Quantitative analysis of structural, relaxational and electrostrictive properties of PVDF-TRFE/PMMA films irradiated with high-energy electrons

In this paper, the effect of high-energy electron irradiation on the transitional and electromechanical responses of PVDF-TRFE/PMMA (poly (vinylidene nuoride-trinuoroethylene)/polymethylmethacrylate) blend films is investigated in the light of a recent finding of large electrostrictive strain and high electromechanical response of PVDF-TXFE 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 <20% while this contribution increases markedly with increasing temperature, especially for 7 %wt PMMA polyblend films