Mechanical Properties and Dielectric Properties of P(VDF-HFP)/EP Composite Films

Poly(vinylidene fluoride-hexafluoropropylene) [P(VDF-HFP)] and bisphenol A epoxy resin (EP) composite films were prepared by solution casting. The tensile strength of the composite film was enhanced by adjusting the curing conditions of the EP. The results showed that EP dispersed in the form of particles, and at higher content, EP particles mixed with P(VDF-HFP) to form an enrichment zone. A special structure of P(VDF-HFP) epitaxial crystals formed around the enrichment zone. Fourier-transform infrared spectroscopy and x-ray diffraction analyses showed that parts of the non-polar α phase transformed to the weak polarity γ phase after the addition of EP. With the addition of EP, the breakdown strength of the composite film was significantly improved. The energy loss of the composite film was greatly reduced, and the discharge efficiency was remarkably improved.