Relation between microstructure and glass transition temperature of poly[(methyl methacrylate)-co-(ethyl acrylate)]

The glass transition temperature of a series of samples of the poly[(methyl methacrylate)-co(ethyl acrylate)l copolymer, synthesized at low conversion , were calculated theoretically using the equations of Barton and Johnston. The values obtained are more precise when the probabilities of the composi tional diads are derived from the C-13 NMR data instead of the classical me thod utilizing reactivity ratios. This can be observed more clearly when th e copolymer samples are synthesized at high conversion. Introduction of con figuration (tacticity) at the diad level confirms the above observations an d slightly improves the calculated values of Tg compared to the initial for mulae which were only taking into account the compositional sequences of th e copolymer. (C) 2001 Society of Chemical Industry.