CN109694453B

CN109694453B - A kind of preparation method of block copolymer and a kind of monovinylarene-isomonoolefin-monovinylarene block copolymer

Info

Publication number: CN109694453B
Application number: CN201710982094.0A
Authority: CN
Inventors: 张雷; 邱迎昕; 周新钦; 龚惠勤; 张月红
Original assignee: Sinopec Beijing Research Institute of Chemical Industry; China Petroleum and Chemical Corp
Current assignee: Sinopec Beijing Research Institute of Chemical Industry; China Petroleum and Chemical Corp
Priority date: 2017-10-20
Filing date: 2017-10-20
Publication date: 2021-08-03
Anticipated expiration: 2037-10-20
Also published as: CN109694453A

Abstract

本发明公开了一种嵌段共聚物及其制备方法，该制备方法包括将异单烯烃与引发剂体系中的各组分在稀释剂中进行第一接触，得到含有聚异单烯烃的中间溶液，所述引发剂体系含有能够提供碳正离子的化合物、四氯化钛、N,N‑二甲基乙酰胺、以及2,6‑二烷基吡啶，第一接触的持续时间为40‑100分钟，将所述中间溶液与单乙烯基芳烃以及可选的补充2,6‑二烷基吡啶进行第二接触，得到含有嵌段共聚物的产物溶液，第二接触的持续时间为80‑110分钟。采用本发明的方法制备嵌段共聚物，不仅能明显提高制备的共聚物中高分子量组分的含量，使得制备的嵌段共聚物具有较高的分子量，同时还显示出较窄的分子量分布；而且制备过程中不会发生凝胶现象。The invention discloses a block copolymer and a preparation method thereof. The preparation method comprises first contacting an isomonoolefin with each component in an initiator system in a diluent to obtain an intermediate solution containing a polyisomonoolefin , the initiator system contains a compound capable of providing carbocation, titanium tetrachloride, N,N-dimethylacetamide, and 2,6-dialkylpyridine, and the duration of the first contact is 40-100 minutes, the intermediate solution is contacted with monovinylarene and optionally supplemented 2,6-dialkylpyridine for a second time to obtain a product solution containing the block copolymer, and the duration of the second contact is 80-110 minute. Using the method of the present invention to prepare the block copolymer can not only significantly increase the content of high molecular weight components in the prepared copolymer, so that the prepared block copolymer has a higher molecular weight, but also shows a narrower molecular weight distribution; and No gelling phenomenon occurs during preparation.

Description

Preparation method of block copolymer and monovinylarene-isomonoolefin-monovinylarene block copolymer

Technical Field

The invention relates to a preparation method of a block copolymer, and also relates to a monovinylarene-isomonoolefin-monovinylarene block copolymer.

Background

The synthesis of thermoplastic elastomers generally involves the preparation of triblock copolymers having rubbery soft blocks and plastic hard blocks. The plastic hard segments are typically vinyl aromatic compounds (e.g., polystyrene), while the rubbery soft segments are typically polybutadiene or polyisoprene. The most predominant styrenic thermoplastic elastomers are styrene-butadiene-styrene triblock copolymers (SBS). The preparation of SBS by using active anion technique is widely used in industry, but the SBS prepared by the technique has many disadvantages: for example, polybutadiene in the soft block structure contains double bonds with high unsaturation, resulting in poor heat resistance, weather resistance and aging resistance of SBS. Although the hydrogenation method can improve the performance of SBS and raise the thermal oxygen stability and use temperature of SBS, the hydrogenation method needs noble metal as catalyst, and the process is complicated and high in cost. In addition, hydrogenation of polybutadiene chain segments tends to form polyethylene chain segments, which lose their original elasticity.

Poly (styrene-isobutylene-styrene) (SIBS) synthesized using living cationic technology overcomes the above disadvantages. Compared with SBS, its advantages are mainly reflected in: (1) the middle rubber soft segment is a fully saturated structure of polyisobutylene, so that the SIBS has more excellent air tightness and thermal oxygen stability; (2) since the lateral methyl groups are closely arranged on both sides of the isobutylene, the SIBS has more excellent shock absorption performance.

CN1982350A discloses a method for synthesizing SIBS triblock copolymers by single-ended initiation: styrene monomer is used as a first monomer, in a polymerization system containing a solvent and an additive, cheap water is used as an initiator, Lewis acid is used as a co-initiator to control cationic polymerization, then isoolefin monomer containing the additive is added to carry out second-stage polymerization to obtain a diblock copolymer, and the first monomer is added to carry out polymerization to obtain the SIBS triblock copolymer.

However, the molecular weight of the SIBS triblock copolymers prepared by this method is still to be further improved.

Disclosure of Invention

The present inventors have found in the course of their research that when a poly (styrene-isobutylene-styrene) is prepared by a living cationic polymerization method, using an initiator system comprising at least one compound capable of providing a carbocation, titanium tetrachloride, N-dimethylacetamide, and 2, 6-dialkylpyridine, and controlling the time for homopolymerization of isobutylene and homopolymerization of styrene, respectively, the block copolymer prepared has significantly increased molecular weight and high molecular weight component content without generating gel. The present invention has been completed based on this finding.

According to a first aspect of the present invention, there is provided a method for preparing a block copolymer, comprising the steps of:

(1) under the condition of cationic polymerization, making isomonoolefin and all the components in the initiator system implement first contact in the diluent to obtain intermediate solution containing polyisomonoolefin, the duration of said first contact is 40-100 min,

the isomonoolefin is selected from the compounds shown in formula I,

in the formula I, R₁And R₂Each is C₁-C₅Linear or branched alkyl of (a); or R₁Is hydrogen, R₂Is C₃-C₅The branched alkyl group of (a) is,

the initiator system comprises at least one compound capable of providing a carbenium ion, titanium tetrachloride, N-dimethylacetamide, and a 2, 6-dialkylpyridine, a compound capable of providing a carbenium ion: titanium tetrachloride: n, N-dimethylacetamide: the molar ratio of the 2, 6-dialkyl pyridine is 1: 10-100: 0.5-10: 0.1-3,

the compound capable of providing a carbenium ion is selected from two hydrogen atoms on an aryl group

Substituted aromatic hydrocarbons, R₃And R₄Each independently is hydrogen, C₁-C₈Alkyl, phenyl, C₇-C₁₀Phenylalkyl of C₇-C₁₀Alkyl phenyl or C₃-C₈X is a halogen group;

the diluent comprises a first diluent and a second diluent, wherein the first diluent is selected from alicyclic alkane, and the second diluent is selected from halogenated alkane;

(2) second contacting said intermediate solution with a monovinylarene and optionally a supplemental 2, 6-dialkylpyridine under cationic polymerization conditions to obtain a product solution containing a block copolymer, said second contacting having a duration of from 80 to 110 minutes.

