SYNTHESIS AND PROPERTIES OF NOVEL PHOTOSENSITIVE POLYIMIDES CONTAINING CHALCONE MOIETY IN THE MAIN-CHAIN

Two chalcone-derivative isomers, 4,4'-diaminochalcone (4DAC) and 3,3'- diaminochalcone (3DAC), were synthesized and used as monomers together with tetracarboxylic dianhydrides to prepare novel photosensitive pol yimides that contain a chalcone moiety in the main chain. The polyimid es were characterized and their photochemical behavior was investigate d as thin films and in solutions with the aid of ultraviolet and infra red spectroscopy. Compared with 4DAC-based polyimides, the 3DAC-based polyimides exhibited lower glass transition temperatures and higher ph otocrosslinking rates of the carbon-carbon double bond as well as high er photosensitivities obtained from the exposure characteristic curves , suggesting that an increase in the photoreactivity of the 3DAC-based polyimides might arise from the improved flexibility of their backbon es. The polyimide from 3DAC and 6FDA (2,2-bis[3,4-dicarboxypheny]hexaf luoropropane dianhydride) showed a photosensitivity of 33 mJ/cm(2) wit h a contrast of 1.5 upon light irradiation using a Xenon lamp. (C) 199 8 John Wiley & Sons, Inc.