This letter reports the ferroelectric and electromechanical properties of a class of ferroelectric polymer, poly(vinylidene-fluoride–trifluoroethylene–chlorotrifluoroethylene) terpolymer, which exhibits a slim polarization hysteresis loop and a high electrostrictive strain at room temperature. The dielectric and polarization behaviors of this terpolymer are typical of the ferroelectric relaxor. The x-ray and Fourier transform infrared results reveal that the random incorporation of bulky chlorotrifluoroethylene (CTFE) ter-monomers into polymer chains causes disordering of the ferroelectric phase. Furthermore, CTFE also acts as random defect fields which randomize the inter- and intrachain polar coupling, resulting in the observed ferroelectric relaxor behavior.

No abstract

No abstract

In this paper, the effect of high-energy electron irradiation on the transitional and electromechanical responses of PVDF-TRFEIPMMA (poly (vinylidene fluoride-trifluoroethy1ene)l polymethylmethacrylate) blend films is investigated in the light of a recent finding of large electrostrictive strain and high electromechanical response of PVDF-TRFE copolymer films after high-energy electron irradiation. Due to the decrease in crystallinity, both the dielectric and polarization responses were found to decrease with PMMA content. Interestingly, the presence of PMMA is found to affect the crystal-amorphous interface properties strongly in irradiated polyblend films. The field-induced strain which could be due to electrostriction and Maxwell stress for a blend system is found to come mainly from electrostriction. At room temperature, the contribution to the total strain from the Maxwell stress is found to be ~2 0 % while this contribution increases markedly with increasing temperature, especially for 7 %wt PMMA polyblend films.

No abstract