Preparing process for vinyl aromatic monomer - conjugated diene star type block copolymer

Abstract

The invention provides a method for preparing star type segmented copolymer of vinyl aromatic monomers - conjugated diolefin, characterized in that R1C-R2-COOR3 category compounds are used as the coupling agent, group R 2 is alkyl or phenyl group having 1-8 carbon atoms, R1 and R3 are alkyl or phenyl group having 1-6 carbon atoms, because polyfunctional group coupling agent containing no halogen element is used, no color change will occur to the copolymer during the coagulation process.

Description

technical field [0001] The invention relates to a preparation method of a vinyl aromatic monomer-conjugated diene star block copolymer. Background technique [0002] In the anionic polymerization technology for the preparation of vinyl aromatic monomer-conjugated diene star block copolymers, the coupling method is usually used. The usual coupling method is the reaction of a linear active polymer with a carbanion terminal with a multifunctional electrophilic compound (such as a halogen-containing multifunctional terminator-SiCl4, SnCl4), and the electrophilic atom (such as a halogen) is the active replaced by polymer chains. Since alkyllithium and negatively charged silane substitutes can rapidly produce metathesis reaction, a star-shaped block copolymer can be generated. When using an electrophilic halogen-containing multifunctional coupling agent, the amount of the coupling agent should theoretically be equivalent to the active polymer chain, but in order to overcome the ...

AI Technical Summary

Problems solved by technology

[0003] 1. Make the polymerization kettle polluted

[0004] 2. It is required that the polymerization and post-treatment system must be resistant to acid corrosion, and the equipment cost is relatively high

[0005] 3. A large amount of acid-containing sewage is produced in the post-treatment of the glue solution, which pollutes the environment and increases the cost of sewage treatment

[0006] 4. After the acid glue is stored for a long time, the color turns yellow and the glue deteriorates obviously

[0007] 5. Due to the halogen-containing coupling agent, after coupling, the generated lithium halide cannot be activated again, so it is necessary to add alkyllithium as a reducing agent during the hydrogenation reaction of the polymer