环戊二烯阳离子聚合的研究——聚合反应条件对产物分子量的影响

CATIONIC POLYMERIZATION OF 1,3-CYCLOPENTADIENE INITIATED BY TiCl_4 ——Effect of reaction conditions on polymer's molecular weight

随着石油化工和煤化工的迅速发展 ,环戊二烯的产量大幅度增加 ,其聚合物已用于聚丙烯等通用塑料的改性 ,赋予其热封性、气体阻隔性。本实验以TiCl4 为引发剂 ,研究不同浓度、温度、溶剂中引发环戊二烯的阳离子聚合。结果表明 ,溶剂对产物的分子量和分子量分布的影响最为显著 ,这与离子对的状态有密切的关系 ;并且用甲苯作溶剂时 。

With the development of oil and coal industries, a great amount of 1,3 cyclopentadiene is produced. The poly (1,3 cyclopentadiene) has been used as reinforcing agent, heat sealing promoter for polypropylene and to reduce permeability of films to both oxygen and aroma. In this paper, cationic polymerizations of 1,3 cyclopentadiene initiated by TiCl 4 were studied by changing the reaction conditions, such as catalyst content, monomer content, solvent, reaction time and polymerization temperature. The results showed that the effect of solvents on the molecular weight of polymer was significant which was responsible for the situation of ion pairs. High polymer was obtained using 1,2 dichoroethane whereas low polymer formed in cyclohexane. 1HNMR evidences showed that toluene was involved in the chain transfer process and result p tolyl groups were found in the polymer.