Radiation-Induced Changes in the Dielectric Response of Poly(Vinylidene Fluoride) Type Polymers

Abstract

High and dispersive dielectric response, characteristic of the relaxor state, was observed in ferroelectric P(VDF/TrFE)(50/50) copolymers irradiated with 1.0 MeV and 1.5 MeV electrons. Relaxor-like behaviour of the copolymer is a result of overlapping of the dielectric anomaly characteristic of the glass transition and that related to the Curie point, which is shifted downwards by electron irradiation. The results of ESR, IR and NIR Raman spectroscopy studies of the radiation damage to P(VDF/TrFE)(50/50) show that radiation-induced irreversible transformation of the ferroelectric copolymer to the relaxor state is related to the existence of polar clusters, consisting of a variety of short range coherence of trans-conformation, stabilized by random fields of C=C and conjugated C=C bonds.

Keywords:

• Poly(Vinylidene fluoride/trifluoroethylene) copolymer
• Ferroelectric polymer
• Ferroelectric relaxor
• Polar clusters
• Dielectric relaxation
• Electron irradiation
• Free radicals