According to a second aspect of the present invention, there is provided a monovinylarene-isomonoolefin-monovinylarene block copolymer having a molar ratio of structural units derived from an isomonoolefin to structural units derived from a monovinylarene of from 1: 0.05 to 1;

the weight average molecular weight of the block copolymer is 100,000-200,000, and the molecular weight distribution index of the block copolymer is 1.5-3.5;

in the block copolymer, the content of the high molecular weight component is 8 to 20 wt%, and the weight average molecular weight of the high molecular weight component is 200,000-400,000;

the isomonoolefin is selected from the compounds shown in formula I,

in the formula I, R₁And R₂Each is C₁-C₅Linear or branched alkyl of (a); or R₁Is hydrogen, R₂Is C₃-C₅Branched alkyl groups of (a).

The method for preparing the block copolymer can improve the molecular weight of the prepared block copolymer and the content of high molecular weight components, so that the prepared block copolymer has higher molecular weight and shows narrower molecular weight distribution; and no gelation occurs in the preparation process.

Detailed Description

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

The present invention provides a method for producing a block copolymer, comprising the step (1): under the condition of cationic polymerization, the isomonoolefin is firstly contacted with each component in an initiator system in a diluent to obtain an intermediate solution containing the polyisomonoolefin.

The isomonoolefin is selected from the compounds shown in formula I,

In the present invention, C₁-C₅The straight or branched alkyl group of (1) includes C₁-C₅Straight chain alkyl of (2) and C₃-C₅Specific examples thereof may include, but are not limited to: methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, tert-pentyl and neopentyl.

In particular, the mono-olefin may be selected from, but not limited to: 2-methyl-1-propene (i.e., isobutene), 2-methyl-1-butene, 3-methyl-1-butene, 2, 3-dimethyl-1-butene, 2-methyl-1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 2, 3-dimethyl-1-pentene, 2, 4-dimethyl-1-pentene, 2-methyl-1-hexene, 2, 3-dimethyl-1-hexene, 2, 4-dimethyl-1-hexene, 2, 5-dimethyl-1-hexene and 2,4, 4-trimethyl-1-pentene.

Preferably, the monoolefin is isobutylene.

The initiator system contains at least one compound capable of providing a carbenium ion, titanium tetrachloride, N-dimethylacetamide, and a 2, 6-dialkylpyridine.

A substituted aromatic hydrocarbon.

R₃And R₄Each independently is hydrogen, C₁-C₈Alkyl, phenyl, C₇-C₁₀Phenylalkyl of C₇-C₁₀Alkyl phenyl or C₃-C₈A cycloalkyl group of (a).

Said C is₁-C₈Alkyl of (2) includes C₁-C₈Straight chain alkyl of (2) and C₃-C₈Specific examples thereof may include, but are not limited to: methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group, tert-butyl group, n-pentyl group, 2-methylbutyl group, 3-methylbutyl group, 2-dimethylpropyl group, n-hexyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group, 2, 3-dimethylbutyl group, 2-dimethylbutyl group, 3-dimethylbutyl group, 2-ethylbutyl group, n-heptyl group, 2-methylhexyl group, 3-methylhexyl group, 4-methylhexyl group, 5-methylhexyl group, 2-dimethylpentyl group, 2, 3-dimethylpentyl group, 2, 4-dimethylpentyl group, 3-dimethylpentyl group, 3, 4-dimethylpentyl group, 4-dimethylpentyl group, 2-ethylpentyl group, 2-dimethylpentyl group, 3-ethylpentyl group, n-octyl group, 2-methylheptyl group, 3-methylheptyl group, 4-methylheptyl group, 5-methylheptyl group, 6-methylheptyl group, 2-dimethylhexyl group, 2, 3-dimethylhexyl group, 2, 4-dimethylhexyl group, 2, 5-dimethylhexyl group, 3-dimethylhexyl group, 3, 4-dimethylhexyl group, 3, 5-dimethylhexyl group, 4-dimethylhexyl group, 4, 5-dimethylhexyl group5, 5-dimethylhexyl, 2-ethylhexyl, 3-ethylhexyl, 4-ethylhexyl, 2-n-propylpentyl and 2-isopropylpentyl.

Said C is₇-C₁₀Phenylalkyl of (A) means C₁-C₄A group in which one hydrogen atom in the alkyl group is substituted with a phenyl group, and specific examples thereof may include, but are not limited to: benzyl, phenethyl, phenylpropyl (in which propylene may be n-propylene or isopropylene), and phenylbutyl (in which n-butylene may be n-butylene, sec-butylene, isobutylene, or tert-butylene).

Said C is₇-C₁₀The alkylphenyl group of (A) means that one hydrogen atom in the phenyl group is replaced by C₁-C₄Specific examples of the alkyl group substituted group may include, but are not limited to: tolyl group, ethylphenyl group, propylphenyl group (wherein propyl group may be n-propyl group or isopropyl group), and butylphenyl group (wherein butyl group may be n-butyl group, sec-butyl group, isobutyl group, or tert-butyl group).

Said C is₃-C₈Specific examples of the cycloalkyl group of (a) may include, but are not limited to: cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl.

X is a halogen group, such as-F, -Cl, -Br or-I, preferably-Cl or-Br.

Specific examples of the compound capable of providing a carbenium ion may include, but are not limited to: one or more of 1, 4-bis (2-chloroisopropyl) benzene (i.e., p-dicumyl chloride), 1, 4-bis (2-hydroxy-isopropyl) benzene (i.e., p-dicumyl alcohol), and 1, 4-bis (2-methoxy-isopropyl) benzene (i.e., p-dicumyl methyl ether). Preferably, the compound capable of providing a carbenium ion is 1, 4-bis (2-chloroisopropyl) benzene.

The two alkyl groups in the 2, 6-dialkylpyridine may be the same or different and each may be C₁-C₆Alkyl groups of (a) such as: methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, 2-methylbutyl, 3-methylbutyl, 2-dimethylpropyl, n-hexyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 2, 3-dimethylbutyl, 2-dimethylbutyl, 3-dimethylbutylButyl or 2-ethylbutyl. Preferably, the 2, 6-dialkylpyridine is 2, 6-di-tert-butylpyridine and/or 2, 6-dimethylpyridine. From the viewpoint of further increasing the molecular weight of the finally produced block copolymer and the content of high molecular weight components, the 2, 6-dialkylpyridine is more preferably 2, 6-di-tert-butylpyridine.

