MXPA00002008A - Rheology modification of interpolymers of alpha-olefins and vinyl aromatic monomers - Google Patents

Abstract

The invention includes a process of preparing a coupled polymer comprising heating an admixture containing (1) at least one interpolymer of an alpha-olefin and vinyl aromatic monomer and (2) a coupling amount of at least one poly(sulfonyl azide) to at least the decomposition temperature of the poly(sulfonyl azide) for a period sufficient for decomposition of at least 80 weight percent of the poly(sulfonyl azide) and sufficient to result in a coupled polymer. The polymer preferably comprises ethylene, and a vinyl aromatic monomer, preferably styrene. The amount of poly(sulfonyl azide) is preferably from 0.01 to 1 weight percent of the interpolymer and the reaction preferably takes place at a temperature greater than 150°C, more preferably 185°C. The process optionally andin one preferred embodiment additionally comprises steps (b) fabricating an article from the coupled polymer and (c) cross-linking the fabricated coupled polymer. The invention additionally includes any composition produced by a process of the invention and any article made from the composition, preferably articles formed from a melt of the composition, more preferably by blow molding, blowing a film, foaming, or profile extruding, most preferably to form a coating for wire or cable, a tube, a gasket, a seal, roofing, or fiber. The article is optionally calendared. Additionally, the invention includes the use of compositions of the invention as starting materials for forming processes in which the composition is melted and especially in blow molding, blowing a film, foaming, or profile extruding, most preferably to form a coating for wire or cable, a tube, a gasket, a seal, roofing, or fiber.

Description

MODIFICATION OF REOPOLY OF ALPINE-OLEFIN INTERPOLIMERS AND VINYL AROMATIC MONOMERS This invention relates to the coupling of polyolefins, more specifically to the coupling of polyolefins, using insertion in carbon-hydrogen bonds (CH.). As used herein, the term "rheology modification" means the change in the melt viscosity of a polymer, determined by dynamic mechanical spectroscopy, preferably the melt strength is increased while maintaining the high shear viscosity (i.e. viscosity measured at a shear stress of 100 rad / sec by dynamic mechanical spectroscopy) such that a polymer exhibits more resistance to stretching during elongation of the molten polymer in conditions of low shear stress (i.e., the viscosity measured in an effort 0.1 rad / sec cutting by dynamic mechanical spectroscopy), and no sacrificing ifica the production in conditions of high shear. Typically an increase in melt strength is observed when long chain branches or similar structures are introduced into a polymer.

The rheology of polyolefins is often modified using non-selective chemistries that involve free radicals generated, for example, using peroxides or high-energy radiation. However, chemistries that generate free radicals at elevated temperatures also degrade molecular weight, especially in polymers containing tertiary hydrogen, such as copolymers of polystyrene, polypropylene, polyethylene, etc. The reaction of polypropylene with peroxides and pentaerythritol triacrylate is reported by Wang et al. In Journal of Applied Polymer Science, vol. 61, 1395-1404 (1996). They teach that the branching of isotactic polypropylene can be performed by grafting free radicals of di- and tri-vinyl compounds onto polypropylene. However, this approach does not work well in real practice, since the higher rate of chain separation tends to dominate the limited amount of chain coupling that takes place. This occurs because chain separation is an intramolecular process that follows a first order kinetics, while chain coupling is an intermolecular process with a kinetics that is minimally second order. The chain separation results in a lower molecular weight and a higher melt flow rate than would be observed where the branching was not accompanied by separation. Because the separation is not uniform, the molecular weight distribution increases as lower molecular weight polymer chains referred to in the art as "tails" are formed. The teachings of the Patents of the United States of North America Numbers US 3,058,944; 3,336,268; and 3,530,108, include the reaction of certain poly (sulfonylazide) compounds with isotactic polypropylene or other polyolefins, by inserting nitrene into C-H bonds. The product reported in the United States Patent Number US 3,058,944 is cross-linked. The product reported in U.S. Patent Number 3,530,108 is foamed and cured with cycloalkane-di (sulfonylazide) of a given formula. In U.S. Patent Number 3,336,268, the resulting reaction products are referred to as "bridged polymers", because the polymer chains are "bridged" with sulfonamide bridges. The disclosed process includes a mixing step, such as grinding or mixing the sulfonilazide and the polymer in solution or dispersion, then a heating step where the temperature is sufficient to decompose the sulfonyl azide (from 100 ° C to 225 ° C). C, depending on the decomposition temperature of the azide). The starting polypropylene polymer for the claimed process has a molecular weight of at least 275, 000 The blends taught in U.S. Patent No. 3,336,268 have up to 25 percent ethylene-propylene elastomer. U.S. Patent Number 3,631,182 teaches the use of azido format for crosslinking polyolefins. U.S. Patent Number 3,341,418 teaches the use of sulfonyl azide and azido-formate compounds to crosslink thermoplastic materials (PP (polypropylene), PS (polystyrene), PVC (polyvinyl chloride)), and mixtures thereof with rubber (polyisobutene, EPM, etc.) In a similar manner, the teachings of Canadian Patent Number 797,917 (family member of NL 6,503,188) include, the rheology modification using from 0.001 to 0.075 weight percent poly ( sulfonilazide) for modifying the polyethylene of the homopolymer, and blending it with polyisobutylene The U.S. Patent Applications Pending Serial Numbers 08/921641 and 08/921642 both filed on August 27, 1997, disclose the use of peroxides, poly (sulfonilazides), and other reactive materials to crosslink polymers, including interpolymers of vinylidene and alpha-olefin aromatic monomers. It is desirable to modify the rheology of the polymers instead of crosslinking them (ie, having less than 2 percent gel, determined by extraction with xylene, specifically by ASTM 2765). Conveniently, the interpolymers of alpha-olefins and vinylidene aromatic monomers would exhibit a thinning at higher shear stress, comparing with the same polymers not coupled by the practice of the invention. Preferably, a process of the invention would result in a more consistent coupling than coupling methods involving free radicals, ie, the use of the same reagents, amounts, and conditions, would result in consistent amounts of coupling, or changes of consistent (reproducible) properties, especially consistent amounts of gel formation. Preferably, a process would be less subject to the effects of the presence of oxygen than a coupling or modification of rheology involving agents that generate free radicals. Polymers coupled by reaction with coupling agents according to the practice of the invention, conveniently have at least one of these desirable properties, and preferably have desirable combinations of these properties. The invention includes a process for the preparation of a coupled polymer, which comprises heating a mixture containing (1) at least one interpolymer of an alpha-olefin and an aromatic vinylidene monomer, and (2) a coupling amount of when minus one poly (sulfonyl azide) to at least the decomposition temperature of the poly (sulfonyl azide) for a period sufficient for the decomposition of at least 80 weight percent of the poly (sulfonyl azide), and sufficient to result in a polymer coupled. The polymer preferably comprises ethylene and an aromatic vinylidene monomer, preferably styrene. The amount of poly (sulfonyl azide) is preferably 0.01 to 1 weight percent of the interpolymer, and the reaction preferably takes place at a higher temperature than 150 ° C, more preferably at 185 ° C. The process optionally, and a preferred embodiment, further comprises the steps of: (b) making an article from the coupled polymer, and (c) crosslinking the coupled coupled polymer. The invention further includes any composition obtainable by a process of the invention, and any article made from the composition, preferably articles formed from a melt of the composition, more preferably by blow molding, film blowing. , foaming, or profile extrusion, more preferably to form a coating for wires or cables, a tube, a gasket, a seal, roofs, or fibers. The article is optionally passed through calandria. Additionally, the invention includes the use of compositions of the invention as starting materials for the forming processes, wherein the composition melts, and especially in blow molding, film blowing, foaming, or profile extrusion, more preferably to form a coating for wires or cables, pipe, packing, seal, roof, or fiber. The practice of the invention is applicable to any thermoplastic polymer having at least one C-H bond that can react with azide, particularly interpolymers of aromatic vinyl monomers and α-olefins. The interpolymers employed in the present invention include substantially random interpolymers prepared by the polymerization of one or more α-olefin monomers, with one or more vinylidene aromatic monomers, one or more aliphatic or hindered cycloaliphatic vinylidene monomers, and optionally with other monomers ethylenically unsaturated polymerizable. Suitable α-olefin monomers include, for example, α-olefin monomers containing from 2 to 20, preferably from 2 to 12, and more preferably from 2 to 8 carbon atoms. Preferred monomers include ethylene, propylene, butene-1,4-methyl-1-pentene, hexene-1 and octene-1. Ethylene or a combination of ethylene with α-olefins of 2 to 8 carbon atoms is more preferred. These α-olefins do not contain an aromatic fraction. Suitable vinyl aromatic monomers that can be used to prepare the interpolymers employed in the mixtures include, for example, those presented by the following formula: Ar I (CH2) n R? __ C = _ C (R2) 2 wherein Ri is selected from the group of radicals consisting of hydrogen and alkyl radicals containing from 1 to 4 carbon atoms, preferably hydrogen or methyl; each R2 is independently selected from the group of radicals consisting of hydrogen and alkyl radicals containing from 1 to 4 carbon atoms, preferably hydrogen or methyl; Ar is a phenyl group, or a phenyl group substituted with from 1 to 5 substituents selected from the group consisting of halogen, alkyl of 1 to 4 carbon atoms, and haloalkyl of 1 to 4 carbon atoms; and n has a value of from 0 to 6, preferably from 0 to 2, more preferably from 0. The exemplary vinyl aromatic monomers include styrene, vinyltoluene, a-methylstyrene, tertiary butyl styrene, chlorostyrene, including all isomers of these compounds Particularly suitable monomers include styrene and derivatives substituted by lower alkyl or by halogen thereof. Preferred monomers include styrene, α-methylstyrene, styrene derivatives substituted by lower alkyl (from 1 to 4 carbon atoms) or by phenyl ring, such as, for example, ortho-, meta-, and para-methylstyrene, the styrenes halogenated with ring, para-vinyltoluene, or mixtures thereof. A most preferred aromatic vinyl monomer is styrene. The term "hindered aliphatic or cycloaliphatic vinylidene compounds" means addition polymerizable vinylidene monomers corresponding to the formula: A 'Ri _ c = C (R2) 2 wherein Al is a spherically bulky aliphatic or cycloaliphatic substituent of up to 20 carbon atoms, Ri is selected from the group of radicals consisting of hydrogen and alkyl radicals containing from 1 to 4 carbon atoms, preferably hydrogen or methyl; each R2 is independently selected from the group of radicals consisting of hydrogen and alkyl radicals containing from 1 to 4 carbon atoms, preferably hydrogen or methyl; or alternatively, R1 and A1, together form a ring system. The term "spherically bulky" means that the monomer bearing this substituent is usually unable to have addition polymerization by conventional ziegler-Natta polymerization catalysts at a rate comparable to ethylene polymerizations. The preferred aliphatic or cycloaliphatic vinylidene or vinylidene monomers are those in which one of the carbon atoms bearing ethylenic unsaturation is substituted by tertiary or quaternary. Examples of these substituents include cyclic aliphatic groups, such as cyclohexyl, cyclohexenyl, cyclo-octenyl, or substituted by ring alkyl or by aryl thereof, tertiary butyl, norbornyl, and mixtures thereof. The more preferred aliphatic or cycloaliphatic vinylidene or hindered cycloaliphatic compounds are the different isomeric vinyl ring substituted derivatives of cyclohexene and substituted cyclohexenes and 5-ethylidene-2-norbornene. 1-, 3-, and 4-vinylcyclohexene are especially suitable. Other optional polymerizable ethylenically unsaturated monomers include taut ring olefins, such as norbornene and norbornenes substituted by alkyl of 1 to 10 carbon atoms or by aryl of 6 to 10 carbon atoms, with an example interpolymer being ethylene / styrene / norbornene . The number average molecular weight (Mn) of the polymers and interpolymers is usually greater than 5,000, preferably from 20,000 to 1,000,000, more preferably from 50,000 to 500,000. Polymerizations and removal of the unreacted monomer at temperatures higher than the self-polymerization temperature of the respective monomers may result in the formation of some amounts of homopolymer polymerization products, resulting from the polymerization of free radicals. For example, while preparing the substantially random interpolymer, an amount of atactic vinyl aromatic homopolymer can be formed due to the homopolymerization of the aromatic vinyl monomer at elevated temperatures. The presence of the aromatic vinyl homopolymer, in general, is not detrimental to the purposes of the present invention, and can be tolerated. The aromatic vinyl homopolymer can be separated from the interpolymer, if desired, by extraction techniques, such as selective precipitation of the solution with a non-solvent for the interpolymer or vinyl aromatic homopolymer. For the purpose of the present invention, it is preferred that no more than 20 weight percent, preferably less than 15 weight percent, be present based on the total weight of the aromatic vinyl homopolymer interpolymers. The substantially random interpolymers were prepared by polymerizing a mixture of polymerizable onomers in the presence of metallocene or restricted geometry catalysts, for example, as described in European Patent EP-A-0, 416, 815 of James C. Stevens et al. And United States of America Patent No. 5,703,187 by Francis J. Timmers. The preferred operating conditions for these polymerization reactions are pressures from atmospheric to 3,000 atmospheres, and temperatures from -30 ° C to 200 ° C Examples of suitable catalysts and methods for the preparation of substantially random interpolymers are disclosed in the Application for Patent of the United States of America Number 07 / 702,475 filed May 20, 1991, which corresponds to European Patent Number EP-A-514,828; as well as the Patents of the United States of North America Numbers: 5,055,438; ,057,475; 5,096,867; 5,064,802; 5,132,380; 5,189.19.2; ,321,106; 5,347,024; 5,350,723; 5,374,696; 5,399,635; ,470,993; 5,703,187 and 5,721,185.

