Poling Behavior and Optical Absorption of Partially Dehydrofluorinated and Uniaxially Stretched Polyvinylidene Fluoride

Abstract

Polyvinylidene fluoride was dissolved together with solid sodium hydroxide as catalyst in a dimethylsulfoxide/acetone mixture and moderately dehydrofluorinated. The dehydrofluorination leads to a partial degradation of the fluorohydrocarbons, and in particular to main-chain scission and to formation of carbon double or triple bonds. This enhances the absorption at UV-vis frequencies. The degradation process also generates a large amount of excess charges in the polymer, which influence the electrical polarization behavior of the dehydrofluorinated polymer. Uniaxial stretching of moderately dehydrofluorinated polyvinylidene fluoride leads to films in a polar phase. Dipole polarization in the degraded and stretched films is demonstrated by means of switching experiments.