异构化PI单体的合成方法及其对PI t_g的影响分析

Synthesis of isomeric monomers and its influence on t_g of PI

综述了异构化聚酰亚胺(PI)领域中异构二酐和异构二胺单体的合成方法,其中,异构二酐的合成方法主要以空气氧化法、氧化偶联、Ullmann缩合、芳香族亲核取代法为主;异构二胺的合成方法比较成熟,首先采用硝化或亲核取代方法合成不同结构的二硝基化合物,然后将其还原为二胺。最后讨论了异构单体合成方法对PI玻璃化转变温度(t_g)的影响,由异构二酐单体所得异构化PI的t_g较高,而由异构二胺单体制备的异构化PI,通常是由对位二胺所得PI的t_g最高,间位的最低。

This paper reviews the synthesis of isomeric dianhydride and isomeric diamine monomers which are categorized as isomeric polyimide（PI）. The synthesis methods of isomeric dianhydride include air oxidation,oxidative coupling,Ullmann condensation and aromatic nucleophilic substitution. The proven synthetic route of isomeric diamine is through the reduction of dinitro compounds,which are prepared via nitration or nucleophilic substitution. The effects of these synthesis methods of isomeric monomers on glass transition temperature（tg）of PI are discussed. The tg of PI made from isomeric dianhydrides is high. The tg of PI from para diamine is highest and that from meta diamine is lowest among those of PI from isomeric diamine monomers.