For purposes of rheology modification or coupling, the polymer is reacted with a polyfunctional compound that may have insertion reactions at the C-H bonds. These polyfunctional compounds have at least 2, preferably 2, functional groups capable of having C-H insertion reactions. Those skilled in the art are familiar with the reactions of C-H insertion, and with the functional groups these reactions may have. For example, carbenes generated from diazo compounds, as cited in Mathur, N.C .; Snow, M.S .; Young, K.M. and Pincock, J.A.; Tetrahedron, (1985), 41 (8), pages 1509-1516, and nitrenes generated from azides, as cited in Abramovitch, R.A. ,; Chellathurai, T .; Holcomb. W.D; McMaster, I.T .; and Vanderpool, D.P .; J. Orcr. Chem., (1977), 42 (17), 2920-6, and Abramovitch, R.A. , Knaus, G.N., J. Pray Chem., (1975), 40 (7), 883-9. Compounds having at least two functional groups that can have C-H insert under the conditions of the reaction, are referred to herein as coupling agents. These coupling agents include alkyl- and aryl-azides (R-N3), acylazides (RC (0) N3), azidoforma-tos (ROC (O) -N3), phosphorylazides ((RO) 2- (PO) -N3 ), phosphinic azides (R2-P (0) -N3) and silylazides (R3-Si-N3).