According to the process of the invention, in the initiator system, the compound capable of providing a carbenium ion: titanium tetrachloride: n, N-dimethylacetamide: the molar ratio of 2, 6-dialkylpyridine may be 1: 10-100: 0.5-10: 0.1-3. Preferably, the compound capable of providing a carbenium ion: titanium tetrachloride: n, N-dimethylacetamide: the molar ratio of the 2, 6-dialkyl pyridine is 1: 20-60: 1-6.5: 0.5-2. More preferably, a compound capable of providing a carbenium ion: titanium tetrachloride: n, N-dimethylacetamide: the molar ratio of the 2, 6-dialkyl pyridine is 1: 23-45: 3-6: 1-1.8.

The first contacting may be carried out by dispersing each component of the initiator system in a solvent, formulating a solution, and adding to a diluent solution comprising the isomonoolefin.

The solvent may be various liquid substances capable of dissolving the compound capable of providing a carbenium ion, titanium tetrachloride, N-dimethylacetamide, and 2, 6-dialkylpyridine. In general, the solvent may be chosen from alkanes, halogenated alkanes and aromatic hydrocarbons, preferably from C₃-C₁₀Alkane, C₁-C₁₀And C₆-C₁₂The aromatic hydrocarbon of (1).

As solvents, the alkanes include aliphatic alkanes and alicyclic alkanes, such as C₃-C₁₀The alkane comprises C₃-C₁₀Aliphatic alkanes and C₃-C₁₀Of an alicyclic alkane.

As solvents, the halogenated alkanes include halogenated aliphatic alkanes and halogenated alicyclic alkanes, such as C₁-C₁₀The halogenated alkane comprises C₁-C₁₀And C₃-C₁₀Of (a) a halogenated alicyclic alkane. The halogen atom in the haloalkane may be chlorine, bromine or fluorine, preferablyIs selected from chlorine or fluorine. The halogenated alkane is preferably C₁-C₄A halogenated aliphatic alkane of (1).

Specific examples of the solvent may include, but are not limited to: propane, n-butane, isobutane, n-pentane, isopentane, neopentane, cyclopentane, n-hexane, 2-methylpentane, 3-methylpentane, 2, 3-dimethylbutane, cyclohexane, methylcyclopentane, n-heptane, 2-methylhexane, 3-methylhexane, 2-ethylpentane, 3-ethylpentane, 2, 3-dimethylpentane, 2, 4-dimethylpentane, n-octane, 2-methylheptane, 3-methylheptane, 4-methylheptane, 2, 3-dimethylhexane, 2, 4-dimethylhexane, 2, 5-dimethylhexane, 3-ethylhexane, 2, 3-trimethylpentane, 2,3, 3-trimethylpentane, 2,4, 4-trimethylpentane, 2-methyl-3-ethylpentane, 2-methylpentane, 3-methylpentane, 2-methylpentane, 3-dimethylpentane, 2-methylpentane, 3-methylpentane, 2-methylpentane, 3-dimethylpentane, 2-methylpentane, 3-methylpentane, 2, 3-methylpentane, 2-methylpentane, 2, 3-methylpentane, 2, 3-methylpentane, 2, and so-methylpentane, 3-methylpentane, 2, 3-methylpentane, 2, 3-methylpentane, 2, 3-methylpentane, 2, n-nonane, 2-methyloctane, 3-methyloctane, 4-methyloctane, 2, 3-dimethylheptane, 2, 4-dimethylheptane, 3-ethylheptane, 4-ethylheptane, 2,3, 4-trimethylhexane, 2,3, 5-trimethylhexane, 2,4, 5-trimethylhexane, 2, 3-trimethylhexane, 2, 4-trimethylhexane, 2, 5-trimethylhexane, 2,3, 3-trimethylhexane, 2,4, 4-trimethylhexane, 2-methyl-3-ethylhexane, 2-methyl-4-ethylhexane, 3-methyl-3-ethylhexane, 3-methyl-4-ethylhexane, 4-methylhexane, 2-dimethylheptane, 2, 3-dimethylheptane, 4-dimethylheptane, 2, 3-dimethylheptane, 2, 4-trimethylhexane, 2, 3-methyl-3-ethylhexane, 4-trimethylhexane, 2-methyl-ethyl-2, 2-ethyl-hexane, 2-ethyl-2, 2-ethyl-hexane, 2-ethyl-hexane, 2, 3-ethyl-3-ethyl-3, 2, 3-ethyl-3, 2, 3-ethyl-3, 3-ethyl-3-4-ethyl-n, 3, 3-diethylpentane, 1-methyl-2-ethylcyclohexane, 1-methyl-3-ethylcyclohexane, 1-methyl-4-ethylcyclohexane, n-propylcyclohexane, isopropylcyclohexane, trimethylcyclohexane (including various isomers of trimethylcyclohexane, such as 1,2, 3-trimethylcyclohexane, 1,2, 4-trimethylcyclohexane, 1,2, 5-trimethylcyclohexane, 1,3, 5-trimethylcyclohexane), n-decane, 2-methylnonane, 3-methylnonane, 4-methylnonane, 5-methylnonane, 2, 3-dimethyloctane, 2, 4-dimethyloctane, 3-ethyloctane, 4-ethyloctane, 2,3, 4-trimethylheptane, 1-methyl-3-ethylcyclohexane, 1-propylcyclohexane, isopropylcyclohexane, trimethylcyclohexane, including various isomers of trimethylcyclohexane, 2,3, 5-trimethylheptane, 2,3, 6-trimethylheptane, 2,4, 5-trimethylheptane, 2,4, 6-trimethylheptane, 2, 3-trimethylheptane, 2, 4-trimethylheptane, 2, 5-trimethylheptane, 2, 6-trimethylheptane, 2,3, 3-trimethylheptane, 2,4, 4-trimethylheptane, 2-methyl-3-ethylheptane, 2-methyl-4-ethylheptane, 2-methyl-5-ethylheptane, 3-methyl-3-ethylheptane, 4-methyl-3-ethylheptane, 5-methyl-3-ethylheptane, 4-methyl-4-ethylheptane, 2-methyl-5-ethylheptane, 4-propylheptane, 3-diethylhexane, 3, 4-diethylhexane, 2-methyl-3, 3-diethylpentane, 1, 2-diethylcyclohexane, 1, 3-diethylcyclohexane, 1, 4-diethylcyclohexane, n-butylcyclohexane, isobutylcyclohexane, tert-butylcyclohexane, tetramethylcyclohexane (including various isomers of tetramethylcyclohexane, such as 1,2,3, 4-tetramethylcyclohexane, 1,2,4, 5-tetramethylcyclohexane, 1,2,3, 5-tetramethylcyclohexane), monofluoromethane, difluoromethane, trifluoromethane, tetrafluorocarbon, monochloromethane, dichloromethane, trichloromethane, carbon tetrachloride, monofluoroethane, difluoroethane, trifluoroethane, tetrafluoroethane, pentafluoroethane, hexachlorocarbon, hexachloroethane, perfluorohexane, 1, 4-diethylcyclohexane, n-butylcyclohexane, isobutylcyclohexane, tert-butylcyclohexane, tetramethylcyclohexane, Monochloroethane, dichloroethane, trichloroethane, tetrachloroethane, pentachloroethane, hexachlorocarbon, monofluoropropane, difluoropropane, trifluoropropane, tetrafluoropropane, pentafluoropropane, hexafluoropropane, heptafluoropropane, octafluoropropane, monochloropropane, dichloropropane, trichloropropane, tetrachloropropane, pentachloropropane, hexachloropropane, heptachloropropane, octachloropropane, monofluorobutane, difluorobutane, trifluorobutane, tetrafluorobutane, pentafluorobutane, hexafluorobutane, heptafluorobutane, octafluorobutane, nonafluorobutane, decafluorobutane, monochlorobutane, dichlorobutane, trichlorobutane, tetrachlorobutane, pentachlorobutane, hexachlorobutane, heptachlorobutane, octachlorobutane, nonachlorobutane, decachlorobutane, toluene, ethylbenzene, and xylenes (including o-xylene, m-xylene, and p-xylene).

