Preparation of cis- and trans-Dicyclohexyl-3,3',4,4'-tetracarboxylic dianhydrides and Transparent Polyimides thereof

摘要

Aromatic polyimides (PIs) are well known as high-performance polymer materials and have been widely used in aerospace and microelectronics industries. The wholly aromatic polyimides are absolutely infusible and colored brown or slightly yellow. We have isolated the monomers, (1R, 1'S, 3R, 3'S, 4R, 4'S)-dicyclohexyl-3,3',4,4'-tetracarboxylic dianhydride (trans-DCDA, I) and (1R, 1'S, 3R, 3'S, 4'S, 4'R)-dicyclohexyl-3,3',4,4'-tetracarboxylic dianhydride (cis-DCDA, II) in a pure form. And we prepared novel transparent and soluble PIs derived from cis- and trans-dicyclohexyl-3,3',4,4'-tetracarboxylic dianhydrides and various aromatic diamines.