Polyfunctional compounds that can have insertions in the C-H bonds also include poly (sulfonyl azide) s. The poly (sulfonyl azide) is any compound that has at least two sulfonyl azide groups (-S02N3) that react with the polyolefin. Preferably, the poly (sulfo-nilazide) s have an XRX structure, wherein each X is S02N3 and R represents a hydrocarbyl, hydrocarbyl ether, or silicon-containing, unsubstituted or inertly substituted, group having preferably enough carbon atoms , oxygen, or silicon, preferably carbon, to separate the sulfonylazide groups sufficiently to allow an easy reaction between the polyolefin and the sulfonylazide, more preferably at least 1, most preferably at least 2, and more preferably at least 3 atoms of carbon, oxygen, or silicon, preferably carbon, between the functional groups. Although there is no critical limit for the length of R, each R conveniently has at least 1 carbon or silicon atoms among the X, and preferably has less than 50, more preferably less than 30, and most preferably less than 20 atoms. of carbon, oxygen, or silicon. Within these limits, larger is better for reasons that include thermal stability and shock. When R is straight chain alkyl hydrocarbon, preferably there are less than 4 carbon atoms between the sulfonylazide groups, to reduce the propensity of nitrene to bend and react with itself. Silicon-containing groups include silanes and siloxanes, preferably siloxanes. The term "inertly substituted" refers to substitution with atoms or groups that do not undesirably interfere with the desired reactions or with the desired properties of the resulting coupled polymers. These groups includes fluorine, aliphatic or aromatic ether, siloxane, as well as sulfonylazide groups, when more than two polyolefin chains are to be joined. Suitable structures include R as aryl, alkyl, arylalkyl, arylalkyl, siloxane, or heterocyclic groups, and other groups that are inert and are separated from the sulfonyl azide group, as described. More preferably, R includes at least one aryl group between the sulfonyl groups, more preferably at least two aryl groups (such as when R is 4,4'-diphenyl ether, or 4,4'-biphenyl). When R is an aryl group it is preferred that the group has more than one ring, as in the case of naphthylene bis (sulfonyl azides). The poly (sulfonyl) azides include compounds such as bis (sulfonyl azide) 1,5-pentane, bis (sulfonyl azide) 1,8-octane, bis (sulfonyl azide) 1,10 -decano, bis (sulfonyl azide) 1, 10-Octadecane, l-octyl-2,4,6-benzene tris (sulfonyl azide), bis (sulfonyl azide) 4,4'-diphenyl, 1,6-bis (4'-sulfonazidophenyl) exano, bis (sulfonylazide) ) of 2,7-naphthalene, and mixed sulfonyl azides of chlorinated aliphatic hydrocarbons containing an average of 1 to 8 chlorine atoms, and 2 to 5 sulfonyl azide groups per molecule, and mixtures thereof. The poly (sulfonyl azide) s include oxybis (4-sulfonylazidobenzene), 2,7-naphthalene bis (sulfonylazido), 4, '-bis (sulfonylazido) bi-phenyl, ether bis (sulfonilazide) 4,4' - diphenyl, and bis (4-sulfonylazidophenyl) methane, and mixtures thereof. The sulfonylazides are conveniently prepared by the reaction of sodium azide with the corresponding sulfonyl chloride, although the oxidation of the sulfonyl hydrazines with different reagents (nitrous acid, dinitrogen tetroxide, nitrosonium tetrafluoroborate) has been used. Polyfunctional compounds that can have insertions in the CH bonds also include carbene-forming compounds, such as alkyl- and aryl-hydrazone salts, and diazo compounds, and nitrene-forming compounds, such as alkyl- and aryl-azides ( R-N3), acylazides (RC (0) N3), azidoformates (ROC (O) -N3), sulfonylazides (R-S02- N3), phosphorylazides ((RO) 2- (PO) -N3), phosphinic azides (R2-P (0) - N3), and silylasides (R3-Si-N3). Some of the coupling agents of the invention are preferred because of their propensity to form a greater abundance of carbon-hydrogen insertion products. Compounds such as hydrazone salts, diazo compounds, azido forms, sulfonylazides, phosphorylazides, and silylazides, are preferred, because they form stable singlet electron products (carbenes and nitrenes), which perform ion exchange reactions. carbon-hydrogen efficient, rather than substantially 1) reconfigured by means of mechanisms such as the Curtius-type reconfiguration, as is the case with acylazides and phosphinic azides, or 2) rapidly converted to the triple-state electron configuration Te, which preferably suffers from hydrogen atom abstraction reactions, which is the case with the alkyl- and aryl-azides. Also, it is conveniently possible to select from among the preferred coupling agents, due to the differences in the temperatures at which the different kinds of coupling agents are converted into the active carbene or nitrene products. For example, those skilled in the art will recognize that carbenes are formed from diazo compounds in an efficient manner at temperatures below 100 ° C, while the salts of hydrazones, azido forms, and the sulfonyl azide compounds, react at a rate Suitable at temperatures above 100 ° C, up to temperatures of 200 ° C. (Convenient speeds means that the compounds react at a rate that is fast enough to make commercial processing possible, while reacting slowly enough to allow adequate mixing and composition to result in a final product with the coupling agent properly dispersed and located substantially in the desired position in the final product.This location and dispersion may be different from product to product, depending on the desired properties of the final product). The phosphorylazides can be reacted at temperatures greater than 180 ° C and up to 300 ° C, while the silylazides react preferably at temperatures of 250 ° C to 400 ° C. To modify the rheology, also referred to herein as "coupling", the poly (sulfonyl azide) is used in a rheology modifying amount, i.e., an effective amount to increase the viscosity of low shear (at 0.1 rad / second) of the polymer, preferably at least 5 percent, compared to the polymer of the starting material, but less than a crosslinking amount, i.e., an amount sufficient to result in at least 10 weight percent gel, measured by ASTM D2765-procedure A. Although those skilled in the art will recognize that the amount of azide sufficient to increase the low shear viscosity, and to result in less than 10 weight percent gel, will depend on the molecular weight of the the azide used and the polymer, the amount of preference is less than 5 percent, more preferably less than 2 percent, most preferably less than 1 percent by weight of poly (sulfonyl azide), based on the total weight of the polymer, when the poly (sulfonyl azide) has a molecular weight of 200 to 2,000. To achieve the measurable rheology modification, the amount of poly (sulfonyl azide) is preferably at least 0.01 weight percent, more preferably at least 0.05 weight percent, and most preferably at least 0.10 weight percent. by weight, based on the total polymer. For the rheology modification, the sulfonyl azide is mixed with the polymer, and heated to at least the decomposition temperature of the sulfonyl azide. The decomposition temperature of the azide means the temperature at which the azide becomes the sulfonylnitrene, eliminating nitrogen and heat in the process, determined by differential scanning calorimetry (DSC). The poly (sulfonyl azide) starts to react at a kinetically significant rate (convenient for use in the practice of the invention) at temperatures of 130 ° C, and reacts almost completely at 160 ° C in a differential scanning calorimeter (10 ° scan) C / minute). The ARC (exploration at 2 ° C / hour) shows the establishment of the decomposition at 100 ° C. The degree of the reaction is a function of time and temperature. At the low azide levels used in the practice of the invention, the optimum properties are not reached until the azide reacts in an essentially complete manner. The temperatures for use in the practice of the invention are also determined by the softening or melting temperatures of the polymer starting materials. For these reasons, the temperature is conveniently greater than 90 ° C, preferably greater than 120 ° C, more preferably greater than 150 ° C, and most preferably greater than 180 ° C. Preferred times at the desired decomposition temperatures are times that are sufficient to result in the reaction of the coupling agent with the polymers without undesirable thermal degradation of the polymer matrix. The preferred reaction times in terms of the coupling agent half-life, i.e. the time required for the half of the agent to react at the previously selected temperature, whose half-life can be determined by differential scanning calorimetry, is 5 lives coupling agent stockings. In the case of a bis (sulfonyl azide), for example, the reaction time is preferably at least 4 minutes at 200 ° C. The mixture of the polymer and the coupling agent is conveniently carried out by any means within the skill in the art. The desired distribution is different in many cases, depending on the rheological properties that will be modified. In a homopolymer, it is desirable to have a distribution as homogeneous as possible, preferably to achieve the solubility of the azide in the polymer function. In a mixture, it is desirable to have a low solubility in one or more of the polymer matrices, such that the azide is preferably in one or the other phase, or predominantly in the interfacial region between the two phases. Preferred processes include at least one of: (a) dry blending the coupling agent with the polymer, preferably to form a substantially uniform mixture, and adding this mixture to the melt processing equipment, eg, a melting extruder , to achieve the coupling reaction, at a temperature that is at least the decomposition temperature of the coupling agent; (b) introducing, for example by injection, a coupling agent in liquid form, for example, dissolved in a solvent therefor, or in a paste of the coupling agent in a liquid, in a device containing the polymer, of preference to softened, melted or melted polymer; but in an alternative manner in the form of particles, in solution or dispersion, more preferably in the fusion processing equipment; (c) forming a first mixture of a first quantity of a first polymer and a coupling agent, conveniently a temperature lower than the decomposition temperature of the coupling agent, preferably by melting mixture, and then forming a second mixing the first mixture with a second amount of a second polymer (e.g., a concentrate of a coupling agent mixed with at least one polymer and optionally other additives, which is conveniently mixed in a second polymer or combination thereof optionally with other additives, to modify the second polymers) (d) feed at least one coupling agent, preferably in solid form, more preferably finely ground, for example in powder form, directly to the softened or melted polymer, for example in the melt processing, for example in an extruder; or combinations thereof. Among processes (a) to (d), processes (b) and (c) are preferred, with (c) being more preferred. For example, process (c) is more conveniently used to make a concentrate with a first polymer composition having a lower melting temperature, conveniently at a temperature lower than the decomposition temperature of the coupling agent, and the concentrate is mixed melted in a second polymer composition having a higher melting temperature, to complete the coupling reaction. Concentrates are especially preferred when temperatures are high enough to result in a loss of the coupling agent by evaporation or decomposition, which does not lead to reaction with the polymer, or other conditions that result in that effect. In an alternative way, some coupling occurs during the mixing of the first polymer and the coupling agent, but some of the coupling agent remains unreacted, until the concentrate is mixed in the second polymer composition. Each polymer or polymer composition includes at least one homopolymer, copolymer, terpolymer, or interpolymer, and optionally includes additives within the skill in the art. When the coupling agent is added in a dry form, it is preferred to mix the agent and the polymer in a softened or molten state below the decomposition temperature of the coupling agent, and then heat the resulting mixture to a temperature at least equal at the decomposition temperature of the coupling agent. The term "melt processing" is used to mean any process in which the polymer softens or melts, such as extrusion, granulation, molding, thermoforming, film blowing, composition in the form of the molten polymer, fiber spinning. The polyolefins and the coupling agent are suitably combined in any manner that results in the desired reaction thereof, preferably by mixing the coupling agent with the polymers under conditions that allow sufficient mixing prior to the reaction, to avoid irregular amounts of localized reaction, and then the resulting mixture is subjected to sufficient heat for the reaction. Preferably, a substantially uniform mixture of coupling agent and polymer is formed prior to exposure to the conditions where the chain coupling takes place. A substantially uniform mixture is one in which the distribution of coupling agent in the polymer is sufficiently homogeneous to be evidenced by a polymer having a viscosity after treatment in accordance with the practice of the invention., either higher at a low angular frequency (for example, at 0.1 rad / second), or lower a higher angular frequency (for example, 100 rad / second) than that of the same polymer that has not been treated with the coupling agent, but which has been subjected to the same history of shear and thermal stress. Accordingly, preferably, in the practice of the invention, decomposition of the coupling agent occurs after sufficient mixing to result in a substantially uniform mixture of coupling agent and polymer. This preferred mixture is obtained with the polymer in a molten or melted state, ie, above the crystalline melting temperature, or in a dissolved or finely dispersed condition, instead of being in a solid mass or in a particulate form . The molten or melted form is more preferred, to ensure homogeneity, rather than concentrations located on the surface. Any equipment, preferably equipment that provides sufficient mixing and temperature control in the same equipment, is suitably used, but conveniently, the practice of the invention takes place in devices such as an extruder or a static polymer mixing device, such as a mixer Brabender. The term "extruder" is used in its broadest sense, to include devices such as a device that extrudes granules or a granulator. Conveniently, when there is a melt extrusion step between the production of the polymer and its use, at least one step of the process of the invention takes place in the melt extrusion step. Although it is within the scope of the invention for the reaction to take place in a solvent or in another medium, it is preferred that the reaction be in a bulk phase, to avoid further steps to remove the solvent or other medium. For this purpose, a polymer above the crystalline melting temperature is desirable for a uniform mixture, and to reach a reaction temperature (the decomposition temperature of the sulfonyl azide). In a preferred embodiment, the process of the present invention takes place in a single vessel, that is, the mixture of the coupling agent and the polymer takes place in the same vessel as the heating up to the decomposition temperature of the coupling agent. The container is preferably a twin screw extruder, but is also conveniently a single screw extruder or batch mixer. The reaction vessel more preferably has at least two zones of different temperatures, where the reaction mixture would pass, the first zone conveniently being at a temperature which is at least the crystalline melting temperature or the softening temperature of the polymers, and preferably less than the decomposition temperature of the coupling agents, and the second zone being at a temperature sufficient for the decomposition of the coupling agent. The first zone of