Abstract: Polymers having improved tenacity and heat resistant properties are prepared by heating a mixture of a 4-acetoxybenzoic acid derivative, a hydroquinone diacetate derivative, a dicarboxylic acid, and a 4-acetoxy-(4-acetoxyphenyl)benzoate derivative in two steps to remove generated acetic acid and form the polymer, which is useful for making fibers, films and molded products.

Abstract: A fire retardant additive for a polyurethane foam comprising a copolymer of:(1) an allyl group containing compound having the formula (CH.sub.2 .dbd.CHCH.sub.2 O).sub.2 P(O)A, where A is either OR or R, R being a vinyl group, an allyl group, a C.sub.1 -C.sub.10 alkyl group or an aryl group;(2) at least one bis(hydrocarbyl)vinylphosphonate having the structure: ##STR1## wherein X is selected from the group consisting of hydrogen, halogen, cyano, aryl, C.sub.1 -C.sub.18 alkyl, and ##STR2## wherein R and R' are hydrocarbyl and substituted hydrocarbyl groups which can be the same, different or conjoint; and(3) at least one optional third comonomer selected from the group consisting of the vinyl and vinylidene halides, the alpha olefins, vinyl esters of carboxylic acids, C.sub.1 -C.sub.20 alkyl esters of acrylic and methacrylic acid, ethylenically unsaturated dicarboxylic acids, the corresponding anhydrides thereof and the C.sub.1 -C.sub.