Preparation method of hydrogenated styrene-butadiene-styrene block copolymer

Abstract

The invention relates to the field of high polymer synthesis and in particular discloses a preparation method of a hydrogenated styrene-butadiene-styrene (SBS) block copolymer. The preparation methodof the hydrogenated styrene-butadiene-styrene block copolymer is characterized by comprising the following steps: under the protection of inert gas, taking organic lithium as a catalyst; putting styrene into a cyclohexane solvent and carrying out first-section polymerization reaction; meanwhile, adding a composite-structure regulator; then adding butadiene and carrying out second-section polymerization reaction; after polymerization is finished, adding the styrene and carrying out third-section polymerization reaction to obtain a basic adhesive SBS for hydrogenation; carrying out hydrogenationreaction on the basic adhesive for the hydrogenation by adopting a homogeneous-phase rhodium series catalyst to obtain a product. The preparation method provided by the invention has the advantages of reasonable technology design, less dosage of a hydrogenation catalyst, high catalyst activity and selectivity, moderate reaction conditions and high product purity and yield, and is suitable for being widely popularized and applied.

Description

(1) Technical field [0001] The invention relates to the field of polymer synthesis, in particular to a method for preparing a hydrogenated styrene-butadiene-styrene block copolymer. (2) Background technology [0002] Styrene-butadiene-styrene block copolymer (SBS) is a basic material, which is widely used in the four major fields of rubber products, plastic modifiers, adhesives and asphalt modifiers. Bond, weather resistance and thermal stability are insufficient, limiting its application. Hydrogenated styrene-butadiene-styrene block copolymer (SEBS) is to hydrogenate the soft segment in SBS - polybutadiene to form polyethylene-poly-1-butene block, which is a kind of use A wide range of new block copolymers is an effective way to make up for the shortcomings of SBS such as insufficient weather resistance and thermal stability. Compared with SBS, SEBS has a series of excellent properties, such as thermal oxygen resistance, ozone resistance, UV resistance, creep resistance, ...

AI Technical Summary

Problems solved by technology

① Heterogeneous catalysts are supported by group VIII metals on diatomite. Heterogeneous catalysts have low activity and harsh conditions. They need to be carried out under high temperature and high pressure, which will lead to polymer decomposition and gelation of the reaction system, resulting in high energy consumption. At the same time, the reaction system viscosity and polymer steric hindrance also adversely affect the catalyst activity, thereby increasing the amount of catalyst used, and the catalyst's selectivity for hydrogenation of conjugated diene units also needs to be improved.

Hydrogenation of SBS to prepare SEBS block copolymers, seeking a catalytic system with high activity, high degree of hydrogenation, and good selectivity, has both important theoretical significance and realistic industrial application background. At present, more researches are Ruthenium complex catalytic system, but the research on rhodium complex catalytic system for SBS hydrogenation has not been reported