Poly(arylene ether)s Containing Phenylphosphine Oxide Groups

Abstract

As part of a NASA program to develop materials for potential future space applications, poly(arylene ether)s containing phenylphosphine oxide groups were prepared and characterized. The polymers were synthesized by the aromatic nucleophilic displacement reaction of two isomeric bisphenols, 2,5- dihydroxyphenyldiphenylphosphine oxide and bis(4-hydroxyphenyl)phenylphosphine oxide, with activated aromatic difluorides in the presence of anhydrous potassium carbonate in N,N-dimethylacetamide at 155 'C. The polymers exhibited inherent viscosities from 0.35 to 1.00 dL g- 1 and glass transition temperatures from 160 to 249 'C. Thermogravimetric analyses showed 5% weight loss ranging from 382 to 479 'C in air and 377 to 505 'C in nitrogen. Unoriented thin films exhibited tensile strengths, moduli, and break elongations at 23 'C of 49-94 MPa, 2.3-3.4 GPa, and 6-41%, respectively Limiting oxygen indices from 18-32 were calculated based on polymer char residues at 850 'C in nitrogen. The polymers exhibited relatively low solar absorptivities ranging from 0.04 to 0.16 and thermal emissivities ranging from 0.48 to 0.63. The chemistry, physical, and mechanical properties of these polymers are presented herein.