Preferably, the solvent is a halogenated alkane. More preferably, the solvent is C₁-C₄Such as methylene chloride.

The amount of the initiator system to be used may be appropriately selected depending on the specific polymerization conditions so as to initiate polymerization. The person skilled in the art is able to determine the amount of initiator sufficient to initiate the polymerization by a limited number of experiments, given the teaching of the prior art.

In step (1), the diluent may be a polymerization solvent capable of dissolving both monoolefin and conjugated diolefin and the resulting block polymer, which is commonly used in the field of cationic polymerization, such as an alkane, a halogenated alkane, or a mixed solvent of an alkane and a halogenated alkane. The alkane may be aliphatic alkane, alicyclic alkane or the mixture of aliphatic alkane and alicyclic alkane.

In a preferred embodiment, the diluent comprises a first diluent and a second diluent, the first diluent being an alicyclic alkane and the second diluent being a halogenated alkane.

The alicyclic alkane is preferably C₃-C₁₀More preferably C₅-C₁₀Of an alicyclic alkane. The halogenated alkane is preferably C₁-C₁₀More preferably C₁-C₄The halogen atom in the halogenated alkane may be chlorine, bromine or fluorine, preferably chlorine or fluorine.

Specific examples of the first diluent may include, but are not limited to: cyclohexane, methylcyclohexane, methylcyclopentane, cyclopentane, 1-methyl-2-ethylcyclohexane, 1-methyl-3-ethylcyclohexane, 1-methyl-4-ethylcyclohexane, n-propylcyclohexane, isopropylcyclohexane, trimethylcyclohexane, 1, 2-dimethylcyclohexane, 1, 3-dimethylcyclohexane, 1, 4-dimethylcyclohexane, 1, 2-diethylcyclohexane, 1, 3-diethylcyclohexane, 1, 4-diethylcyclohexane, n-butylcyclohexane, isobutyl cyclohexane, tert-butylcyclohexane, and tetramethylcyclohexane.

Specific examples of the second diluent may include, but are not limited to: monochloromethane, dichloromethane, trichloromethane, carbon tetrachloride, monofluoroethane, difluoroethane, trifluoroethane, tetrafluoroethane, pentafluoroethane, hexafluorocarbon, monochloroethane, dichloroethane, trichloroethane, tetrachloroethane, pentachloroethane, hexachlorocarbon, monofluoropropane, difluoropropane, trifluoropropane, tetrafluoropropane, pentafluoropropane, hexafluoropropane, heptafluoropropane, octafluoropropane, monochloropropane, dichloropropane, trichloropropane, tetrachloropropane, pentachloropropane, hexachloropropane, heptachloropropane, octachloropropane, monofluorobutane, difluorobutane, trifluorobutane, tetrafluorobutane, pentafluorobutane, hexafluorobutane, heptafluorobutane, octafluorobutane, nonafluorobutane, decafluorobutane, monochlorobutane, dichlorobutane, trichlorobutane, tetrachlorobutane, pentachlorobutane, hexachlorobutane, heptachlorobutane, octachlorobutane, nonachlorobutane and decachlorobutane.

Preferably, the first diluent is methylcyclohexane and the second diluent is methyl chloride.

The amounts of the first diluent and the second diluent in the diluent may be selected according to the specific polymerization conditions. Generally, the first diluent may be present in an amount of from 1 to 80 volume percent, preferably from 20 to 75 volume percent, more preferably from 40 to 65 volume percent, based on the total volume of the diluent; the second diluent may be present in an amount of 20 to 99 volume%, preferably 25 to 80 volume%, more preferably 35 to 60 volume%.

The amount of the diluent may be selected as is conventional in the art. Generally, the diluent is used in an amount such that the total monomer concentration is from 2 to 30% by weight, preferably from 5 to 25% by weight.

According to the block copolymer preparation method of the present invention, the duration of the first contact is 40 to 100 minutes, which can not only obtain polyisomonoolefin with expected molecular weight and make the conversion rate of the isomonoolefin more than 95% (generally 100%), but also make the terminal group of the polyisomonoolefin have higher cation initiation activity, and ensure that the block copolymer with expected molecular weight and composition can still be obtained in the step (2). Preferably, the duration of the first contact is from 50 to 70 minutes.

The method for producing a block copolymer according to the present invention further comprises the step (2): second contacting the intermediate solution with a monovinylarene and optionally a supplemental 2, 6-dialkylpyridine under cationic polymerization conditions to obtain a product solution containing a block copolymer.

According to the preparation method of the present invention, the intermediate solution obtained in step (1) is directly subjected to a second contact with the monovinyl aromatic hydrocarbon and optionally supplemented 2, 6-dialkylpyridine without isolation. That is, after the first contact in step (1) is completed, monovinylarene and optionally supplemented 2, 6-dialkylpyridine are added to the intermediate solution to perform a second contact, and polymerization of monovinylarene is continued on the active end group of the polyisomonoolefin, thereby obtaining poly (monovinylarene-isomonoolefin-monovinylarene).

The monovinylarene is selected from a compound shown as a formula II,

in the formula II, R₅Is C₆-C₂₀Substituted or unsubstituted aryl of (a).

In the present invention, said C₆-C₂₀Examples of the substituted or unsubstituted aryl group of (a) may include, but are not limited to: phenyl, o-tolyl, m-tolyl, p-tolyl, o-ethylphenyl, m-ethylphenyl, p-ethylphenyl, o-tert-butylphenyl, m-tert-butylphenyl, p-dodecylphenyl, 2, 4-di-n-butylphenyl, n-propylphenyl and 2, 4-diethylphenyl.

