Chiang Mai Journal of Science

P(VDF/TrFE/CTFE)  terpolymers  are  electrostrictive,  converting  electrical  energy  to mechanical  energy by  a  transformation  between  ferroelectric  and  paraelectric  phases. This transformation occurs as a result of  a change in conformation of  the polymer backbone. In this  study,  Dynamic  IR  Linear  Dichroism  (DIRLD)  spectroscopy, which  provides  useful information  on  the  local  structure  of   a  polymer  that  interacts  and  responds  to  external perturbation, was used to measure the time-dependent IR response to sinusoidal strain. The major advantage of  this technique over normal FTIR experiments is that it provides information correlating the IR response of each functional group with the applied mechanical strain and allows a comparison to the IR response of  other functional groups. The DIRLD spectra of isotropic and uniaxially drawn (3:1 ratio) films were studied. A sinusoidal strain was applied to a  film  in  the  direction  parallel  to  the  direction  of   chain  alignment.  Information  about  the reorientation of the electric dipole-transition moments relative to the polarization direction of the infrared beam was obtained. In addition, the dichroic DIRLD spectra were generated. The results obtained from the uniaxially drawn sample provide the time-dependent IR responses, and the relative direction of electric dipole-transition reorientations of functional groups in both amorphous and crystalline domains.