OXYGEN PLASMA RESISTANT PHENYLPHOSPHINE OXIDE-CONTAINING POLY(ARYLENEETHER)S

Phenylphosphine oxide-containing poly(arylene ether)s were prepared by the aromatic nucleophilic displacement reaction of a new phenylphosph ine oxide-containing bisphenol with activated aromatic difluorides in the presence of anhydrous potassium carbonate in N,N'-dimethylacetamid e at 155-degrees-C or in sulfolane at 200-degrees-C. The phenylphosphi ne oxide-containing bisphenol was prepared in two steps from bis(4-flu orophenyl)phenylphosphine oxide and 4-methoxyphenol. The polymers exhi bited inherent viscosities of 0.57-0.75 dl g-1 and glass transition te mperatures of 177-213-degrees-C. Thermogravimetric analyses showed 5% weight loss in the ranges of 447-471-degrees-C in air and 480-512-degr ees-C in nitrogen. Unoriented thin films exhibited tensile strengths, moduli and break elongations at 23-degrees-C of 8.1-11.1 ksi, 275-370 ksi and 42-109%, respectively. Limiting oxygen indices of 0.30-0.33 we re calculated based on polymer char residues at 850-degrees-C in nitro gen. Phenylphosphine oxide-containing poly(arylene ether)s exhibited e xcellent resistance to an oxygen plasma environment with weight loss r ates of one to two orders of magnitude lower than that of Kapton(R) HN . The chemistry, and physical and mechanical properties of these polym ers, as well as their oxygen plasma resistance, are discussed.