Abstract: The present invention relates to thermoplastic polymer compounds comprising a blend of a chlorinated polyvinyl chloride and an impact modifier containing a polyorganosiloxane and polyalkyl(meth)acrylate. The novel thermoplastic compound has improved stability and toughness and exhibits a low rate of heat release.

Abstract: A flexible polyacid containing at least one phosphorus and/or halogen-containing component may be prepared readily by (1) mixing together in bulk, solution or dispersion a polyacid and at least one of six hereinafternamed components and (2) drying or conditioning the mixture. The component may be selected from the group consisting ofA. at least one di(polyoxyethylene)hydroxymethyl phosphonate having the formula ##EQU1##HOCH.sub.2 P(O)[O(C.sub.2 H.sub.4 O).sub.k H].sub.2wherein k is from 1 to 5,B. at least one compound having the formula ##EQU2## wherein the sum of m and n is from 1 to 35 (C) tetrakis (hydroxymethyl)phosphonium chloride [(HOCH.sub.2).sub.4 PCl], (D) a mixture of from about 75% to about 100% by weight 2,2-bis-(bromomethyl)-1,3-propanediol, from about 0% to about 10% by weight monobromoneopentyl triol, and from about 0% to about 20% by weight tribromoneopentyl alcohol (E) diethyl ethyl phosphonate [C.sub.2 H.sub.5 P(O)(OC.sub. 2 H.sub.5).sub.2 ], and (F) a compound having the formula (RO).sub.