Technical University of Hamburg-Harburg, Polymer and Composites Group, Hamburg, FRG
Polymer Science and Engineering Department, University of Massachusetts, Amherst, Massachusetts, USA
Abstract:
Highly oriented melt drawn films of poly(vinylidene fluoride) (PVDF) and blends of poly(vinylidene fluoride) and poly(methyl methacrylate) (PMMA) have been studied by transmission electron microscopy, electron diffraction and infra-red spectroscopy. Infra-red spectra show the second moment of the orientation function for PVDF samples to be greater than 0.94. Using such a sample, the transition dipole directions relative to the chain axis have been calculated. Electron microscopic studies of the PVDF/PMMA blends show a transformation for pure PVDF from a lamellar morphology to a mixture of lamellar and needle-like crystals for the 80/20 blend. The 60/40 blend shows a pure needle-like morphology. The β phase content for this blend is dependent upon the composition and thermal history. An increase in the β phase content is observed with the addition of PMMA. After annealing at 110°C, the 50/50 blend shows a lamellar β phase morphology. A significant increase in the segmental orientation of PVDF is also observed.