Ferroelectric homopolymer PVF2 and P (VDF-TrFe) copolymers

The ferroelectric and piezoelectric properties of PVF2 polymer are summarized. The physical properties of PVDF piezoelectric film are given. Polarization of PVF2 is described. Ferroelectric polarization of VF2/C2F3H copolymers; influence of X rays on PVF2 elements; and the effects of uniaxial compression on the piezoelectric activity of PVF2 are discussed. The performance of PVF2 transducers is compared with PZT transducers. The maximum energy input achieved in PVF2 is 10 times in excess of the energy input attainable in a PZT ceramic in which the coefficiency of electromechanical conversion is 10 times higher. Considering that for PVF2 acoustic matching to propagating media is better than for PZT and that polymer properties (easy handling, surface, thickness, lightness , random shapes) are important, it is suggested that PVF2 can fill the gaps left by PZT in loudspeakers and earphones, hydrophones, and probes used for echography.