FACILE SYNTHESIS OF POLYESTERS CONTAINING NORBORNADIENE RESIDUES IN THE MAIN-CHAIN BY THE POLYADDITION OF 2,5-NORBORNADIENE-2,3-DICARBOXYLIC ACID WITH BIS(EPOXIDE)S

Polyesters containing norbornadiene (NBD) residues in the main chain w ere prepared by the polyaddition of 2,5-NBD-2,3-dicarboxylic acid (NDC ) with various bisepoxy compounds. The reaction of NDC with bisphenol A diglycidyl ether proceeded very smoothly using tetraphenylphosphoniu m iodide as a catalyst in N-methylpyrrolidone at 80 degrees C, and the polymer containing NBD residues in the main chain with a number avera ge molecular weight of 35000 was obtained in high yield. Various NBD p olyesters were also prepared by the reaction of NDC with certain bisep oxy compounds. The photochemical properties of the polyesters were eva luated in the him state. The structure and the glass transition temper ature of the resulting polyesters affected hardly the rate of isomeriz ation of the NBD residues in the polymers. The rate of isomerization o f the polymer film increased greatly by the addition of 4,4'-bis(dieth ylamino)benzophenone as a photosensitizer. The photo-irradiated polyme rs containing quadricyclane moieties released about 90 kJ/mol of therm al energy.