preference is at a temperature high enough to soften the polymer and allow it to combine with the coupling agent through the distributive mixture, to a substantially uniform mixture. For polymers having softening points above the decomposition temperature of the coupling agent (preferably greater than 200 ° C), and especially when the incorporation of a polymer with a lower melting point is undesirable (as in a concentrate), the preferred embodiment for incorporating the coupling agent, is the solution mixture of the coupling agent, either in solution or as a mixture in the polymer, to allow the polymer to be imbibed (absorb or adsorb at least some of the coupling), and then the solvent evaporates. After evaporation, the resulting mixture is extruded. The preferred solvent is a solvent for the coupling agent, and more preferably also for the polymer, when the polymer is soluble, such as in the case of polycarbonate. These solvents include polar solvents such as acetone, THF (tetrahydrofuran), and chlorinated hydrocarbons, such as methylene chloride. Alternatively, other non-polar compounds, such as mineral oils, are used, wherein the coupling agent is sufficiently miscible to disperse the coupling agent in a polymer. To avoid the extra step and the resulting cost of re-extrusion, and to ensure that the coupling agent is mixed well in the polymer, in alternative preferred embodiments, it is preferred that the coupling agent be added to the post-reactor area of a polymer processing plant. For example, in a pulp process to produce polyethylene, the coupling agent is added in powder form in liquid form to the polyethylene powder after the solvent is removed by decanting, and before drying and the densification extrusion process. In an alternative embodiment, when preparing polymers, in a gas phase process, the coupling agent is preferably added in powder form in liquid form to the powdered polyethylene before the densification extrusion. In an alternative embodiment, when a polymer is made in a solution process, the coupling agent is preferably added to the polymer solution before the densification extrusion process. The practice of the process of the invention for modifying the rheology of polymers produces modified rheology or chain-coupled polymers, ie, the polymers having sulfonamide, amine, carboxamide tituted by alkyl or tituted by aryl, phosphoramide tituted by alkyl or tituted by aryl, methylene tituted by alkyl, or tituted by aryl, coupling between different chains of the polymer. The resulting compounds conveniently exhibit a higher viscosity with low tear than the original polymer, due to the coupling of the long polymer chains with the base structures of the polymer. The rheology modification leads to polymers that have controlled rheological properties a specifically improved melt strength, as evidenced by a higher viscosity with low shear stress (at 0.1 rad / sec), higher orientation in high shear and high shear processes extension, such as injection molding, film extrusion (blown and emptied), calendering, fiber production, profile extrusion, foams, and insulation of wires and cables. The modified rheology polymers are useful as large blow molded articles, due to the higher viscosity with low shear stress, than the unmodified polymer, and the maintenance of high shear viscosity for processability, as indicated by the high shear viscosity, in the profile extrusion, due to the high melting strength, to avoid the sinking or deformation of the parts that leave the die, measured by the viscosity of low shear, such as blown films for a better bubble stability measured by the viscosity of low shear stress, such as fibers for better spinning potential, as measured by the high shear viscosity, in the insulation of wires and cables for green resistance in order to avoid sinking or the deformation of the polymer on the wire, measured by the viscosity of low shear, which are aspects of the invention. The modified rheology polymers in accordance with the practice of the invention, are superior to the corresponding unmodified polymer starting materials for these applications, due to the viscosity increase, preferably of at least 5 percent in low shear rate (0.1 rad / second), melting strengths high enough to avoid deformation during thermal processing (for example, to avoid subsidence during thermoforming), or to achieve bubble resistance during blow molding, and viscosities of high index of shear stress sufficiently low to facilitate molding and extrusion. These rheological attributes make it possible to more quickly fill the injection molds at high speeds, than the unmodified starting materials, the establishment of foams (stable cellular structure), as indicated by the formation of a lower density closed cell foam. , preferably with higher tensile strength, insulation properties, and compression setting than those obtained in the use of coupling or rheology modification using coupling agents that generate free radicals, due to the high melt viscosity. Conveniently, the hardness and tensile strength of the starting material is maintained. The polymers resulting from the practice of the invention are different from those resulting from the practice of the processes of the prior art, as shown in CA 797,917. The polymers of the present invention are more flexible (lower flexural modulus measured by ASTM D 790-92), and of lower hardness (measured by ASTM D 2240-91) than the linear polyethylene disclosed in the Canadian Patent document Number 797,917. The polymers of the present invention show a better melt elasticity, which is delta tan higher measured by dynamic mechanical spectroscopy, better stretch possibility, ie, higher melt strength measured by the fusion stress, than the unmodified polymer, the counterpart in thermoforming and blow molding of large parts. Especially in the case of the alpha-olefin interpolymers and vinylidene aromatic monomers, there is better thinning of shear (ie, higher) than that exhibited by the starting material. There are many types of molding operations within the skill of the art, which can be used to form useful fabricated articles or parts from the formulations disclosed herein, including different injection molding processes (e.g. described in Modern Plastics Encyclopedia / 89, mid-October 1988 edition, vol 65, No. 11, pp. 264-268, "Introduction to Injection Molding"), and blow molding processes (eg, the one described in Modern Plastics Encyclopedia / 89th edition of mid-October 1988, vol 65, No. 11, pp. 217-218, "(Extrusion-Blo Molding"), profile extrusion, calendering step, pultrusion. The interpolymers of vinyl aromatic monomers and of modified a-olefins, the processes for making them, and the intermediates for making them, of this invention, are useful in the automotive, industrial articles, construction and electrical product (for example, coatings / insulation of wires and cables) and tires. Some of the manufactured items include automotive hoses, single-layer roof, and wire and cable voltage insulation and sleeves. Film and film structures particularly benefit from this invention, and can be made using conventional blown film making techniques, or other biaxial orientation processes, such as store frames, or double bubble processes. Conventional hot blown film processes are described, for example in The Encyclopedia of Chemical Technology, Kirk-Othmer, Third Edition, John Wiley & Sons, New York, 1981, volume 16, pages 416-417, and volume 18, pages 191-192. The biaxial orientation film manufacturing process, as described in a "double bubble" process in U.S. Patent No. 3,456,044 (Pahlke), and the processes described in the U.S. Patent Number 4,352,849 (Mueller), in U.S. Patent Number 4,597,920 (Golike), in U.S. Patent Number 4,820,557 (Warren), in the Patent of the United States of North America Number 4,837,084 (Warren), in U.S. Patent Number 4,865,902 (Golike et al.), In U.S. Patent Number 4,927,708, (Herran et al.), In the U.S. Patent Number 4,952,451 (Mueller), in U.S. Patent Number 4,963,419 (Lustig et al.), And in U.S. Patent Number 5,059,481 (Lustig et al.), Can also be used to make film structures from the novel compositions described herein. The film structures can also be made as a tent frame technique is described, such as is used for oriented polypropylene. Other 83-layer multi-layer film manufacturing techniques for food packaging applications are described in Packaging Foods With Plastics, by Wilmer A. Jenkins, and James P. Harrington (1991), pages 19-27, and in "Coextrusion Basics" by Thomas I. Butler, Film Extrusion Manual; Process, Materials, Properties pages 31-80 (published by TAPPI Press 1992)). The films can be single-layer or multi-layer films. The film made using this invention can also be coextruded with the other layers, or the film can be laminated over other layers in a secondary operation, as described in Packaging Foods With Plastic, by Wilmer A. Jenkins, and James P. Harrington (1991), or that described in "Coextrusion For Barrier Packaging" by WJ Schrenk and C.R. Finch, Societv of Plastics Engineers RETEC Proceedings, June 15-17 (1981), pages 211-229. If a single layer film is produced by means of the tubular film (i.e. blown film techniques), or flat die, (ie, cast film), as described by K.R. Osborn and W.A. Jenkins in "Plástic Films Technology and Packaging Applications" (Technomic Publishing Co., Inc., 1992), then the film must pass through an additional step after extrusion, adhesive lamination or extrusion to other layers of the material of packaging, to form a multilayer structure. If the film is an extrusion of two or more layers (also described by Osborn and Jenkins), the film can still be laminated in additional layers of packaging materials, depending on the other physical requirements of the final film. "Laminations vs. Coextrusion" by D. Dumbleton (Converting Magazine (September 1992)), also discusses the lamination against coextrusion. Single-layer and co-extruded films can also pass through other techniques after extrusion, such as a biaxial orientation process. The extrusion coating is still another technique for producing multilayer film structures using the novel compositions described herein. The novel compositions comprise at least one layer of the film structure. Similar to cast film, extrusion coating is a flat die technique. A sealant can be coated by extrusion on a substrate, either in the form of a single layer or a coextruded extrudate. In general, for a multilayer film structure, the novel compositions described herein comprise at least one layer of the total multilayer film structure. Other layers of the multilayer structure include, but are not limited to, barrier layers, tie layers, structural layers or combinations thereof. Different materials can be used for these layers, some of them being used as more than one layer in the same film structure. Some of these materials include: foil, nylon, ethylene / vinyl alcohol copolymers (EVOH), polyvinylidene chloride (PVDC), polyethylene terephthalate (PET), oriented polypropylene (OPP), ethylene / vinyl acetate copolymers ( EVA), ethylene- / acrylic acid (EAA) copolymers, ethylene / methacrylic acid (EMAA) copolymers, linear low density polyethylene, high density polyethylene, low density polyethylene, nylon, graft adhesive polymers (e.g. grafted polyethylene with maleic anhydride), and paper. In general, multilayer film structures comprise from 2 to 7 layers. The articles from the ethylene interpolymers and a vinyl aromatic monomer, optionally and conveniently are crosslinked subsequently to the configuration (manufacture). Crosslinking prior to fabrication often results in localized gels that inductively introduce defects. "Defects are sometimes visible, or may reduce characteristics such as tensile properties or hardness of the final article, and crosslinking. after the manufacture. Introduced in a step subsequent to manufacture, the network of crosslinked polymer is conveniently distributed in a uniform manner in the resulting article, in such a way that the reduction in tensile properties is minimized. The crosslinking is in the second step, optionally carried out using any element within the experience in this field, for example radiation, including electron beam radiation, or heat. In the case of heat crosslinking, peroxide, azide, and other crosslinking agents are conveniently added before the article is manufactured, and the manufacturing temperature is desirably lower than the decomposition temperature of the crosslinking agent. An element within the experience of this field to achieve a sufficiently low manufacturing temperature, is to add oil to the resin to reduce the viscosity. The crosslinked article conveniently has a lower compression setting, as measured by ASTM D 395-89, than the article prior to crosslinking. These articles optionally, or alternatively, are made by processing an intermediate composition comprising modified rheology interpolymer of the invention, containing unreacted crosslinking agent. The crosslinking agent is optionally included in a composition that includes the poly (sulfonyl azide) before the decomposition temperature of the poly (sulfonyl azide) is reached., or alternatively it is added after the coupling. If the crosslinking agent is added before it reaches the decomposition temperature of the poly (sulfonyl azide), then the crosslinking agent will be insufficiently reactive under the coupling conditions to cause sufficient crosslinking to introduce harmful amounts of localized gels. (Those skilled in the art will recognize that the amounts of gel that are harmful vary with the final article that will be produced). In this case, a crosslinking agent is conveniently activated at a higher temperature, or by different conditions than those found in the coupling. More preferably, the crosslinking agent is added to the coupled elastomer, or the manufactured article is exposed to radiation. In another embodiment, a sufficient amount of poly (sulfonyl azide) is used for coupling and subsequent crosslinking in a composition, and it is exposed to sufficient heat for a sufficient time to couple the interpolymer, but to form less than 2 weight percent of gel: then the composition is manufactured in an article, after which the article is heated to decompose enough poly (sulfonyl azide) to result in crosslinking. Optionally, oils, plasticizers, fillers, colorants, and antioxidants are added to the modified rheology elastomers during the manufacturing process of the article. Examples of the use of modified rheology interpolymers in cross-linked applications include gaskets, wire and cable coatings, roof membranes, foams, weathering, and hoses, where the parts conveniently have a low compression setting temperature and a high service temperature. The modified rheology polymers and intermediates used to make modified rheology polymers can be used alone or in combination with one or more additional polymers in a polymer blend. When additional polymers are present, they can be selected from any of the modified or unmodified homogeneous polymers described above for this invention, and any modified or unmodified heterogeneous polymers, or combinations thereof. The heterogeneous polyethylenes that can be combined with the modified rheology polymers according to this invention fall into two broad categories: those prepared with a free radical initiator at a high temperature and a high pressure, and those prepared with a coordination catalyst at a high temperature and a relatively low pressure. The former are generally known as low density polyethylenes (LDPE) and are characterized by branched chains of polymerized monomeric units pendent from the base structure of the polymer. Low density polyethylene polymers generally have a density between 0.910 and 0.935 grams / cubic centimeter. Polymers and copolymers of ethylene prepared by the use of a coordination catalyst, such as a Ziegler or Phillips catalyst, are generally known as linear polymers, due to the substantial absence of branched chains of the polymerized monomer units suspended from the base structure .

