Network structure in poly(vinylidene fluoride-trifluoroethylene) electrostrictive films

Recent studies of electron-irradiated copolymers of vinylidene fluoride and trifluoroethylene have demonstrated the potential for achieving a large electrostrictive response in these materials. Since the principal effect of the radiation is network formation, alternative methods of achieving improved electromechanical properties are available. In this letter, we use a two-solvent swelling technique to quantify the polymer-solvent interaction parameter for the copolymer networks. This enables determination of their crosslink densities, along with a measure of the degree of degradation accompanying radiolysis. Copolymer networks were then prepared chemically using organic peroxide. These networks were found to be similar to the radiation-crosslinked materials, both in the extent of degradation and with respect to the Curie temperature and crystalline melting behavior. The latter are crucial to the development of better electrostrictive properties. (C) 2001 American Institute of Physics.