苯乙烯阴离子高温本体聚合引发机理的新发现(一)

New Insight in Initiating Mechanism of Anionic Bulk-Polymerization of Styrene at High Temperature(1)

采用一种新的研究方法,进行了苯乙烯阴离子的高温本体聚合,突破了传统阴离子动力学研究中仅采用高真空、稀溶液、低转化率的局限。结果表明:当聚合转化率小于4%时,聚合反应机理完全符合经典阴离子活性聚合的理论;但继续聚合后将出现一个转化率停滞平台和聚合速率再次升高的现象,与传统理论不同。假设活性种引发聚合后形成的大分子链不再反向团聚,进行聚合动力学的理论推导。将实验结果与传统理论进行比较,提出了阴离子聚合过程中还存在一个团聚以及引发剂缔合结构向活性种离解过程的假设。

Aiming at solving the several queries in the classic theory of the anionic polymerization,with the help of a self-invented device containing a spiral tubular reactor,the kinetics of the anionic bulk polymerization of styrene was investigated.Results showed that the polymerizations followed the classic theory of the anionic polymerization before 4% of the conversion.After that,however,there would appear a stationary-conversion platform and then a significant increase in polymerization rate.In order to explain the experimental results,a kinetics equation of the anionic polymerization was derived based on a hypothesis,in which polymerized molecular chains initiated by the active species in the initiator would never aggregate again to maintain the balance between aggregated initiators and active species according to the classic theory.In the light of the kinetics equation,the simulation results based on the experiments implied that there might exist an aggregation process and then a dissociation of aggregated initiator during the anionic polymerization.