A series of new photosensitive polyesters with pendant cinnamic ester groups were prepared from glycidyl cinnamate(GC) and phthalic anhydride(PAH), maleic anhydride(MAH) and succinic anhydride(SAH) by the ring opening alternating copolymerization.
Copolymerization of GC and each of PAH, and SAH were carried out in organic solvents such as cyclihexanone and hexamethyl phosphoramide, or in molten states, Copolymerization of GC and MAH in molten state was not succeeded because of the gelatien of the reactant. It was observed that the GC-PAH and GC-SAH polymerized in molten state have higher viscesity than those obtained in organic solvents.
The polyester from GC and MAH containing 5 wt% of 5-nitroacenaphtene as a sensitizer has the same relative sensitivity as KPR. The rate constant of photocrosslinking of polyesters was 3.47 10-3 mol%-1 sec-1.