Polymer Synthesis via a Diels–Alder Reaction between Bis(Isobenzofuran)s and Bis(Phenylacetylene)s Containing Preformed Phthalimide Rings

Abstract

Polymers have been prepared by the Diels–Alder reaction between novel bis(isobenzofuran)s and bis(phenylacetylene)s containing preformed phthalimide rings. The initial polymer undergoes a thermal rearrangement without volatile evolution that effectively prevents a retro Diels–Alder reaction from occurring. The polymers were soluble in common organic solvents such as chloroform, N-methyl-2-pyrrolidinone, N, N-dimethylacetamide and chlorinated aromatic solvents. The polymers exhibited glass transitions ranging from 251 to 359 °C and a 10%weightloss ranging from 451 to 486 °C in air and 482 to520 °C in helium as determined by thermogravimetric analysis. Thissynthetic approach offers advantages over other Diels–Alder polymerizations since no volatile by-products are generated and a thermal rearrangement eliminates a retro Diels–Alder reaction.