PHOTOREACTIVE DIIMIDE MODELS OF BENZHYDROLTETRACARBOXYLIC DIANHYDRIDE- SYNTHESIS, CHARACTERIZATION AND PHOTOPOLYMERIZATION

The synthesis, characterization and photopolymerization of bisimide co mpounds carrying a photoreactive methacryloyl group were investigated. Those photoreactive diimide models, derived from benzhydroltetracarbo xylic dianhydride (1), were prepared in N-methyl-2-pyrrolinone (NMP), either by a thermal or by a chemical imidization. In the thermal metho d, the bisimide carrying benzhydrol group was first synthesized by con densation of 1 with 4-tert-butylaniline at 180 degrees C. The hydroxyl group was then chemically modified by an excess of methacryloyl isocy anate (6) in NMP. In the chemical method, a photosensitive dianhydride , derived from the reaction between 1 and 6, was prepared and then con densed with aniline at 25 degrees C by means of propionic anhydride wi th triethylamine, which leads to the formation of the corresponding im ide. By means of IR, the photopolymerization of the methacrylic double bond that takes place in the presence of a photoinitiator under irrad iation at 365 nm was then investigated. It was found that the most eff ective photoinitiator for these photoreactive model compounds is the M ichler's ketone/triethanolamine system. The further aim of the present investigation is to prepare novel negative-type photosensitive polyim ides.