Synthesis of 1,2,4-Triazole Poly(aryl ethers) via Heterocyclic-Activated Displacement Polymerization

Abstract

The synthesis and characterization of new monomers and polymers containing the 1,2,4-triazole unit are discussed. The monomers were synthesized via a route that allowed the preparation of a variety of 3,5-bis(4′-fluorophenyl)-4-aryl-l,2,4-triazoles. lH, 13C, and 19F NMR have proved to be valuable in the evaluation of the degree of activation in these weakly activated fluoro monomers. Model reactions with m-cresol were performed on these new monomers to ascertain that they were indeed good candidates in a poly(aryl ether) synthesis. Reaction times, temperatures, and solvent systems had to be adjusted to optimize conditions for these weakly activated systems. The monomers were polymerized with various bisphenols in high-boiling polar aprotic solvents in the presence of potassium carbonate to yield high molecular weight, amorphous polymers which were thermally stable and amenable to common processing conditions. The polymers had Tg's ranging from 185 to 230 °C, had intrinsic viscosities between 0.40 and 1.45 dL/g, and showed dynamic mechanical behavior consistent with other high-temperature thermoplastics. © 1993, American Chemical Society. All rights reserved.