Photosensitive copolyamides containing phenylenediacryloyl units in the main chain

A series of photosensitive copolyamides with photocrosslinkable double bond s in the main chain were synthesized by a direct polycondensation reaction of various dicarboxylic acids and 1,4-phenylenediacrylic acid (p-PDA) with 4,4'-diphenylmethanediisocyanate (MDI) in the presence of tripropylamine as catalyst. These polymers are soluble in polar aprotic solvents and give cl ear flexible films when cast upon a glass plate. The polymeric films are cr osslinked and insolubilized in solvents on irradiation of the light due to photodimerization reaction of ethylenic unsaturated double bond of p-phenyl enediacryloyl unit in the polymer. The polymers were characterized by visco metric measurements, softening points and thermogravimetric data. Their str uctures were confirmed by IR, H-1-NMR spectra and elemental analysis.