Modification of phase transitions in swift heavy ion irradiated and MMA- grafted ferroelectric fluoropolymers

Ferroelectric poly(vinylidene fluoride) (β PVDF) and copolymers of vinylidene fluoride-trifluoroethylene (P(VDF/TrFE)) were irradiated with swift heavy ions and post-irradiation grafted with methyl methacrylate (MMA). We have studied the influence of irradiation parameters such as the ion fluence, the type of ion and the electronic stopping power, on the melting and crystallisation temperatures and on the ferroelectric to paraelectric phase transition, by DSC measurements. Irradiation with swift heavy ions lowers the phase transition temperatures. Ion track grafting with MMA reveals two separate PMMA-phases. The grafting process affects the ferroelectric to paraelectric phase transition in P(VDF/TrFE) and leads to a strong amorphization of the polymer films. The melting temperature of PMMA-grafted β PVDF is diminished.