Preferably, the monovinyl aromatic hydrocarbon is one or more selected from the group consisting of styrene, 2-methylstyrene, 4-tert-butylstyrene, 4-ethylstyrene, 3, 5-diethylstyrene, 3, 5-di-n-butylstyrene, 4-n-propylstyrene and 4-dodecylstyrene.

More preferably, the monovinylarene is one or more selected from styrene, 2-methylstyrene and 4-methylstyrene.

Further preferably, the monovinylarene is styrene.

The amount of monovinylarene used may be selected depending on the composition of the block copolymer. In general, the molar ratio of isomonoolefin to monovinylarene may be from 1: 0.05 to 1, preferably 1: 0.1 to 0.5, more preferably 1: 0.15-0.4.

In step (2), the monovinylarene and the intermediate solution obtained in step (1) may be contacted in the presence of supplemented 2, 6-dialkylpyridine, or may not be contacted in the presence of supplemented 2, 6-dialkylpyridine (i.e., step (2) may not use supplemented 2, 6-dialkylpyridine).

From the viewpoint of further increasing the molecular weight of the finally produced block copolymer and the content of high molecular weight components, the monovinylaromatic hydrocarbon is preferably contacted with the intermediate solution obtained in step (1) in the presence of a supplemental 2, 6-dialkylpyridine. Preferably, the molar ratio of the supplemental 2, 6-di-tert-butylpyridine to monovinylarene is preferably from 0.0005 to 0.005: 1, more preferably 0.0006 to 0.003: 1, more preferably 0.0008 to 0.002: 1. the monovinylarene and the 2, 6-dialkyl pyridine can be prepared into a solution, and the solution is added into the intermediate solution for contact, and the solvent used for preparing the solution containing the monovinylarene and the 2, 6-dialkyl pyridine can be selected from the solvents listed in the preparation of the solution of each component in the initiator system, which are not described in detail herein.

In step (2), the duration of the second contact is 80 to 110 minutes, so that a block copolymer having a higher molecular weight can be obtained without causing gelation. Preferably, the duration of the second contact is 80 to 90 minutes.

According to the method for producing a block copolymer of the present invention, the cationic polymerization conditions in the step (1) and the step (2) may be conventionally selected and are not particularly limited. The first contacting and the second contacting may be conducted at conventional cationic polymerization temperatures. Generally, the first contact and the second contact can each be performed at a temperature in the range of-120 ℃ to 20 ℃, preferably-100 ℃ to 0 ℃, more preferably-100 ℃ to-40 ℃, and further preferably-90 ℃ to-70 ℃. The first and second contacting may be carried out at the same temperature, or at different temperatures, preferably at the same temperature.

According to the block copolymer preparation method of the present invention, in the step (2), after the second contacting is completed, a terminating agent (e.g., alcohol) is further added to the mixture obtained by the second contacting to inactivate the living centers. The type and amount of the terminating agent are not particularly limited in the present invention, and may be selected conventionally in the art, so as to terminate the polymerization reaction, and the details are not repeated herein.

According to the block copolymer production method of the present invention, the solvent and other non-volatile substances in the product solution containing the block copolymer can be removed by a conventional method to obtain the block copolymer.

According to the process of the present invention, the monomers and diluents used for the polymerization are preferably purified before use under conditions commonly used in the art and will not be described herein.

The block copolymer prepared by the method of the invention is a poly (monovinyl aromatic hydrocarbon-isomonoolefin-monovinyl aromatic hydrocarbon) triblock copolymer.

According to a second aspect of the present invention, there is provided a monovinylarene-isomonoolefin-monovinylarene block copolymer (i.e., a poly (monovinylarene-isomonoolefin-monovinylarene) triblock copolymer). The block copolymer contains an isomonoolefin homopolymerization section and monovinylarene homopolymerization sections which are respectively bonded with two ends of the isomonoolefin homopolymerization section, namely: monovinyl aromatic hydrocarbon homopolymerization section-isomonoolefin homopolymerization section-monovinyl aromatic hydrocarbon homopolymerization section.

The isomonoolefin and the monovinylarene are as defined above and will not be described in detail here. Preferably, the isomonoolefin is isobutylene and the monovinylarene is styrene.

According to the block copolymers of the present invention, the molar ratio of structural units derived from an isomonoolefin to structural units derived from a monovinylaromatic hydrocarbon is 1: 0.05 to 1, preferably 1: 0.1 to 0.5, more preferably 1: 0.15-0.4. In the present invention, "structural unit derived from xxx" means that the structural unit is a structural unit formed by addition polymerization of "xxx", for example: the structural unit derived from a monovinylarene refers to a structural unit formed by addition polymerization of a monovinylarene.

The block copolymers according to the invention have a relatively high molecular weight. In general, the weight average molecular weight of the block copolymer according to the present invention may be 100,000-200,000, preferably 110,000-160,000, more preferably 120,000-150,000. The block copolymers according to the invention generally have a molecular weight distribution index of from 1.5 to 3.5, preferably from 1.6 to 3, more preferably from 1.8 to 2.8.

The block copolymer according to the present invention has a high content of the high molecular weight component. Specifically, the content of the high molecular weight component in the block copolymer according to the present invention is 8 to 20% by weight, preferably 9 to 18% by weight, more preferably 10 to 15% by weight. The high molecular weight component means a component having a weight average molecular weight of 200,000 or more. In the block copolymer prepared by the method of the present invention, the weight average molecular weight of the high molecular weight component is generally 200,000-400,000, preferably 250,000-360,000, more preferably 290,000-320,000.

In the present invention, the molecular weight distribution index and the content of the high molecular weight component are measured by Gel Permeation Chromatography (GPC), and narrow-distribution polystyrene is used as a standard.

The block copolymer according to the present invention may be prepared by the process according to the first aspect of the present invention.

The block copolymers according to the invention have a significantly increased molecular weight and a high content of high molecular weight components and are suitable for use as thermoplastic elastomers.

The present invention will be described in detail with reference to examples, but the scope of the present invention is not limited thereto.

The present invention will be described in detail with reference to examples.

In the following examples and comparative examples, the conversion of monomer was measured by a weighing method.

Conversion (%) × (weight of obtained polymer/total weight of added monomers) × 100%; wherein the conversion of isobutylene is obtained after homopolymerization of isobutylene and the conversion of styrene is obtained after homopolymerization of styrene.

In the following examples and comparative examples, the molecular weight of the polymer, the molecular weight distribution index (M)_w/M_n) And the content of high molecular weight component is determined by LC-20A liquid gel permeation chromatograph manufactured by Shimadzu corporation of Japan, and single pore chromatographic column

And

the four columns are used together. The mobile phase is tetrahydrofuran, and the flow rate is 0.7 mL/min; the concentration of the sample solution is 2mg/mL, and the sample injection amount is 200 mu L; the test temperature is 35 ℃; monodispersed polystyrene was used as a standard.

