Tin‐coupled star‐shaped block copolymer of styrene and butadiene (II) properties and application

A novel tin‐coupled star‐shaped block copolymer (SB‐B)₄Sn was synthesized by anionic polymeric techniques. This new copolymer exhibited two different types: One was star‐shaped polybutadiene‐b‐poly(butadiene‐ran‐styrene) (S‐PB‐PSB), and the other was star‐shaped polybutadiene‐b‐poly(butadiene‐ran‐styrene)‐b‐polystyrene (S‐PB‐PSB‐PS). In this article, properties of (SB‐B)₄Sn were contrasted with that of tin‐coupled star‐shaped random styrene‐butadiene rubber (S‐SBR) and S‐SBR/cis‐BR blend rubbers. Physical property testing results showed that (SB‐B)₄Sn possessed good mechanical properties like S‐SBR. Rheological study indicated that these star‐shaped block copolymers had good processing properties. Rubber processing analyzer (RPA) spectra showed that the dispersion of additives in (SB‐B)₄Sn and S‐SBR/cis‐BR blend rubber was much better than that in S‐SBR. Dynamic mechanical thermal analyzer (DMTA) spectra showed that (SB‐B)₄Sn had a good combination of low rolling resistance and high wet skid resistance, which made it satisfactory materials to produce high performance tire tread. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009