Grafted copolymer of polyisobutene and polyisoprene and preparation method thereof

Abstract

The invention relates to the field of grafted copolymers, and provides a grafted copolymer of polyisobutene and polyisoprene and a preparation method thereof. According to the grafted copolymer, isocrotyl polymer chain segments are adopted as a main chain, polyisoprene chain segments are adopted as a branch chain, and the main chain and the branch chain are bonded in a grafted mode. The absolute weight-average molecular weight Mw of the grafted copolymer ranges from 200 kg / mol to 3000 kg / mol, and the polydispersity index ranges from 1.3 to 4.0. On the basis that the total mass of the grafted copolymer is 100%, the mass content of polyisoprene chain segments ranges from 3% to 40%; the absolute weight-average molecular weight of the isocrotyl polymer chain segments as the main chain ranges from 100 kg / mol to 2000 kg / mol. By means of the method, grafted copolymer materials with different branch chain numbers and branch chain lengths are synthesized, and the problems that in isoprene cationic polymerization, the polymer molecular weight is low, and cyclizing isomerization is serious are effectively solved.

Description

technical field

[0001] The invention relates to the field of graft copolymers, in particular to a graft copolymer of polyisobutylene and polyisoprene and a preparation method thereof. Background technique

[0002] Cationic polymerization or cationic polymerization is one of the important components of polymer synthesis chemistry. There are also various types of monomers that can undergo cationic polymerization. For example, common monomers include isobutylene, isoprene, 1,3-pentane Alkene, cyclopentadiene, styrene, methyl styrene, tert-butyl styrene, vinyl methyl ether, vinyl isobutyl ether, etc. Isobutylene homopolymer (polyisobutylene) and its random copolymers (such as: butyl rubber) with other monomers (such as: isoprene) can only be synthesized by cationic polymerization, which is the largest output in the field of cationic polymerization Industrialized products. Isobutylene-based polymers generally have the characteristics of excellent air tightness, aging resistance...

Examples

Embodiment 1

[0061] At -90°C under nitrogen protection, add 10 mL of brominated isobutylene and p-methylstyrene random copolymer (BIMS) / hexane solution (concentration: 0.1 g / mL, bromine content is 0.9 wt%) to the polymerization reactor ) and 10 mL of isoprene (IP), mix well. Under stirring, add anisole and ethyl aluminum dichloride solution to initiate IP polymerization. Among them, the molar ratio of BIMS to IP is 1.2×10 -4 , the molar ratio of anisole to IP is 3×10 -4 , the molar ratio of dichloroethylaluminum to IP is 3×10 -3 . After 30 minutes of polymerization reaction, 2 mL of NaOH / ethanol solution with a mass fraction of 2% NaOH was added to terminate the reaction; after termination, the reaction system was washed with lye and water in sequence, and repeated three times. After purification, the polymer was obtained and dried in vacuum at 40°C. Obtain PIB-g-PIP graft copolymer 0.5g, its absolute weight-average molecular weight is 1920kg / mol, molecular weight distribution index (M...

Embodiment 2

[0063] The experimental method and reaction conditions are the same as in Implementation 1, except that the amount of ethylaluminum dichloride is reduced so that the molar ratio of it to IP is 2×10 -3 . Obtain PIB-g-PIP graft copolymer 0.45g, its absolute weight-average molecular weight is 1991kg / mol, M w / M n is 2.5, and the PIP mass content is 15%; the absolute weight-average molecular weight of the main chain isobutylene-based polymer segment is 1470kg / mol; the M of the branched polyisoprene segment n It is 89kg / mol, the 1,4-structure content accounts for 93%, and there is no cyclic structure.

