EFFECT OF CRYSTALLIZATION TEMPERATURE ON THE CRYSTALLINE PHASE CONTENT AND MORPHOLOGY OF POLY(VINYLIDENE FLUORIDE)

The effect of temperature on the crystallization of alpha, beta, and gamma phases of PVDF from dimethylacetamide (DMA) solution was studied. Variation in the crystallinity content of these three phases was obtained as a function of temperature using infrared spectroscopy, differential scanning calorimetry (DSC) and x-ray diffraction techniques. Such variation is related to the dependence of the crystallization rate of each phase with temperature, and allowed a better understanding of some results found in the literature about the crystallization and interconversion of these phases. Micrographs of samples present morphologies that corroborate with the proposed explanations. (C) 1994 John Wiley & Sons, Inc.