Transverse strain responses in the electrostrictive poly(vinylidene fluoride–trifluorethylene) copolymer

Abstract

A large transverse electrostrictive strain S1 with a high elastic strain energy density is observed along the drawing direction in the stretched poly(vinylidene fluoride–trifluorethylene) copolymer film under a proper electron irradiation treatment condition, which results in a ratio of |S1/S3| larger than 1 where S3 is the longitudinal strain. In contrast, unstretched films generate a relatively small transverse strain with a small ratio of |S1/S3| (∼0.25). Hence, in this copolymer system, the ratio of |S1/S3| can be varied over a broad range. In addition, a large volume strain, which amounts to about half of the longitudinal strain, is observed in the films investigated.