Miscibility of solution-chlorinated polyethylene with poly(α-methylstyrene-co-acrylonitrile)

Statistical copolymers of a-methylstyrene and acrylonitrile (MSAN) form single-phase blends with solution-chlorinated polyethylene within a restricted composition range, even though no combination of the corresponding homopolymers is miscible. The phase behavior can be successfully described using the general mean-field expression which predicts miscibility on the basis of the intramolecular interactions of the comonomers. By deriving the absolute value of one of the six system interactions from a subsidiary determination of the miscibility limits of poly(methylmethacrylate) in MSAN, values of all the remaining interaction parameters have been determined using a novel phase boundary-fitting technique.