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一、前言从理论上说,环烯烃有可能通过双键开裂生成聚环烯或者通过开环而生成不饱和线型高聚物。但是,直到几年前为止,所有关于将环烯烃转化为高分子量均聚物的尝试都没有成功。为了找出失败的原因,有必要设想两种可能发生的反应情况。环烯烃与内部具有双键的非环烯烃是有联系的。如所周知:这一类烯烃(例如2-丁烯)一般是不大可能或者不可能聚合的。曾经用来说明这一现象的理由之一是:双键两边的碳原子因引入大体积取代基而出现了位阻作用。近几年来,我们已经有足够的理由可以
I. INTRODUCTION In theory, it is possible for cycloalkenes to cleave through double bonds to form polycycloolefins or to form unsaturated linear polymers through ring opening. However, until a few years ago, all attempts to convert cycloolefins to high molecular weight homopolymers failed. In order to find the cause of the failure, it is necessary to envisage two possible reactions. Cycloalkenes are linked to acyclic olefins having double bonds inside. It is well known that this class of olefins, such as 2-butene, is generally not likely or possible to polymerize. One of the reasons that have been used to illustrate this phenomenon is that the carbon atoms on both sides of the double bond exhibit steric hindrance due to the introduction of bulky substituents. In recent years, we already have enough reasons to do so