Embodiment 3

[0065] Under the protection of nitrogen at 0°C, add 1 mL of brominated isobutylene and p-methylstyrene random copolymer (BIMS) / hexane solution (concentration: 0.1 g / mL, bromine content: 1.6 wt%) to the polymerization reactor ), 3,5-di-tert-butyl-4-hydroxybenzoic acid n-hexadecyl and ethylaluminum dichloride solution, mixed for 1 min. Under stirring, 19 mL of isoprene (IP) / hexane solution was added to start the polymerization. Among them, the molar ratio of BIMS to IP is 2.0×10 -4 , the molar ratio of 3,5-di-tert-butyl-4-hydroxybenzoic acid n-hexadecyl to IP is 1.6×10 -3 , the molar ratio of dichloroethylaluminum to IP is 8.0×10 -3 . Polymerization was terminated after 120min, and the aftertreatment process was the same as in Example 1. Obtain PIB-g-PIP graft copolymer 0.8g, its absolute weight-average molecular weight is 1340kg / mol, M w / M n is 1.6, and the PIP mass content is 13%; the absolute weight-average molecular weight of the main chain isobutylene-based polymer s...

technical field

[0001] The invention relates to the field of graft copolymers, in particular to a graft copolymer of polyisobutylene and polyisoprene and a preparation method thereof. Background technique

[0002] Cationic polymerization or cationic polymerization is one of the important components of polymer synthesis chemistry. There are also various types of monomers that can undergo cationic polymerization. For example, common monomers include isobutylene, isoprene, 1,3-pentane Alkene, cyclopentadiene, styrene, methyl styrene, tert-butyl styrene, vinyl methyl ether, vinyl isobutyl ether, etc. Isobutylene homopolymer (polyisobutylene) and its random copolymers (such as: butyl rubber) with other monomers (such as: isoprene) can only be synthesized by cationic polymerization, which is the largest output in the field of cationic polymerization Industrialized products. Isobutylene-based polymers generally have the characteristics of excellent air tightness, aging resistance...

Examples

Embodiment 1

[0061] At -90°C under nitrogen protection, add 10 mL of brominated isobutylene and p-methylstyrene random copolymer (BIMS) / hexane solution (concentration: 0.1 g / mL, bromine content is 0.9 wt%) to the polymerization reactor ) and 10 mL of isoprene (IP), mix well. Under stirring, add anisole and ethyl aluminum dichloride solution to initiate IP polymerization. Among them, the molar ratio of BIMS to IP is 1.2×10 -4 , the molar ratio of anisole to IP is 3×10 -4 , the molar ratio of dichloroethylaluminum to IP is 3×10 -3 . After 30 minutes of polymerization reaction, 2 mL of NaOH / ethanol solution with a mass fraction of 2% NaOH was added to terminate the reaction; after termination, the reaction system was washed with lye and water in sequence, and repeated three times. After purification, the polymer was obtained and dried in vacuum at 40°C. Obtain PIB-g-PIP graft copolymer 0.5g, its absolute weight-average molecular weight is 1920kg / mol, molecular weight distribution index (M...

Embodiment 2

[0063] The experimental method and reaction conditions are the same as in Implementation 1, except that the amount of ethylaluminum dichloride is reduced so that the molar ratio of it to IP is 2×10 -3 . Obtain PIB-g-PIP graft copolymer 0.45g, its absolute weight-average molecular weight is 1991kg / mol, M w / M n is 2.5, and the PIP mass content is 15%; the absolute weight-average molecular weight of the main chain isobutylene-based polymer segment is 1470kg / mol; the M of the branched polyisoprene segment n It is 89kg / mol, the 1,4-structure content accounts for 93%, and there is no cyclic structure.

Embodiment 3

[0065] Under the protection of nitrogen at 0°C, add 1 mL of brominated isobutylene and p-methylstyrene random copolymer (BIMS) / hexane solution (concentration: 0.1 g / mL, bromine content: 1.6 wt%) to the polymerization reactor ), 3,5-di-tert-butyl-4-hydroxybenzoic acid n-hexadecyl and ethylaluminum dichloride solution, mixed for 1 min. Under stirring, 19 mL of isoprene (IP) / hexane solution was added to start the polymerization. Among them, the molar ratio of BIMS to IP is 2.0×10 -4 , the molar ratio of 3,5-di-tert-butyl-4-hydroxybenzoic acid n-hexadecyl to IP is 1.6×10 -3 , the molar ratio of dichloroethylaluminum to IP is 8.0×10 -3 . Polymerization was terminated after 120min, and the aftertreatment process was the same as in Example 1. Obtain PIB-g-PIP graft copolymer 0.8g, its absolute weight-average molecular weight is 1340kg / mol, M w / M n is 1.6, and the PIP mass content is 13%; the absolute weight-average molecular weight of the main chain isobutylene-based polymer s...

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