Synthesis, characterization and thermal crosslinking behavior of new poly(aryl ether sulfone)s based on naphthalene isomers

Four new poly(aryl ether sulfone)s containing naphthalene rings were synthesized from 1,5- and 2,7-bis-(4-fluorosulfonyl)naphthalene isomers with different diphenols. These polymers exhibited high glass transition temperatures and good thermal stability. The glass transition temperatures ranged from 220 to 236 degrees C and the 5% weight-loss temperatures were above 423 degrees C. As the four polymers were treated at 300 degrees C, the glass transition temperatures of polymer series a obviously increased and the polymers became insoluble in common organic solvents including NMP, DMAc, and chloroform, etc., but the series b did not, which indicate that a thermal crosslinking reaction via free radicals happened leading to crosslinked polymers.