NEW STRATEGIES FOR SYNTHESIS OF PARTIALLY FLUORINATED HETEROCYCLES AS PRECURSORS FOR TRIFLUOROMETHYL-SUBSTITUTED POLYMERS

The building-block strategy is applied to the synthesis of new compounds with two five-membered heteroaromatic units. The heteroaromatic rings contain a fluorine atom which is activated towards nucleophilic displacement reactions by an adjacent trifluoromethyl group. The difunctional compounds can be converted into poly(arylene ether)s by base-catalyzed polycondensation with bisphenols or bisthiophenols. Trifluoromethylated poly(arylether oxazole)s and poly(arylthioether oxazole) s are obtained by this route. All representatives of these two new classes of polymers are soluble in common organic solvents. Reaction conditions for the polycondensation as well as thermal stability, glass transition temperatures, and molar masses of the polymers are described.