CRYSTALLIZATION AND MELTING STUDIES ON POLY(ETHYLENE OXIDE) /POLY(METHYL METHACRYLATE) MIXTURES.

The melting and crystallization behaviours in mixtures of monodisperse fractions of PEO and PMMA have been studied as a function of composition and molecular weight of each component. Crystal annealing during crystallization and heating prohibited a reliable evaluation of the equilibrium melting point and cast serious doubts on the determination of the interaction parameter via a melting point depression analysis. To describe the measured radial growth rates in the range 10-60 degree C, it is proposed a kinetic equation that takes into account the thickness of the crystalline lamellae, a cooperative diffusion coefficient and the free energy for the formation of secondary crystal nuclei in a mixture.