| Abstract: | New phenoxaphosphine-containing polyester-imides were prepared by the interfacial polycondensation of a dichloroformyl-phenoxaphosphine derivative containing a preformed imide ring with five bisphenols. The polymerizations, which were carried out in a chloroform-aqueous sodium hydroxide mixture, afforded polyester-imides with reduced viscosities of 0.60–1.55 dL/g in 61–95% yields. The preformed imide ring did not undergo hydrolysis under the polymerization conditions. Several of the polymers were soluble in chloroform and could be cast into flexible and transparent films. The phenoxaphosphine-containing polyester-imides have good thermal properties, exhibiting little decomposition below 400°C. They appear to be more thermally stable than phenoxaphosphine-containing polyesters, but are not as thermally stable as the corresponding polyimides and polyamide-imides. The order of thermal stability for phenoxaphosphine-containing polymers in air is polyimide ? polybenzoxazole > polyamide-imide ? polybenzimidazole > polyester-imide > poly-1,3,4-oxadiazole ? polyamide > polyester. The polyester-imides exhibited self-extinguishing behavior. |