High density polyethylene (HDPE), which generally has a density of 0.941 to 0.965 grams / cubic centimeter, is typically an ethylene homopolymer, and contains relatively few branched chains in relation to the different linear copolymers of ethylene and alpha-olefin . High density polyethylene is well known, commercially available in different grades, and can be used in this invention. Linear copolymers of ethylene and at least one alpha-olefin of 3 to 12 carbon atoms, preferably 4 to 8 carbon atoms, are also well known and commercially available. As is well known in this field, the density of a linear ethylene / cf-olefin copolymer is a function of both the length of the olefin and the amount of the monomer in the copolymer in relation to the amount of ethylene, and the longer the length of the α-olefin and the greater the amount of α-olefin present, the lower the density of the copolymer. Linear low density polyethylene (LLDPE) is typically a copolymer of ethylene and an α-olefin of 3 to 12 carbon atoms, preferably 4 to 8 carbon atoms (for example 1-butene, 1-octene, etc.) , and has sufficient a-olefin content to reduce the density of the copolymer to that of the low density polyethylene. When the copolymer still contains more α-olefin, the density will drop to less than 0.91 grams / cubic centimeter, and these copolymers are known as ultra-low density polyethylene (ULDPE), or very low density polyethylene (VLDPE). The densities of these linear polymers are generally 0.87 to 0.91 grams / cubic centimeter. Materials made both by free radical catalysts and by coordination catalysts are well known in the art, as well as their methods of preparation. The heterogeneous linear ethylene polymers are available from The Dow Chemical Company as Dowlex ™ low density linear polyethylene resins and Attane ™ ultra low density polyethylene. The heterogeneous linear ethylene polymers can be prepared by means of solution, paste, or gas phase polymerization of ethylene and one or more optional α-olefin comonomers in the presence of a Ziegler-Natta catalyst, by processes within the skill of the art, such as are illustrated in U.S. Patent No. 4,076,698 to Anderson et al. Preferably, heterogeneous ethylene polymers are typically characterized by having molecular weight distributions, Mw / Mn, on the scale of 3.5 to 4.1. The relevant discussions of both kinds of materials, and their methods of preparation, are within the skill of the art, as illustrated by those found in U.S. Patent No. 4,950,541, and the patents to which it is assigned. refers.

