以己二酸二乙酯为偶联剂的正丁基锂/四氢糠醇乙醚体系合成苯乙烯-丁二烯共聚物

Preparation of styrene-butadiene copolymer with n-butyl lithium/ethyl tetrahydrofufuryl ether catalyst system using diethyladipate as coupling agent

以正丁基锂(n-BuLi)为引发剂,环己烷与己烷混合作为溶剂,四氢糠醇乙醚(ETE)为极性调节剂,己二酸二乙酯(DEAP)为偶联剂,采用负离子聚合法合成了苯乙烯-丁二烯共聚物,考察了ETE用量及反应温度对聚合反应速率、共聚物组成以及共聚物微观结构的影响,也考察了DEAP用量对偶联效率的影响。结果表明,随着ETE用量的增加或聚合温度的升高,聚合反应速率逐渐增大。当反应温度为35~50℃、ETE用量为200~300μg/g时,共聚物中乙烯基结构含量随ETE用量的增加和聚合温度的降低而增大,乙烯基的质量分数最多可达67.2%,苯乙烯单元在共聚物中趋于无规分布。当DEAP与n-BuLi的摩尔比为0.25时,偶联效率最高可达60.90%。

Styrene-butadiene copolymer was synthesized by anionic polymerization method, using n-BuLi as initiator, cyclohexane and hexane were mixed as solvent, ethyl tetrahydro- furfuryl ether （ ETE ） as polar modifier, and diehtyl adipate （DEAP） as coupling agent. The effects of amount of ETE and polymerization temperature on rate of polymerization, composition and microstructure of the copolymer, and the effect of amount of DEAP on coupling efficiency were investigated. The results showed that the rate of polymerization increased gradually with increasing amount of ETE and increase of polymerization temperature. When the polymerization temperature was 35 - 50 ℃, the amount of ETE were 200 - 300 μg/g, the content of vinyl structure in styrene-butadiene copolymer increased with the increase amount of ETE and the decrease of polymerization temperature, the mass fraction of vinyl was up to 67.2% and monomer styrene was random distributed in the copolymer. When the mole ratio of DEAP to n-BuLi was 0. 25, coupling efficiency could be tip to 60. 9%.