乙烯基单体的结构与聚合类型之间的关系

Relationship between Structure of Vinyl Monomers and Types of Polymerization

连锁(链式)聚合反应是制备高分子化合物的一类重要反应.也是《高分子化学》课程学习的一项重要知识内容。在讲授连锁聚合反应中,乙烯基单体对聚合类型的选择性一直是高分子化学教学过程中的一个重点及难点问题。本文从取代基的诱导效应、共辄效应及取代基常数三个方面定性、定量地讨论了取代基电子效应的方向和强度.并以偏二氯乙烯与偏二氟乙烯、丙烯酸甲酯与醋酸乙烯酯为例分析了两组单体对聚合类型存在差异性的原因,以期帮助学生理解乙烯基单体对聚合类型的选择性。

Chain polymerization is an important reaction to prepare polymer compounds, and is also an important knowledge in the course of polymer chemistry. In the course of teaching chain polymerization, the selectivity of vinyl monomers on polymerisation types has always been a key and difficult problem in process of polymer chemistry teaching. In this paper, the direction and intensity of the substituent electron effect are discussed qualitatively and quantitatively from three aspects: the induction effect, the conjugation effect and the substituent radical constant, then the reasons for the difference in polymerization types between the two groups of monomers were analyzed by using vinylidene chloride and vinylidene fluoride, methyl acrylate and vinyl acetate as examples, in order to help students understand the selectivity of the vinyl monomers on the type of polymerization.