Oxygen plasma resistant phenylphosphine oxide-containing poly(arylene ether)s

Abstract

Phenylphosphine oxide-containing poly(arylene ether)s were prepared by the aromatic nucleophilic displacement reaction of a new phenylphosphine oxide-containing bisphenol with activated aromatic difluorides in the presence of anhydrous potassium carbonate in N, N′-dimethylacetamide at 155°C or in sulfolane at 200°C. The phenylphosphine oxide-containing bisphenol was prepared in two steps from bis(4-fluorophenyl)phenylphosphine oxide and 4-methoxyphenol. The polymers exhibited inherent viscosities of 0.57–0.75 dl g −1 and glass transition temperatures of 177–213°C. Thermogravimetric analyses showed 5% weight loss in the ranges of 447–471°C in air and 480–512°C in nitrogen. Unoriented thin films exhibited tensile strengths, moduli and break elongations at 23°C of 8.1–11.1 ksi, 275–370 ksi and 42–109%, respectively. Limiting oxygen indices of 0.30–0.33 were calculated based on polymer char residues at 850°C in nitrogen. Phenylphosphine oxide-containing poly(arylene ether)s exhibited excellent resistance to an oxygen plasma environment with weight loss rates of one to two orders of magnitude lower than that of Kapton ® HN. The chemistry, and physical and mechanical properties of these polymers, as well as their oxygen plasma resistance, are discussed.