Conformational and crystallographic changes occurring in polyvinylidene fluoride during the production of D-E hysteresis loops

When polarization hysteresis loops are produced for biaxially oriented polyvinylidene fluoride, significant changes between successive loops are found to occur. These changes are most noticeable during the first few cycles and are shown, with the aid of infrared spectroscopy, to be the result of changes in chain conformation and consequent crystal structure in the material. Movement of free charge appears to play a negligible role in the changes observed.