EARLY AND LATE-STAGE PHASE-SEPARATION DYNAMICS OF POLYSTYRENE/POLY(METHYL METHACRYLATE-STAT-CYCLOHEXYL METHACRYLATE) BLENDS

The dynamics of phase separation after a temperature jump from the one phase region into the two phase region has been studied on blends of polystyrene (PS) and poly(methyl methacrylate-stat-cyclohexyl methacrylate) (PMsC) on different substrates. This system shows a lower critical solution temperature (LCST). The phase separation process followed the mechanism of spinodal decomposition, and the early and late stages could be resolved by using small angle light scattering(SALS). While the early stage could be described by the theory of Cahn and Hilliard, the time dependence of the scattering during the later stages of demixing could be described by power laws. From deviations of Porod's law the interface thickness between two phases was estimated and a new scaling function was proposed.