The following examples are to illustrate this invention, and not to limit it. The proportions, parts, and percentages are by weight, unless otherwise reported. The examples (Ej) of the invention are designated numerically, while the comparative samples (M.C.) are designated alphabetically, and are not examples of the invention.

Test Methods: The viscosity of the polymer was measured as a function of the shear rate, according to the following method. A dynamic mechanical spectrometer, commercially available from Rheometrics, Inc. under the trade designation RMS-800, with parallel plates of 25 millimeters in diameter, was used to determine the dynamic rheological data. A frequency sweep was carried out with 5 logarithmically separated points from 0.1 to 100 rad / second at 190 ° C. The tension was determined within the linear discoelastic regime, performing a voltage sweep at 0.1 rad / second at 190 ° C, by sweeping voltage from 2 to 30 percent tension in steps of 2 percent, to determine the voltage minimum required to produce torques within the transducer specification; Another voltage sweep at 100 rad / second at 190 ° C was used to determine the maximum stress before the lack of linearity was presented according to the procedure disclosed by J.M. Dealy and K.F. Wissbrun, "Melt Rheology and Its Role in Plastics Processing", Van Nostrand, New York (1990). The entire test was performed on a nitrogen purge to minimize oxidative degradation. The storage module (G ') (which is included in Table 5) was measured according to the following method. A dynamic mechanical spectrometer commercially available from Rheometrics Inc, under the trade designation RDA-II, was used to obtain dynamic mechanical spectrometry data. A temperature sweep was run from about -70 ° C to 300 ° C, at 5 ° C / step, with an equilibrium delay of 30 seconds in each step. The oscillation frequency was one radian / second, with a self-tension function of 0.1 percent initially, increasing in positive adjustments of 100 percent whenever the torque decreased to 4 grams-centimeter. The maximum tension was set at 26 percent. Accessories of parallel plates of 7.9 millimeters were used, with an initial gap of 1.5 millimeters at 160 ° C (the sample was inserted in the RDA-II at 160 ° C). The "holding" function was coupled at 160 ° C, and the instrument was cooled to -70 ° C, and the test was started. (The sustain function corrects thermal expansion or contraction, as the test chamber heats or cools). A nitrogen environment was maintained throughout the experiment, to minimize oxidative degradation. A thermomechanical analyte (TMA) commercially available from Perkin Elmer Corporation, under the commercial designation of model TMA 7, was used to measure the upper service temperature (UST). A probe strength of 102 grams, and a heating rate of 5 ° C / minute was used. Each test sample was a disk with a thickness of 2 millimeters in diameter, prepared by compression molding at 205 ° C, and cooling with air at ambient temperature. Extraction with xylene was performed to determine the gel content, weighing samples of one gram of polymer. The samples are transferred to a mesh basket, which is then placed in boiling xylene for 12 hours. After 12 hours, the sample baskets are removed and placed in a vacuum oven at 150 ° C, and in a vacuum of 71.12 centimeters of Hg for 12 hours. After 12 hours, the samples are removed, allowed to cool to room temperature for a period of 1 hour, and then weighed. The results are reported as the percentage of the polymer extracted. Percentage extracted = (initial weight-final weight) / initial weight according to ASTM D-2765 - Procedure "A". The tensile properties were determined by compression molding of 1.5875 millimeter plates. Traction samples were then cut from these plates, and tested in an instrument commercially available from Instron Corporation, under the commercial designation Instron Model 1122 load frame, using 0.870-inch (2.2-centimeter) micro-traction samples, measured at an extension speed of 5 inches / minute (12.7 centimeters / minute). The tensile to breaking and elongation to break was measured according to ASTM D-412. The hardness was measured as the area below the tension / tensile curve. The melt index was measured in accordance with ASTM D-1238, condition 190 ° C / 2.16 kilograms (formerly known as Condition E). Melt strength of Gottfert or Rheoten was measured using a capillary rheometer commercially available from Instron Corporation under the commercial designation of Instron Capillar Model 3211, coupled with a melt strength tester commercially available from Gottfert Inc. under the trade designation Gottfert Rheotens. A capillary rheometer is used to deliver a polymer melt through a die, at a constant production speed. The melt strength tester is used to uniaxially stretch the molten polymer filament using tightening rollers. The required tensile force is recorded as a function of the winding speed of the clamping rollers of the fusion resistance tester. The maximum tensile force achieved during the test is defined as the resistance to fusion. In the case of the molten polymer exhibiting stretch rosonance, the tensile force before the establishment of the stretch resonance was taken as the melt strength. The force values were not corrected for the weight of the extrudate that hung between the clamping rollers and the lower plate.

Table 1 Conditions for the measurement of the Rheotens melt strength.

MI is the melt index measured in grams / 10 minutes.

All instruments were used according to the manufacturer's instructions.

Examples: The interpolymers of alpha-olefins and vinyl aromatic polymers used in the examples are also referred to herein as ethylene-styrene interpolymers (ESI), and were synthesized according to the following general procedure: Reactor description.

A 6 gallon (22.7 liter) autoclave continuously stirred tank reactor (CSTR), jacketed in oil, was used as the reactor. A magnetically coupled agitator, with propellers commercially available from Lightning Mixers, Inc., under the commercial designation of propellers A-320, provides the mixture. The reactor worked full of liquid at 475 psig (3,275 kPa). The process flow was in the background and out of the top. A heat transfer oil was circulated through the reactor jacket to remove some heat from the reaction. After the exit from the reactor, there was a flow meter that measured the flow and density of the solution. All lines at the reactor outlet were steam tracked at 50 psi (344.7 kPa) and isolated.

