Abstract

A comparative study of the thermal behavior of acrylonitrile-acrylic acid copolymers synthesized by conventional radical polymerization and reversible addition-fragmentation chain transfer polymerization to deep conversions with different modes of introducing acrylic acid into the reaction is carried out. It is shown that, at similar average compositions of conventional copolymers, the difference in their compositional heterogeneity leads to an unpredictable change in the activation energy of cyclization, the degree of stabilization, and the thermal stability of the copolymers. In contrast, for copolymers of the same average composition obtained under reversible chain transfer conditions, a change in the chain microstructure, that is, the distribution of acrylic acid units along the chain, makes it possible to control the rate of cyclization while maintaining a high thermal stability of the copolymers.

中文翻译：

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合成方法对丙烯腈-丙烯酸共聚物碳纤维前驱体性能的影响

摘要

对通过常规自由基聚合和可逆加成-断裂链转移聚合合成的丙烯腈-丙烯酸共聚物的热行为进行了比较研究，该反应具有将丙烯酸引入反应的不同方式的深度转化。结果表明，在常规共聚物的平均组成相似的情况下，其组成异质性的差异导致共聚物的环化活化能，稳定度和热稳定性发生不可预测的变化。相反，对于在可逆链转移条件下获得的具有相同平均组成的共聚物，链的微观结构发生变化，即丙烯酸单元沿链的分布，