A New Discovery of Microphase Separation Initiating In the Induction Period of Polymer Crystallization : characteristic wavelengths at high temperatures (FUNDAMENTAL MATERIAL PROPERTIES-Polymer Materials Science)

Abstract

On the basis of the previous new discovery that a spinodal decomposition type of microphase separation occurs during the induction period for glass crystallization when a polymer is crystallized at low temperatures just above the glass transition temperature, the effect of crystallization temperature on the characteristic wavelength has been studied using poly(ethylene terephthalate) (PET) because this is an important factor for spinodal structures determining the whole skelton of higher-order structure of crystalline polymers. For melt crystallization when PET is crystallized directly from the melt at high temperatures below the melting point, the characteristic wavelength is obtained to be a few micrometers which is two orders of magnitude larger than that for the glass crystallization. This may provide a possible elucidation for the large difference in size and density of spherulites between the glass and melt crystallization.