Aromatic dianhydrides being substituted in the positions ortho to the bridging moiety, said substituent groups including halogen, alkyl, hydroxy, nitro, cyano, ester, alkoxy, perfluoroalkyl, mercapto and thioester groups, said dianhydrides providing certain beneficial properties to polyimides prepared therefrom.
芳香族二酐在桥基的正交位置被取代,所述取代基团包括卤素、烷基、羟基、硝基、
氰基、酯基、烷氧基、
全氟烷基、巯基和
硫酯基团,所述二酐可为由此制备的聚
酰亚胺提供某些有益特性。