PIEZOELECTRIC PROPERTIES OF ORIENTED FILMS OF POLY(GAMMA-METHYL D-GLUTAMATE)

in the reported experiments, the dynamic piezoelectric stress constant e//2//5 of drawn films of poly( gamma -methyl D-glutamate) (PMDG) cast from solutions in alpha -helix-promoting solvents 1,2-dichlorethane (DCE) and chloroform and from the nonhelicogenic solvent dichloroacetic acid (DCA) was measured from minus 180 degree C to 200 degree C at 110 Hz. The drawn and annealed films cast from chloroform show a small peak for the real part of piezoelectric stress constant minus e prime //2//5 in the temperature range of the mechanical alpha //2-crystalline relaxation, which is caused by the distortion motion of the backbone chain of the alpha -helix. Drawn films cast from DCE show the peak of the real part of the piezoelectric stress constant, whose magnitude decreases in the range of the mechanical alpha //1-crystalline relaxation or the beta -relaxation processes. From extensive experimental data it is concluded that the piezoelectric properties of PMDG arise from distortion of the backbone chain of the alpha -helix induced by applied strain.