The solvents and monomers used in the following examples and comparative examples were refined by methods commonly used in the art before use, and the polymerization and initiator solutions were prepared in a dry box commercially available from MBRAUN, germany, equipped with a low temperature cold bath.

Examples 1-6 are intended to illustrate the invention.

Example 1

(1) Preparation of initiator solution

0.115g of p-dicumyl chloride (DCC) was dissolved in 20mL of dichloromethane to obtain a DCC solution, 0.2mL of N, N-Dimethylacetamide (DMA) was extracted and dissolved in 20mL of dichloromethane to obtain a DMA solution, 0.2mL of 2, 6-di-tert-butylpyridine (DtBP) was extracted and dissolved in 7.5mL of dichloromethane to obtain a DtBP solution, and the solution was placed in a cold bath at-80 ℃ for future use.

(2) Preparation of isobutene solution

Under the protection of nitrogen, 190mL of methylcyclohexane, 126mL of monochloromethane and 50mL of isobutene were added to a 1000mL three-necked flask, the three-necked flask was placed in a cold bath at-80 ℃, and after stirring for 20 minutes, 16mL of DCC solution, 14.4mL of DMA solution and 3.5mL of DtBP solution were added, and stirring was continued for 10 minutes to obtain an isobutene solution.

Preparation of styrene solution

And (2) uniformly mixing 20mL of styrene, 48mL of methylcyclohexane, 32mL of dichloromethane and 0.9mL of the DtBP solution prepared in the step (1) to obtain a styrene solution.

(3) Polymerisation reaction

Adding 1.2mL of titanium tetrachloride into the isobutene solution at-80 ℃, stirring and reacting at the temperature for 70 minutes (the conversion rate of isobutene is detected to be 100%), adding the styrene solution prepared in the step (2), continuing to stir and react for 80 minutes (the conversion rate of styrene is detected to be 100%), then adding 5g of methanol serving as a terminator into the reaction system, and continuing to stir and react for 5 minutes to obtain a product solution. It was observed that substantially no gel was formed during the polymerization.

Pouring the product solution into a beaker, injecting clean water with the same volume, placing the beaker in a constant-temperature water bath for coagulation at 100 ℃, removing unreacted monomers and solvents, washing the obtained solid substances for three times by using water, naturally drying the solid substances, and finally putting the solid substances into a vacuum oven for drying until the weight is constant, thereby obtaining the poly (styrene-isobutylene-styrene).

The poly (styrene-isobutylene-styrene) thus obtained was subjected to gel permeation chromatography analysis, and it was confirmed that the weight average molecular weight was 134,800, the molecular weight distribution index was 1.86, and the weight average molecular weight of the high molecular weight component was 302,000, the content was 11.8%.

Example 2

A block copolymer was produced in the same manner as in example 1, except that, in the step (3), 1.2mL of titanium tetrachloride was added to the monomer solution, and after the reaction was stirred at that temperature for 100 minutes (the conversion of isobutylene was detected to be 100%), the styrene solution prepared in the step (2) was added, the reaction was continued for 80 minutes (the conversion of styrene was detected to be 100%), then 5g of methanol as a terminator was added to the reaction system, and the reaction was continued for 5 minutes, whereby poly (styrene-isobutylene-styrene) was obtained. It was observed that substantially no gel was formed during the polymerization.

The poly (styrene-isobutylene-styrene) thus obtained was subjected to gel permeation chromatography analysis, and it was confirmed that the weight average molecular weight was 103,000, the molecular weight distribution index was 1.74, and the weight average molecular weight of the high molecular weight component was 284,000, the content was 11.0%.

Comparative example 1

A block copolymer was prepared in the same manner as in example 1, except that, in the step (3), the styrene solution prepared in the step (2) was added and the reaction was continued with stirring for 20 minutes (i.e., the time for homopolymerization of styrene was 20 minutes), thereby obtaining poly (styrene-isobutylene-styrene). The conversion rate of isobutene was 100% and the conversion rate of styrene was 91%. It was observed that substantially no gel was formed during the polymerization.

The poly (styrene-isobutylene-styrene) thus obtained was subjected to gel permeation chromatography analysis, and it was confirmed that the weight average molecular weight was 87,300, the molecular weight distribution index was 1.33, and the weight average molecular weight of the high molecular weight component was 162,000, the content was 4.2%.

Comparative example 2

A block copolymer was prepared in the same manner as in example 1, except that neither an isobutylene solution nor a styrene solution was used to prepare a DtBP solution, thereby obtaining poly (styrene-isobutylene-styrene). The detection proves that the conversion rates of the isobutene and the styrene are both 100 percent. It was observed that substantially no gel was formed during the polymerization.

The poly (styrene-isobutylene-styrene) thus obtained was subjected to gel permeation chromatography analysis, and it was confirmed that the weight average molecular weight was 113,000, the molecular weight distribution index was 2.5, and the weight average molecular weight of the high molecular weight component was 181,000, the content was 3.5%.

Comparative example 3

A block copolymer was prepared in the same manner as in example 1, except that neither the isobutylene solution nor the styrene solution was used to prepare a DMA solution, thereby obtaining poly (styrene-isobutylene-styrene). The detection proves that the conversion rates of the isobutene and the styrene are both 100 percent. It was observed that substantially no gel was formed during the polymerization.

The poly (styrene-isobutylene-styrene) thus obtained was subjected to gel permeation chromatography analysis, and it was confirmed that the weight average molecular weight was 68,400, the molecular weight distribution index was 2.6, and the weight average molecular weight of the high molecular weight component was 101,000, the content was 1.3%.

Comparative example 4

A block copolymer was prepared in the same manner as in example 1, except that the solution of DtBP was not used in preparing the isobutylene solution, thereby obtaining poly (styrene-isobutylene-styrene). The detection proves that the conversion rates of the isobutene and the styrene are both 100 percent. It was observed that substantially no gel was formed during the polymerization.

The poly (styrene-isobutylene-styrene) thus obtained was subjected to gel permeation chromatography analysis, and it was confirmed that the weight average molecular weight was 96,500, the molecular weight distribution index was 1.9, and the weight average molecular weight of the high molecular weight component was 135,000, the content was 3.4%.

Example 3

A block copolymer was prepared in the same manner as in example 1, except that a DtBP solution was not used in preparing a styrene solution, thereby obtaining poly (styrene-isobutylene-styrene). The detection proves that the conversion rates of the isobutene and the styrene are both 100 percent. It was observed that substantially no gel was formed during the polymerization.

The poly (styrene-isobutylene-styrene) thus obtained was subjected to gel permeation chromatography analysis, and it was confirmed that the weight average molecular weight was 105,000, the molecular weight distribution index was 2.03, and the weight average molecular weight of the high molecular weight component was 275,000, the content was 9.6%.