Process . Solvent (ethylbenzene for ESI-1 and ESI-2, and toluene for ESI-3 and ESI-4) was supplied to the reactor at 30 psig (207 kPa). The feed to the reactor was measured by a mass flow meter. A variable speed diaphragm pump controlled the solvent feed rate. At the discharge of the solvent pump, a side stream was taken to provide flood flows for the catalyst injection line (1 pound / hour (0.45 kilogram / hour)), and the reactor agitator (0.75 pounds / hour ( 0.34 kilograms / hour)). These flows were measured by differential pressure flow meters, and controlled by manually adjusting the microflow needle valves. Uninhibited styrene monomer was supplied to the psig reactor (308 kPa). The feed to the reactor was measured by a mass flow meter. A variable speed diaphragm pump controlled the feeding speed. The styrene stream was mixed with the remaining solvent stream. Ethylene was supplied to the reactor at 600 psig (4,238 kPa). The ethylene stream was measured by a mass flow meter just before a valve that controlled the flow. A flow meter controller was used to deliver hydrogen to the ethylene stream at the outlet of the ethylene control valve. The ethylene / hydrogen mixture is combined with the solvent / styrene stream at room temperature. The temperature of the solvent / monomer, when it entered the reactor, was reduced to 5 ° C by means of a heat exchanger with glycol at -5 ° C on the jacket of the same. This solvent / styrene stream entered the bottom of the reactor. The three component catalyst system described in Table 2, and its solvent flood, also enter the reactor at the bottom, but through a gate different from the monomer stream. The preparation of the catalyst components took place in a box with handling gloves, inert atmosphere. The diluted components were placed in nitrogen-filled cylinders and loaded into the catalyst tanks for the reaction. From these working tanks, the catalyst was pressurized with piston pumps, and the flow was measured with flow meters. These streams combine with each other, and with the catalyst flooding solvent, just before entering through a single injection line into the reactor, where they react to form the designated polymers. Polymerization was stopped when the reaction mixture flowed into a reactor product line, after the reactor, by the addition of catalyst annihilator (water mixed with solvent) to the product line of the reactor., after a flow meter that measures the density of the solution. A static mixer in the line provided the dispersion of the catalyst annihilator and the additives in the effluent stream of the reactor. This current then entered the heaters after the reactor, which provide additional energy for the evaporation of solvent removal. This evaporation occurred when the effluent exited the heater after the reactor, and the low pressure from 475 psig (3,275 kPa) to approximately 250 mm Hg (33 kPa) of absolute pressure in the pressure control valve of the reactor. This evaporated polymer entered a devolatilizer jacketed in hot oil. About 85 percent of the volatile compounds were removed (hereinafter referred to as volatiles) of the polymer in the devolatilizer. The volatiles came out through the top of the devolatilizer. The output volatile stream was condensed with a glycol-encased exchanger, entered the suction of a vacuum pump, and discharged to a glycol-encased solvent and styrene / ethylene separation solvent container. The solvent and styrene were removed from the bottom of the container, and the ethylene from the top. The ethylene stream was measured with a flow meter, and analyzed to determine its composition. The measurement of the ventilated ethylene plus a calculation of the gases dissolved in the solvent / styrene stream were used to calculate the ethylene conversion. The polymer separated in the devolatilizer was pumped out with a gear pump, into a striker commercially available from Werner Pfleiderer Corporation, under the trade designation of ZSK-30 devolatilizing vacuum extruder. The dried polymer came out of the extruder as a single strand. This strand cooled as it was pulled through a water bath. The excess water was blown from the strand with air, and the strand was crushed into granules with a strand crusher. The catalyst used in the preparation of ESI-1 and ESI-2 was (tertiary butyl-amido) dimethyl (tetramethylcyclopentadienyl) silane-titanium (II) -1,3-pentadiene. The catalyst used in the preparation of ESI-3 and ESI-4 was titanium, [1, 1 '- (? 4-l, 3-butadiene-1,4-diyl) -bis [benzene]] [1- [( 1, 2, 3, 3a, -llb-h) -IH-cyclopenta [1] phenanthren-1-yl] -N- (1,1-dimethylethyl) -1, 1-dimethylsilanaminate (2-) -kN]. The cocatalyst was tetrais (pentafluorophenyl) borate ammonium seboalkyl bishydrogenated. A commercially modified methylaluminoxane available from Akzo Nobel under the trade designation MMA0-3A was also used, in the amounts indicated in Tables 2a and 2b, and is referred to herein as MMAO.

Table 2a. Proportion of Catalyst to Cocatalyst, and Proportion of MMAO to Catalyst Table 2b: Catalyst and cocatalyst used in ESI-3 and ESI-4 (units in the United States). where Cat is the catalyst, and CoCat is the cocatalyst, both identified above, conc. It is concentration.

Table 2b (Table 2a in units of the International System) Table 3 Reactor Data SCCM stands for standard cubic centimeter.

Example 1 v Comparative Sample A: Poly (sulfonyl azides) used for ESI coupling A commercially available mixer was used in C.W. Brabender Instruments Inc., consisting of a measuring head (Type R.E.E No. A-19 / S.B) and a temperature control console (Type SP-2003, No. 1382). The mixer was heated to 180 ° C. The paddles were rotated at 60 revolutions per minute, and 50 grams of ESI-1 (26 weight percent styrene interpolymer (the remainder comonomer of ethylene), 6 weight percent atactic polystyrene, was added. MI of 1.0 (melt index)) prepared as illustrated above, to the recipient. After 2 minutes of mixing, 0.1 grams (0.26 mmol, 0.2 weight percent) of 4,4'-disulfonylazidophenyl ether was slowly splashed into the vessel. The speed of the blades was increased to 80 revolutions per minute, and the polymer was mixed for 5 minutes. During the mixing period, the viscosity and elasticity of the polymer melt were increased. The mixer vessel was removed, and the polymer was scraped off the paddles and the container, to give the polymer of Example 1. For Comparative Sample A, the properties of the gel content on the ESI-1 sample were measured without modification.

Table 4 Table 5 Table 6 The results of Example 1 show that sulfonyl azide can be used to modify the rheology of vinyl aromatic interpolymers. The increase in storage module G 'at a high temperature (100-200 ° C) indicates that the coupling reaction occurs. The gel content data shows that the modified ESI does not reticle.

Example 2 and Comparative Sample B: Coupling of ESI of High Styrene Content (Percent by weight of styrene = 73 percent). A mixer commercially available from Haake Fusion Co. consisting of a HaakeBuchler Rheomix 6Q0 mixer with roller ethyl blades was connected to a HaakeBuchler Rheocord 9000 torque rheometer. The mixing vessel was heated to 170 ° C. An ESI-2 polymer sample (having a melt index of 30.0 grams / 10 minutes, and 75 weight percent of an ethylene-styrene interpolymer containing 73.2 weight percent styrene comonomer was charged the rest ethylene monomer) and 25.0 weight percent atactic polystyrene)), in the mixing vessel. After 1 minute, 0.12 grams of 1,3-disulfonylazidobenzene (0.3 weight percent) was added to the mixer. Over a period of 3 minutes, the torque increased from 150 m-g to 350 m-g. After 10 minutes, the sample was removed from the Haake container, to give Example 2. The melt index and the upper surface temperature (TMA) were measured. Comparative Sample B was a sample of the untreated starting material.

Table 7 The results of Example 2 show that sulfonyl azide can be used to modify the rheology of vinyl aromatic interpolymers as ESI, with a high styrene content. Examples 3-7 and Comparative Samples C-F: Description of materials: The materials of Examples 3-12 and Corresponding Comparative Samples designated by underlined codes are as follows: Polyethylene LDPE 620 1: Low density polyethylene (LDPE) (12 of 1.85 grams / 10 minutes, density of 0.9239 grams / cubic meter) commercially available from The Dow Chemical Company under the commercial designation of polyethylene LDPE 620 I.

