Influence of liquid polybutadiene on crosslinking network and mechanical properties of SSBR/BR

The treated distillate aromatic extract (TDAE) is widely used in tread compounds. However, polycyclic aromatic hydrocarbons (PAHs) contained in TDAE is serious harm to the environment and human. In this paper, liquid polybutadiene (LPB) of different brands was used to replace TDAE to plasticize solution polymerized styrene-butadiene rubber/cis-1,4-polybutadiene rubber (SSBR/BR). The effects of liquid polybutadiene instead of TDAE on crosslinking network and mechanical properties of matrix rubber were studied. LPB could participate in vulcanization reaction (different from TDAE). The results showed that LPB effectively reduced the critical strain amplitude of Payne effect (ameliorated filler dispersion) compared with TDAE plasticizing SSBR/BR. The degree of crosslinking decreased slightly, but there was no significant difference in rolling resistance and wet skid resistance at the same sulfur content. Changing the sulfur content, the wet skid resistance of tread and tensile strength of SSBR/BR vulcanizate plasticized by LPB were significantly improved, and the effect of LPB with high 1,2-vinyl content was better. In a word, LPB as a new environmental protection plasticizer can be used to effectively replace the TDAE plasticizing SSBR/BR.