Example 4

A block copolymer was prepared in the same manner as in example 1, except that 2, 6-di-t-butylpyridine was replaced with an equimolar amount of 2, 6-dimethylpyridine, thereby obtaining poly (styrene-isobutylene-styrene). The detection proves that the conversion rates of the isobutene and the styrene are both 100 percent. It was observed that substantially no gel was formed during the polymerization.

The poly (styrene-isobutylene-styrene) thus obtained was subjected to gel permeation chromatography analysis, and it was confirmed that the weight average molecular weight was 131,000, the molecular weight distribution index was 1.95, and the weight average molecular weight of the high molecular weight component was 258,000, the content was 9.6%.

Comparative example 5

A block copolymer was prepared in the same manner as in example 1, except that N, N-dimethylacetamide was replaced with an equimolar amount of diphenylamine, thereby obtaining poly (styrene-isobutylene-styrene). The conversion of isobutylene was found to be 86% and the conversion of styrene was found to be 100%. It was observed that substantially no gel was formed during the polymerization.

The poly (styrene-isobutylene-styrene) thus obtained was subjected to gel permeation chromatography analysis, and it was confirmed that the weight average molecular weight was 104,000, the molecular weight distribution index was 1.76, and the weight average molecular weight of the high molecular weight component was 168,000, the content was 4.6%.

Example 5

(1) Preparation of initiator solution

(2) Preparation of isobutene solution

Under the protection of nitrogen, 190mL of methylcyclohexane, 126mL of monochloromethane and 80mL of isobutene were added to a 1000mL three-necked flask, the three-necked flask was placed in a cold bath at-60 ℃, and after stirring for 20 minutes, 16mL of DCC solution, 18.4mL of DMA solution and 5.5mL of DtBP solution were added, and stirring was continued for 10 minutes to obtain an isobutene solution.

Preparation of styrene solution

And (2) uniformly mixing 20mL of styrene, 48mL of methylcyclohexane, 32mL of dichloromethane and 1.1mL of the DtBP solution prepared in the step (1) to obtain a styrene solution.

(3) Polymerisation reaction

Adding 1.6mL of titanium tetrachloride into the monomer solution at-80 ℃, stirring and reacting for 50 minutes at the temperature (the conversion rate of isobutene is detected to be 100%), adding the styrene solution prepared in the step (2), continuing to stir and react for 90 minutes (the conversion rate of styrene is detected to be 100%), then adding 5g of methanol serving as a terminator into the reaction system, and continuing to stir and react for 5 minutes to obtain a product solution. It was observed that substantially no gel was formed during the polymerization.

The obtained poly (styrene-isobutylene-styrene) was subjected to gel permeation chromatography analysis, and it was determined that the weight average molecular weight was 128,200, the molecular weight distribution index was 2.23, and the weight average molecular weight of the high molecular weight component was 295,000, the content was 14.3%.

Example 6

(1) Preparation of initiator solution

(2) Preparation of isobutene solution

150mL of methylcyclohexane, 166mL of monochloromethane and 80mL of isobutylene were added to a 1000mL three-necked flask under nitrogen protection, the three-necked flask was placed in a cold bath at-60 ℃, and after stirring for 20 minutes, 16mL of DCC solution, 20.1mL of DMA solution and 4.2mL of DtBP solution were added, and stirring was continued for 10 minutes to obtain an isobutylene solution.

Preparation of styrene solution

And (2) uniformly mixing 20mL of styrene, 38mL of methylcyclohexane, 42mL of dichloromethane and 0.7mL of the DtBP solution prepared in the step (1) to obtain a styrene solution.

(3) Polymerisation reaction

Adding 1.8mL of titanium tetrachloride into the isobutene solution at-80 ℃, stirring and reacting for 60 minutes at the temperature (the conversion rate of isobutene is detected to be 100%), adding the styrene solution prepared in the step (2), continuing to stir and react for 80 minutes (the conversion rate of styrene is detected to be 100%), then adding 5g of methanol serving as a terminator into the reaction system, and continuing to stir and react for 5 minutes to obtain a product solution. It was observed that substantially no gel was formed during the polymerization.

The poly (styrene-isobutylene-styrene) thus obtained was subjected to gel permeation chromatography analysis, and it was determined that the weight average molecular weight was 139,200, the molecular weight distribution index was 2.62, and the weight average molecular weight of the high molecular weight component was 305,000, the content was 10.5%.

The results of examples 1-6 demonstrate that poly (styrene-isobutylene-styrene) having a higher molecular weight can be prepared using the method of the present invention, and that the prepared poly (styrene-isobutylene-styrene) has a higher content of high molecular weight components and a narrower molecular weight distribution, while substantially no gel is formed during polymerization.

The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.

Claims

1. a monovinylarene-isomonoolefin-monovinylarene block copolymer, in the block copolymer, the mol ratio of the structural unit derived from isomonoolefin and the structural unit derived from monovinylarene is 1:0.05-1;

In the block copolymer, the content of the high molecular weight component is 8-20% by weight, and the weight average molecular weight of the high molecular weight component is 200,000-400,000;

Described isomonoolefin is selected from the compound shown in formula I,

In formula I, R ₁ and R ₂ are each a C ₁ -C ₅ straight or branched chain alkyl group; or R ₁ is hydrogen, and R ₂ is a C ₃ -C ₅ branched chain alkyl group.

2. The block copolymer according to claim 1, wherein, in the block copolymer, the molar ratio of the structural unit derived from isomonoolefin to the structural unit derived from monovinylarene is 1:0.1-0.5 .

3. The block copolymer according to claim 1, wherein, in the block copolymer, the molar ratio of the structural unit derived from isomonoolefin to the structural unit derived from monovinylarene is 1:0.15-0.4 .

4. The block copolymer of claim 1, wherein the block copolymer has a weight average molecular weight of 110,000-160,000.

5. The block copolymer of claim 1, wherein the block copolymer has a weight average molecular weight of 120,000-150,000.

6. The block copolymer according to any one of claims 1-5, wherein the molecular weight distribution index of the block copolymer is 1.6-3.

7. The block copolymer according to any one of claims 1-5, wherein the molecular weight distribution index of the block copolymer is 1.8-2.8.

8. The block copolymer according to any one of claims 1-5, wherein the content of the high molecular weight component in the block copolymer is 9-18% by weight.

9 . The block copolymer according to claim 1 , wherein, in the block copolymer, the content of the high molecular weight component is 10-15% by weight. 10 .

10. The block copolymer of any one of claims 1-5, wherein the high molecular weight component has a weight average molecular weight of 250,000-360,000.

11. The block copolymer of any one of claims 1-5, wherein the high molecular weight component has a weight average molecular weight of 290,000-320,000.

