Phase Behaviour of Poly(styrene-co-methacrylic acid)/Poly(styrene-co-N,N-dimethylacrylamide)/Poly(styrene-co-4-vinylpyridine) Ternary Blends by DSC and FTIR

摘要

we have investigated by DSC and FTIR the miscibility and phase behaviour ofbinary and ternary blends of different ratios of polystyrene-co-methacrylic acid)containing 15 mol% of methacrylic acid (SMA15) with poly(st)%rene-co-N,N-dimethyl-acrylamide) containing 17 mol% of N,N,-dimethylacrylamide (SAD-17) and poly(styrene-co-4-vinylpyridine) containing 15 mol% of 4-vinylpyridine. SMA15 is miscible with bothSAD17 and S4VP15 and interacts more strongly with S4VP15 than with SAD17 asevidenced by the positive deviations from linear average line observed with theseblends and the appearance of new bands in the 1800-1550 cm-1 region. This behaviouris known as AK effect. The FTIR study confirms that though the specific intermo-lecular interactions that occurred with each pair of the SMA15/S4VP15 and SMA15/SAD17 binary components are of different strength, they still exist in the ternaryblend. Even though the three binary polymer pairs are individually miscible, theternary system of SMA15/S4VP15/SAD17 exhibits only partial miscibility with smallloop of immiscibility due to a significant AK effect. These results obtained by DSC andFTIR are in a fair agreement with theoretical prediction applying the Painter-Colemanassociation model.