杂臂星型苯乙烯-丁二烯共聚物的结构与性能

采用自制的含碳锡键和聚二烯烃臂的多官能团大分子有机锂作为引发剂,四氢呋喃为结构调节剂,环己烷为溶剂,阴离子聚合法合成了杂臂星型苯乙烯-丁二烯共聚物;依据多官能团大分子引发剂中二烯烃的不同,所合成的共聚物分别为PI-Sn-(SBR)3和PB-Sn-(SBR)3。用GPC1、H-NMR和DSC分析了杂臂星型共聚物的结构,并研究了硫化胶的物理机械性能和动态力学性能。结果表明,杂臂星型共聚物中聚二烯烃臂中1,4结构质量分数约为90%;苯乙烯-丁二烯共聚臂中1,2-PB质量分数约为45%。DMTA测试表明杂臂星型共聚物在保持低滚动阻力的同时具有更好的抗湿滑性和低温性。两种共聚物都满足高性能轮胎胎面胶的要求。

Structure and properties of miktoarm star-shaped styrene-butadiene copolymers

Using a multifunctional macromolecule containing an Sn-C bond and a polydiene arm as an initiator and tetrahydrofuran as a regulator, styrene and butadiene were copolymerized via anionic polymerization, forming two kinds of novel miktoarm star-shaped copolymers, polyisoprene-Sn-(SBR)_3 and polybutadiene-Sn-(SBR)_3. The average molecular weight and polydispersity index, microstructure, unit composition, and glass transition tempera-tures (T_g) of the miktoarm star-shaped copolymers were investigated using GPC, ~1H-NMR, and DSC. The proper-ties of PD-Sn-(SBR)_3(PD=polydiene) were compared with those of two blend rubbers, star-shaped random sty-rene-butadiene (S-SBR)/natural rubber and S-SBR/cis-1,4-polybutadiene (cis-BR). Dynamic mechanical ther-mal analysis showed that the miktoarm star-shaped copolymers PD-Sn-(SBR)_3 possess a combination of low rolling resistance and high wet skid resistance and constitute an ideal candidate for the rubber in high performance tire tread.