12. The block copolymer according to any one of claims 1-5, wherein the monovinylarene is selected from the compounds represented by formula II,

In formula II, R ₅ is a C ₆ -C ₂₀ substituted or unsubstituted aryl group.

13. The block copolymer according to any one of claims 1-5, wherein the monovinylarene is selected from the group consisting of styrene, 2-methylstyrene, 4-methylstyrene, 4- tert-Butylstyrene, 4-ethylstyrene, 3,5-diethylstyrene, 3,5-di-n-butylstyrene, 4-n-propylstyrene and 4-dodecylstyrene one or more of them.

14. The block copolymer of any one of claims 1-5, wherein the monovinylarene is styrene.

15. The block copolymer of any one of claims 1-5, wherein the isomonoolefin is isobutylene.

16. a preparation method of the described block copolymer of claim 1, the method comprises the following steps:

(1) Under the conditions of cationic polymerization, the first contact between the isomonoolefin and each component in the initiator system is carried out in the diluent to obtain an intermediate solution containing the polyisomonoolefin, and the duration of the first contact is for 40-100 minutes,

Described isomonoolefin is selected from the compound shown in formula I,

In formula I, R ₁ and R ₂ are each a C ₁ -C ₅ straight-chain or branched alkyl group; or R ₁ is hydrogen, R ₂ is a C ₃ -C ₅ branched chain alkyl group,

The initiator system contains at least one compound capable of providing carbocation, titanium tetrachloride, N,N-dimethylacetamide, and 2,6-dialkylpyridine, and the compound capable of providing carbocation: The molar ratio of titanium tetrachloride:N,N-dimethylacetamide:2,6-dialkylpyridine is 1:10-100:0.5-10:0.1-3,

The compound capable of providing carbocations is selected from the group consisting of two hydrogen atoms on the aryl group.

Substituted aromatic hydrocarbons, _R3 and R4 are each independently hydrogen, _C1 _- _C8 alkyl, phenyl, C7 _- _C10 phenylalkyl, C7 _- _C10 alkylphenyl or C ₃ -C ₈ cycloalkyl, X is a halogen group;

The diluent contains a first diluent and a second diluent, the first diluent is selected from alicyclic alkanes, and the second diluent is selected from halogenated alkanes;

(2) subjecting the intermediate solution to a second contact with monovinylarene and optionally supplemented 2,6-dialkylpyridine under cationic polymerization conditions to obtain a product solution containing a block copolymer, the The duration of the second contact was 80-110 minutes.

17. The method of claim 16, wherein the duration of the first contact is 50-70 minutes.

18. The method of claim 16, wherein the duration of the second contact is 80-90 minutes.

19. The method according to claim 16, wherein the molar ratio of the compound capable of providing carbocation: titanium tetrachloride: N,N-dimethylacetamide:2,6-dialkylpyridine is 1: 20-60: 1-6.5: 0.5-2.

20. The method according to claim 16, wherein the molar ratio of the compound capable of providing carbocation: titanium tetrachloride: N,N-dimethylacetamide:2,6-dialkylpyridine is 1: 23-45:3-6:1-1.8.

21. The method according to claim 16, wherein, in step (2), the second contacting method of the intermediate solution with monovinylarene and optionally supplemented 2,6-dialkylpyridine comprises: A mixed solution containing the monovinylarene and optionally supplemental 2,6-dialkylpyridine is provided, and the intermediate solution is subjected to a second contact with the mixed solution under cationic polymerization conditions.

22. The method according to claim 16 or 21, wherein, in step (2), the second contact is carried out in the presence of supplementary 2,6-dialkylpyridine.

23. The method of claim 22, wherein the molar ratio of the supplemental 2,6-dialkylpyridine to monovinylarene is 0.0005-0.005:1.

24. The method of claim 23, wherein the molar ratio of the supplemental 2,6-dialkylpyridine to monovinylarene is 0.0006-0.003:1.

25. The method of claim 24, wherein the molar ratio of the supplemental 2,6-dialkylpyridine to monovinylarene is 0.0008-0.002:1.

26. The method according to any one of claims 16-21, wherein the 2,6-dialkylpyridine is 2,6-di-tert-butylpyridine and/or 2,6-lutidine .

27. The method of any one of claims 16-21, wherein the 2,6-dialkylpyridine is 2,6-di-tert-butylpyridine.

28. The method of any one of claims 16-21, wherein the compound capable of providing carbocations is 1,4-bis(2-chloroisopropyl)benzene.

29. The method of claim 16, wherein the molar ratio of the isomonoolefin and the monovinylarene is 1:0.05-1.

30. The method of claim 16, wherein the molar ratio of the isomonoolefin and the monovinylarene is 1:0.1-0.5.

31. The method of claim 16, wherein the molar ratio of the isomonoolefin to the monovinylarene is 1:0.15-0.4.

32. The method of any one of claims 16 and 29-31, wherein the isomonoolefin is isobutylene.

33. The method according to any one of claims 16 and 29-31, wherein the monovinylarene is selected from the compounds shown in formula II,

34. The method of any one of claims 16 and 29-31, wherein the monovinylarene is selected from the group consisting of styrene, 2-methylstyrene, 4-methylstyrene, 4-tert. In butylstyrene, 4-ethylstyrene, 3,5-diethylstyrene, 3,5-di-n-butylstyrene, 4-n-propylstyrene and 4-dodecylstyrene one or more of them.

35. The method of any one of claims 16 and 29-31, wherein the monovinylarene is styrene.

36. The method of any one of claims 16-21 and 29-31, wherein the first diluent is methylcyclohexane and the second diluent is monochloromethane.

37. The method according to claim 36, wherein, based on the total amount of the diluent, the content of the first diluent is 1-80% by volume, and the content of the second diluent is 20-80% by volume 99% by volume.

38. The method according to claim 36, wherein, based on the total amount of the diluent, the content of the first diluent is 20-75 vol%, and the content of the second diluent is 25-75 vol% 80% by volume.

39. The method according to claim 36, wherein, based on the total amount of the diluent, the content of the first diluent is 40-65 vol%, and the content of the second diluent is 35-65 vol% 60% by volume.

40. The method of any one of claims 16-21 and 29-31, wherein the first contacting and the second contacting are each performed within a temperature range of -120°C to 20°C.

41. The method of any one of claims 16-21 and 29-31, wherein the first contacting and the second contacting are each performed within a temperature range of -100°C to 0°C.

42. The method of any one of claims 16-21 and 29-31, wherein the first contacting and the second contacting are each performed within a temperature range of -100°C to -40°C.

43. The method of any one of claims 16-21 and 29-31, wherein the first contacting and the second contacting are each performed within a temperature range of -90°C to -70°C.

44. The method of any one of claims 16-21 and 29-31, wherein the first contacting and the second contacting are performed at the same temperature.