MODIFICATION OF PHASE-TRANSITIONS IN SWIFT HEAVY-ION IRRADIATED AND MMA-GRAFTED FERROELECTRIC FLUOROPOLYMERS

Ferroelectric poly(vinylidene fluoride) (beta PVDF) and copolymers of vinylidene fluoride-trifluoroethylene (P(VDF/TrFE)) were irradiated wi th swift heavy ions and post-irradiation grafted with methyl methacryl ate (MMA). We have studied the influence of irradiation parameters suc h as the ion fluence, the type of ion and the electronic stopping powe r, on the melting and crystallisation temperatures and on the ferroele ctric to paraelectric phase transition, by DSC measurements. Irradiati on with swift heavy ions lowers the phase transition temperatures. Ion track grafting with MMA reveals two separate PMMA-phases. The graftin g process affects the ferroelectric to paraelectric phase transition i n P(VDF/TrFE) and leads to a strong amorphization of the polymer films . The melting temperature of PMMA-grafted beta PVDF is diminished.