Bending piezoelectricity in SAN and ABS copolymer films

The bending piezoelectric coefficients /spl beta//sub 331/ have been calculated (/spl sim/1.5, 8.3, 10.0 /spl mu/m) for various cases of unstretched and stretched, unpoled and corona poled, films of SAN. For the ABS films the value of /spl beta//sub 331//spl sim/2.6 nC/m was obtained for unstretched and unpoled film, and 4.4 nC/m for corona poled films. A linear relation between /spl beta//sub 331/ and d/sub 31/ for the heat-treated samples indicates that the major contribution to bending piezoelectricity comes from the dipolar polarization.