偶联法高苯乙烯橡胶的合成

Synthesis of high styrene rubber by coupling reaction

以环己烷为溶剂、苯乙烯和丁二烯为单体、正丁基锂（n-BuLi）为引发剂、四氢呋喃（THF）为结构调节剂,通过活性负离子溶液聚合及偶联合成了高苯乙烯橡胶。研究了聚合温度、苯乙烯/丁二烯（质量比）、相对分子质量、n（THF）/n（n-BuLi）、丁二烯封端对高苯乙烯橡胶力学性能的影响及n（THF）/n（n-BuLi）对偶合效率的影响。结果表明,当苯乙烯/丁二烯质量比为60/40、THF/n-BuLi物质的量比相对为1.0~1.5时,在（63±3）℃下聚合,（75±5）℃下偶合可得到力学性能较好的高苯乙烯橡胶,其数均相对分子质量为（15~20）×104,相对分子质量分布为2.0~2.3。

High styrene rubber was synthesized by living anionic solution polymerization and coupling reaction with cyclohexane as solvent,styrene（St） and butadiene（Bd） as monomers,n-BuLi as initiator,tetrahydrofuran as structure regulator,tin tetrachloride as coupling agent.The effects of polymerization temperature,St/Bd（mass ratio）,relative molecular mass,THF/n-BuLi,terminated by butadiene on mechanical properties of high styrene rubber were studied.Effect of THF/n-BuLi on coupling efficiency was studied.The results showed that the high styrene rubber with number-average molecular mass of 15×104~20×104,and its distribution of 2.0~2.3 could be obtained at polymerization temperature（63±3） ℃,St/Bd（mass ratio） was 60/40,THF/n-BuLi（mole ratio）1.0~1.5,coupling reaction temperature（75±5） ℃,and under this conditions the high styrene rubber had better mechanical properties.