Nordel 2722 hydrocarbon rubber: An ethylene (72 weight percent) propylene (22 weight percent) ethylidene norbornene (6 weight percent), with a specific gravity of 0.87, at 22.4 ° C, a Mw / Mn = 3.65, and one Mw = 115,200, a Mooney viscosity of 20, commercially available from DuPont Dow Elasto-mers LCC, under the trade designation of Nordel 2722 hydrocarbon rubber. BSA: 4,4'-oxybis (benzenesulfonyl azide) CAS # [7456-68-0]. The bis (sulfonyl azide) was prepared by the reaction of sodium azide with the corresponding bis (sulfonyl chloride). Bis (sulfonyl chloride) is commercially available. The solid sodium azide was added to the corresponding acetone solution of the bis (sulfonyl chloride).

Control Sample C: A sample of 0.400 kilograms of polyethylene LDPE 620 I granules, defined above, was extruded in a twin-screw extruder with a screw diameter of 18 millimeters, commercially available from Haake Inc. under the trade designation of microstrip Haake 18, which has 5 zones, each one separated from the other by 10 centimeters, and each zone having a thermocouple (inserted in the metal) to measure the temperature in it, using the following conditions: Screw speed: 100 revolutions per minute; Torque Torque of 5,300 milligrams; Pressure of 870 psi (6,000 kPa), temperature: 150 ° C, 175 ° C, 201 ° C, 224 ° C, 225 ° C, and 214 ° C for zones 1, 2, 3, 4, 5, and the given output, respectively.

Control Sample D: The rheological properties of Control Sample D (Table 8) were measured on commercially available Nordel 2722 hydrocarbon rubber, described above, without modifi cation.

Control Sample E: A sample of 0.4 kilograms of ESI-3 granules (having 31.3 weight percent styrene and 68.7 weight percent ethylene in the copolymer, 1 weight percent atactic polystyrene and a melt index of 0.98 grams / 10 minutes), was extruded using the same extruder conditions used in Comparative Sample C.

Comparative Sample F: A sample of 0.4 kilograms of ESI-4 granules (70 weight percent styrene, 30 weight percent ethylene in the copolymer, and 4.6 weight percent atactic polystyrene, melt index 1.36) grams / 10 minutes) was extruded using the same extruder conditions used in Comparative Sample C.

Example 3: A solution of 5 percent by weight of BSA in tetrahydrofuran (THF) was prepared. The BSA solution (4 grams) was added to 400 grams of ESI-3 (which has 31.3 weight percent styrene and 68.7 weight percent ethylene in the copolymer 1 weight percent atactic polystyrene, and a melt index of 0.98 grams / 10 minutes), in granules, in a 1-gallon polyethylene bag. The bag was shaken to disperse the BSA uniformly over the granules. The bag was opened and placed in a hood for 2 hours, to allow the acetone to evaporate, to form a formulated resin. The formulated resin was extruded using the same extruder and the extrusion conditions that were used in Control Sample C. The results of the viscosity tests, the melting properties, and the gel content are in Tables 8, 9, and 10 respectively. Exes 4 and 5: The procedure of Example 3 was repeated, with the exception that the amounts of BSA mentioned in Table 8 were used.

Examples 6 and 7: The procedure of Example 3 was repeated, with the exception that the amounts of BSA mentioned in Table 8 were used, and an ethylene-styrene polymer with 70 weight percent of styrene incorporated therein. , previously designated as ESI-4.

Table 8. Effect of Viscosity Coupling Table 9. Effect of the Coupling on the Resistance to Fusion, on the Fusion Index, and on the Molecular Weight of the Interpolymers.

The results of Table 9 indicate that the Gottfert melt strengths of the samples treated (coupled) with poly (sulfonyl azide) were higher than those of the untreated samples of the same polymer. High melt strength is desirable for many applications, such as foaming, wire rope, and profile extrusion.

Control Sample C (Table 8) illustrates the viscosity behavior of polyethylene LDPE 620 I, a state-of-the-art material for foam applications. Control Sample D (Table 8) illustrates the viscosity behavior of Nordel 2722 hydrocarbon rubber (EPDM, ethylene-propylene-diene terpolymer), a state-of-the-art material for wire rope coating applications . The polyethylene LDPE 620 I and the hydrocarbon rubber Nordel 2722 have a higher melt strength than the unmodified interpolymers of vinylidene aromatic monomers and alpha-olefins, as illustrated herein by Comparative Samples C.S. E and C.S. F. The melt strength was measured as the Gottfert melt strength, or the low shear viscosity ratio (0.1 Rad / sec) up to the high shear stress (100 Rad / sec). Both the polyethylene LDPE 620 I (Comparative Sample C) and the hydrocarbon rubber Nordel 2722 (Comparative Sample D) have a higher proportion of viscosity from low to high shear than untreated interpolymer samples (Comparative Sample E and Comparative Sample) F). The treatment with azide significantly increases the viscosity at a low shear rate (0.1 rad / sec), and the ratio of low viscosity and high shear stress. The results of Table 8 show that azide can be used to modify the rheology of interpolymers, to achieve a low to high shear viscosity of low density polyethylene or Nordel 2722 hydrocarbon rubber. The amount of azide used depends on the styrene content of the interpolymer, and the degree of rheology modification required for different applications.

Table 10. Effects of Azide on the Gel Content of the ESI Samples.

The interpolymer samples treated with azide have gel contents comparable to the untreated samples (Comparative Samples E and F). The results of Tables 8, 9, and 10, show that interpolymers with a desirable melt strength can be modified in their rheology using poly (sulfonyl azide). The amount of azide can be selected to avoid excessive gel formation which can cause detrimental effects on the mechanical properties, such as the elongation and hardness of the manufactured parts.

Claims (10)

1. A process for the preparation of a coupled polymer, characterized by a step of heating a mixture containing: (1) at least one interpolymer of an α-olefin and a vinyl aromatic monomer, and (2) a coupling amount of when minus one poly (sulfonyl azide), at least the decomposition temperature of the poly (sulfonyl azide) for a period sufficient for the decomposition of at least 80 weight percent of the poly (sulfonyl azide), and sufficient to result in a coupled polymer wherein the coupled polymer has a viscosity of low shear stress at 0.1 rad / sec at least 5% higher than the polymer of the starting material; and less than 2% by weight gel as measured by ASTM D2765-procedure A.

2. The process of claim 1, wherein the interpolymer comprises ethylene, and an aromatic vinyl monomer; the amount of poly (sulfonyl azide) is 0.01 to 1 weight percent of the interpolymer; and the poly (sulfonyl azide) and the elastomer, react at a temperature which is at least the decomposition temperature, and greater than 185 ° C.

The process of claim 1 or 2, wherein the coupling agent comprises at least one poly (sul-fonilazide) having an X-R-X structure wherein each X is S02N3, and R represents a hydrocarbyl, hydrocarbyl ether, or silicon-containing, unsubstituted or inertly substituted group; at least one poly (sulfonyl azide) has at least 3, but less than 50 carbon atoms, silicon, or oxygen between the sulfonylazide groups; and R includes at least one aryl group between the sulfonyl groups.

The process of any of claims 1 to 3, wherein the poly (sulfonyl) azide is selected from 1-pentane bis (sulfonylazide), 1,8-octane bis (sulfonyl azide) of 1,10-decane, 1, 10-octadecane bis (sulfonylazide), l-octyl-2,4,6-benzene tris (sulfonilazide), 4,4'-diphenyl ether, bis (sulfonyl azide), 1,6-bis (4 '-) sulfonazidophenyl) hexane, 2,7-naphthalene bis (sulfonyl azide), mixed sulfonyl azides of aliphatic hydrocarbons containing an average of 1 to 8 chlorine atoms, and 2 to 5 sulfonyl azide groups per molecule, and mixtures thereof.

The process of any of claims 1 to 4, which further comprises the steps of (b) making an article from the coupled polymer, and (c) crosslinking the coupled coupled polymer.

6. A composition obtainable as the reaction product of any of the processes of claims 1 to 5.

7. An article comprising a composition of claim 6.

8. The process for forming the article of claim 7, by blow molding, film blowing, foaming, or profile extrusion, of a composition of claim 6.

9. The article of claim 7, which is a coating for wires or cables, a tube, a gasket, a seal, a roof, or a fiber. The use of a composition of claim 6, as a starting material for blow molding, film blowing, foaming, or profile extrusion.