Abstract: Polymer alloys of a phosphorus-containing polymer component having the formula: ##STR1## WHEREIN X is hydrogen or halo; Z and Z' are each hydrogen or a phosphonate group PO(OR)(OR.sub.1) in which R and R.sub.1 are each alkyl or aryl, but are not both hydrogen, Y is a bivalent radical from an ethylenically unsaturated monomer copolymerized with styrene, and m, m', n, n' and p are zero or integers as specified; and a second polymer component compatible with and alloyed with the phosphorus-containing polymer component, the second component being a cellulose ester, or a polystyrene or unsaturated polyester resin. Polymer alloys thus constituted are particularly useful as fire-retardant and flame-resistant materials, and as membranes useful in the separation of solvents exhibiting differential permeabilities therethrough.

Abstract: The present disclosure relates to improved polymeric materials and to a process for preparing same, which comprises blending suitable polymers into novel polymeric alloys. The disclosure further relates to novel fire-retarding and flame-resistant materials comprising such polymeric alloys and to novel membrane materials and membranes, adapted to provide novel processes of separation based on membrane technology. The novel polymeric alloys comprise commercially available polymers, blended with novel polymeric phosphonates of the general formula: ##STR1## WHEREIN: M, M', N, N' ARE ZERO OR ANY INTEGER, P IS AN INTEGER HIGHER THAN 10X designates a hydrogen atom halogen atom or a phosphorusContaining groupY designates a CH.sub.2 CHCl or CH.sub.2 CCl.sub.2 groupZ and Z' designates H or a phosphonate group - PO(OR') (OR") (at least one being a phosphonate group), wherein R and R' are alkyl or aryl groups.