高性能聚邻苯二甲腈树脂的固化新方法研究

Phthalonitrile resins (CN resins) have been recognized as a type of high performance resins. Their thermal properties are comparable to those of well-known polyimides. Unfortunately,the radical reaction of CN resins did not occur until high cure temperatures of 350-400 oC were used. The cure reaction of CN resins can be initiated at lower temperatures around 250 oC, by addition of curing agents such as aromatic amine or phenol, where the nucleophilic addition-type cure reaction may be responsible for the lower cure temperature. However, cure reactions were still sluggish and post-cure under high temperatures approaching 400 oC for an extended period of time (around 8h)are still required for conventional CN resins, for which the application ranges were limited. In this project, unsaturated group with relatively faster radical reaction rate such as phenylethynyl, was introduced into CN resins. The aim was to explore new approach of promoting cure reaction of CN resins by virtue of copolymerization between CN and unsaturated groups.

聚邻苯二甲腈树脂（CN树脂）具有优异的耐高温性能，且与众所周知的聚酰亚胺相当。但是，CN树脂热自由基固化需要在350-400 oC的高温区才能发生，且固化速度极慢。尽管加入固化剂（一般为芳胺或酚类）后（固化机理主要以亲核加成历程为主），CN树脂的固化可以在250 oC前后启动，但固化速率仍然缓慢，后固化仍需在接近400 oC长时间（一般为8h）热处理才能完成。这大大阻碍了CN树脂的应用。本项目通过在CN树脂体系中引入热自由基固化速度相对更快的不饱和结构（如苯乙炔），利用芳氰基和不饱和结构的共聚反应，寻求加速固化CN树脂的新方法。

聚邻苯二甲腈树脂（CN树脂）是一类重要的高性能聚合物材料。然而，缓慢的热聚合反应特征限制了其使用范围。本项目，拟通过构建不饱和树脂/CN树脂体系，研究基于自由基的协同固化体系。结果发现，脂环族结构能有效的加速CN树脂的固化，聚合机理与传统的固化剂不同，以异吲哚啉结构的生成为主，历程很可能是自由基机制。该结果，为CN树脂的设计和改性提供了新的思路和方法。