Glass transition temperature of mixtures of poly(methyl methacrylate-co-ethyl acrylate)

DSC thermogrammes of mixtures of poly(methyl methacrylate-co-ethyl acrylate), PMMA-EA, of different microstructure of macromolecular chains, exhibit two glass transition temperatures, Tg, indicating the presence of two phases. In one phase the copolymer chains are compatible with long blocks of ethyl acrylate and the second phase is very rich in long chains of methyl methacrylate. Based on the C-13 NMR results for compositional diads distribution and DSC data, a miscibility line can be drawn when the results are presented in a form of a triangular diagram.