ends of the} _{polymer by reacting the first and second reactive ends with first and} _{second functionalizing agents to thereby form a linear telechelic} _{diene copolymer;} _{(ii) silica; and} _{(iii) a curative.}

^{42. The vulcanizable composition of any of the preceding claims, further comprising a} ^{silica coupling agent.} ^{43. The vulcanizable composition of any of the preceding claims, further comprising a} ^{silica dispersing agent.} ^{44. The vulcanizable composition of any of the preceding claims, where the silica} ^{dispersing agent is selected from the group consisting of alkyl alkoxysilanes, fatty acid} ^{esters of hydrogenated or non-hydrogenated C5 or C6 sugars, polyoxyethylene} ^{derivatives of fatty acid esters of hydrogenated or non-hydrogenated C5 or C6 sugars,} ^{and esters of polyols, and mixtures thereof.} ^{45. The vulcanizable composition of any of the preceding claims, where the silica} ^{dispersing agent is glycol monostearate.} _{46. The vulcanizable composition of any of the preceding claims, where the silica} _{dispersing agent is a metal glycerolate.} _{47. The vulcanizable composition of any of the preceding claims, where the metal} _{glycerolate is zinc glycerolate.} _{48. The vulcanizable composition of any of the preceding claims, where the vulcanizable} _{composition includes greater than 70 parts by weight silica per 100 parts by weight} _rubber. _{49. The vulcanizable composition of any of the preceding claims, where the vulcanizable} _{composition includes from about 2 to about 30 wt % silica coupling agent based upon} _{the weight of the silica.}

^{50. The vulcanizable composition of any of the preceding claims, where the vulcanizable} ^{composition includes from about 0.1 to about 30 wt % silica dispersing agent based} ^{upon the weight of the silica.} ^{51. A vulcanizate prepared by vulcanizing the vulcanizable composition of matter of any} ^{of the preceding claims.} ^{52. A tire component prepared from the vulcanizable composition of any of the preceding} ^claims. ^{53. A tire tread prepared from the vulcanizable composition of any of the preceding} ^claims. ^{54. A method for forming a vulcanizable composition, the method comprising:} ^{(i) providing a linear telechelic diene copolymer prepared by:} (_{a) preparing a dilithium initiator by reacting dialkenyl compound with} _{an alkyl lithium compound;} _{(b) introducing the dilithium initiator, diene monomer, vinyl aromatic} _{monomer, and a randomizer to form a polymerization mixture;} _{(c) allowing the diene monomer and vinyl aromatic monomer to} _{polymerize and form a polymer having first and second reactive} _{ends; and} _{(d) functionalizing both the first and second reactive ends of the} _{polymer by reacting the first and second reactive ends with first and} _{second functionalizing agents to thereby form a linear telechelic} _{diene copolymer;} _{(ii) providing silica;} _{(iii) providing a curative; and} _{(iv) mixing the linear telechelic diene copolymer, silica, and curative to} _{form the vulcanizable composition.}

^{55. The method of any of the preceding claims, further comprising providing a silica} ^{coupling agent; and further comprising mixing the branched polymer, silica, and silica} ^{coupling agent.} ^{56. The method of any of the preceding claims, further comprising providing a silica} ^{dispersing agent; and further comprising mixing the branched polymer, silica, and} ^{silica dispersing agent.} ^{57. The method of any of the preceding claims, further comprising providing a silica} ^{coupling agent and a silica dispersing agent; and further comprising mixing the linear} ^{telechelic diene copolymer, silica, and silica dispersing agent, and silica coupling} ^agent. _{58. The method of any of the preceding claims, where the silica dispersing agent is} _{selected from the group consisting of alkyl alkoxysilanes, fatty acid esters of} _{hydrogenated or non-hydrogenated C5 or C6 sugars, polyoxyethylene derivatives of} _{fatty acid esters of hydrogenated or non-hydrogenated C5 or C6 sugars, and esters of} _{polyols, and mixtures thereof.} _{59. The method of any of the preceding claims, where the silica dispersing agent is glycol} _{monostearate.} _{60. The method of any of the preceding claims, where the silica dispersing agent is a metal} _glycerolate. _{61. The method of any of the preceding claims, where the metal glycerolate is zinc} _glycerolate.