文献类型：期刊文献

中文题名：苯乙烯阴离子本体聚合引发剂缔合及其机理的研究

英文题名：Aggregation of initiators and mechanism of styrene anionic bulk polymerization

作者：管涌[1];王宁[1];胡迪航[1];张晋玉[1];曹华威[1];郑安呐[1]

机构：[1]上海市先进聚合物材料重点实验室,超细材料制备与应用教育部重点实验室,华东理工大学材料科学与工程学院,上海200237

年份：2012

卷号：42

期号：5

起止页码：732

中文期刊名：中国科学：化学

外文期刊名：SCIENTIA SINICA Chimica

收录：CSTPCD;;北大核心:【北大核心2011】；CSCD:【CSCD2011_2012】；

基金：国家自然科学基金(5093302);上海市重点学科建设项目(B502);超细材料制备与应用教育部重点实验室项目(08DZ2230500)资助

语种：中文

中文关键词：阴离子聚合;本体聚合;机理;引发剂缔合;超分子结构

外文关键词：anionic polymerization, bulk polymerization, mechanism, aggregation of initiators, supramolecular structure

摘要：分别以正丁基锂和叔丁基锂为引发剂,采用自制管式流动反应装置,对较高温度下苯乙烯阴离子本体聚合动力学进行了研究.证实了正丁基锂主要以六元缔合结构形式引发聚合,并导致超分子团聚体的形成,从而使进一步的聚合因单体扩散受阻而受到限制,并伴随聚合转化率停滞平台(SCP)的产生.随后由于前期聚合累积的能量,使超分子结构完全解离.聚合温度越高,SCP持续时间越短.结果还表明,在正丁基锂引发剂中,存在一个以六元缔合结构为基础形成的更大的缔合体结构.原子力显微镜照片显示,超分子结构的直径分别为20～30nm和50～60nm.此外,在阴离子聚合过程中活性种的缔合结构只决定于初始引发剂的分子结构,而不同活性种缔合结构对阴离子聚合的链增长存在很大影响,从而解释了采用不同结构的锂系引发剂引发苯乙烯单体聚合时聚合速率存在巨大差异的原因.
With the help of a self-invented microflow reactor containing a spiral tubular, the kinetics of the anionic bulk polymerization of styrene initiated by n-butyllithium and t-butyllithium at the different temperatures were investigated. The results confirmed that hexameric-aggregated n-butyllithium could initiate the polymerization of St and form the supramolecular structure of polystyryllithium at first. Then, the polymer coils could block the diffusion of the monomers into the ion-pairs and result in a stationary-conversion platform （SCP）. The supramolecular would be disaggregated due to the energy accumulation. The higher the polymerization temperature is, the shorter SCP will be. The results also indicated a larger aggregation based on hexameric-aggregated n-butyllithiums existed. The results of AFM revealed that the diameter of such supramolecular aggregations ranged from 20-30 nm and 50-60 nm. Moreover, the structure of initiator aggregations, which had great effect on the initiating rate, was determined by the molecular structure of the initiator. Therefore, the findings could explain the wide difference in anionic polymerization rate using difference lithium initiators.