Deformation and transformation mechanisms of poly(vinylidene fluoride) (PVF2)

The deformation process and the accompanyingα→β phase transformation of poly(vinylidene fluoride), drawn at 82 to 90 and 130° C, has been characterized by electron microscopy and X-ray and electron diffraction. Micronecking occurs at both draw temperatures, fibrils and mosaic blocks being drawn off the edges of the micronecks. The degree of phase transformation, at the same elongation, is dependent on the draw temperature; at 130° C the majority of the sample remains in theα phase at the natural draw ratio. The phase transformation at both draw temperatures accompanies the transformation from lamellar (block) structure to fibril.