Synthesis of Acetal-contaming Main Chain Degradable Type Photosensitive Polyimides

A series of main chain degradable polyimides 6 were prepared by the polyaddition of acetalcontaining diamine monomer 4 with various aromatic tetracarboxylic anhydrides 5, followed by chemical imidization without isolating. The structures of polyimides obtained were confirmed by infrared, 1 H nuclear magnetic resonance (NMR) and 13 C NMR spectroscopy. Their thermal stability, solubility and transparency have also been investigated. Furthermore, the acid-catalyzed degradation reactions of model compound 7 and polyimide 6d have been studied. These results suggest that polyimides 6 can be recognized as photosensitive polyimides.