Crystalline Structure and Phase Transformation in Powder Processing of Polyvinylidene Fluoride with Fillers

Abstract Structural investigations have been carried out in powder processed polyvinylidene fluoride containing various amounts of titanium dioxide and lead monoxide as fillers. The crystallinity was found to increase significantly at very low filler concentration (<3 percent) while it decreased monotonically with increasing filler concentrations above 5 percent. The phase transformation in the crystal structure was also noticed especially after sintering and the formation of beta phase was favourable in samples containing lead oxide. These various findings were also confirmed by infrared absorption studies and explained on the basis of deformation of the polymer during compaction together with preferential nucleation by the filler during the sintering step of the powder processing technique.