POLY(ARYL ETHER OXAZOLE)S WITH TRIFLUOROMETHYL GROUPS

Poly(aryl ether oxazole)s with trifluoromethyl groups bound to the oxa zole moieties have been synthesized from a bisoxazole monomer containi ng two activated fluorine atoms by nucleophilic displacement with bisp henols. The poly(aryl ether oxazole)s are completely amorphous with on e exception. Their glass transition temperatures are between 136 and 1 91-degrees-C, depending on the structure of the bisphenol monomer. Due to their amorphous nature they are soluble in a number of common orga nic solvents. They have been thoroughly characterized by IR and NMR sp ectroscopy, DSC, GPC, and thermogravimetry. The polymers exhibit an un expected instability at high temperatures. While other oxazole-contain ing polymers are stable in air up to more than 450-degrees-C, the new poly(aryl ether oxazole)s already start to lose weight at temperatures of about 310-degrees-C. This is attributed to their special oxazole s tructure, and a strategy is proposed and studied to overcome this low thermal stability.