丁二烯/苯乙烯阴离子连续溶液共聚合研究

在2L的搅拌釜式反应器中，对以正丁基锂（n-BuLi)、THF和环己烷分别为引发剂、调节剂和溶剂的丁二烯／苯乙烯阴离子连续溶液共聚合进行了实验研究。用气相色谱、凝胶渗透色谱和核磁共振仪分别实测了单体转化率、共聚物的分子量分布和共聚物的微观结构。考察了平均停留时间和THF／Li^ 比值对丁苯连续共聚合的转化率、分子量及分子量分布和共聚物微观结构的影响。研究结果表明，在THF存在下，由n-BuLi引发的丁苯阴离子连续溶液共聚合可获得微观结构较合适的丁苯无规共聚物；平均停留时间对转化率有明显影响，而对共聚物的微观结构的影响较小；THF／Li^ 比值对聚合速率及共聚物中的结合苯乙烯含量有明显影响，对共聚物的微观结构如1，2－结构 1，4－结构及顺反结构也有一定程度的影响，THF／Li^ 比值对共聚物的平均分子量有显著的影响，因而共聚物的分子量分布无明显影响。研究表明合适的THF／Li^ 比值为70。

Studies on Anionic Continuous Solution Copolymerization of Butadiene/Styrene with n-BuLi Initiator

The anionic solution copolymerization of butadiene/styrene with n-butyllithium(n-BuLi) initiator, tetrahydrofuran(THF) modifier, and cyclohexane solvent, was studied. The study was carried out experimentally in an agitated tank reactor of 2 liters employing continuous operation mode. The reaction conversion rate of monomers, molecular weight and distribution of the copolymer, and micro-structure of the copolymer were analyzed by gas chromatograph, gel permeation chromatograph, and nuclear magnetic resonance, respectively. The effects of the mean residence time and the THF/Li+ ratio on the reaction conversion rate, molecular weight and molecular weight distribution, and the micro-structure of copolymer were investigated. The results showed that a randomized copolymer of butadiene/styrene with proper micro-structure can be obtained by anionic continuous solution copolymerization of butadiene/styrene with n-butyllithium(n-BuLi) initiator, tetrahydrofuran(THF) modifier, and cyclohexane solvent. The mean residence time has remarkable effect on the reaction conversion rate, and has effect to a certain extent on the micro-structure of copolymer. The effect of the THF/Li+ ratio on the copolymerization rate of butadiene and styrene are notable. The reasonable THF/Li+ ratio was found to be 70. The effect of the THF/Li+ ratio on the combined styrene is significant. The effect of the THF/Li+ ratio has effect to a certain extent on 1,2- structure, 1,4- structure , and cis/trans-structure of the copolymer. The results also showed that the effect of the THF/Li+ on the average molecular weight of copolymer is considerable, and that the effect of THF/Li+ ratio on the molecular weight distribution is not significant.