SEBS (i.e., polystyrene-block-poly(ethylene-co-1-butene)-block-polystyrene), prepared by SBS (i.e., polystyrene-block-polybutadiene-block-polystyrene) hydrogenation, has a good-function thermoplastic elastomer (TPE). Process of hydrogenation is not an easy task. Thermal processing impracticability may be another huddle in market expansion. Thus, we disclosed another simple one pot synthesis route for triblock copolymer like SEBS, performing coordinative chain transfer polymerization (CCTP), to grow polyolefin chains from organozinc compounds bearing styrene moiety, using a special initiator anionic styrene polymerization, allowing polystyrene chain growth from Zinc-carbon sites as well as from styrene moieties. Although the huge scale for preparation of highly pure organozinc compounds bearing styrene moiety was very difficult, we overcame with developing the synthesis of (CH2=CHC6H4CH2CH2CH2)2Zn (4), as a stable crystalline solid. 4 worked very well as chain transfer agent, enabling production of SEHS- PS-block-poly(ethylene-co-1-hexene)-block-PS which exhibits similar stress-strain curve as the commercial-grade SEBS. The SEHS better dispersed with PP, being a nice toughening agent in PP-blending than the commercial-grade SEBS. Furthermore, the SEHS was less viscous, exhibiting better workability.
