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The dependence of the kinetics of crystallization and melting behavior in isotactic polystyrene/poly-o-chlorostyrene-co-p-chlorostyrene (iPS /P( o-CIS-co-p-ClS) blends on tempera­ture, thermal history, and blend composition has been investigated. The crystallization rate at a given temperature and copolymer composition decreases with increasing copolymer content in the blend when the samples are premelted. These effects can be ascribed to the reduction of mobility of the crystallizable chains due to the presence of the copolymer and to the decrease in the number of heterogenous iPS nuclei as a result of the premelting process. The Avrami exponent values and the analysis of the blend morphology …

The miscibility ofbisphenol-A polycarbonate (PC) and poly(styrene-co-methacrylic acid) [P(S-MAA)] was investigated by differential scanning calorimetry (d.s.c.) and dynamic mechanical thermal analysis (d.m.t.a.). They seem to be partially miscible in solution-cast film, but to be immiscible in melt blend. In solution cast blends, they are miscible in a limited range of composition; at fraction of P(S-MAA) > 70 %. Miscibility of the ternary system consisting of PC, P(S-MAA ), and poly(styrene-butyl acrylate) [P(S-BA)] was also examined. The compatibility was enhanced by adding small amounts of P(S-BA) block copolymer.