THERMOMECHANICAL AND ELECTROOPTICAL PROPERTIES OF POLYMER-DISPERSED LIQUID-CRYSTAL FILMS

We have observed a strong dependence of the electro-optical properties of polymer dispersed liquid crystal (PDLC) films on temperature. One plausible explanation for this dependence is the thermal expansion of the films. We investigated the thermal expansion of various PDLC films using a thermal mechanical analyser (TMA). As the temperature increas ed, the films expanded and their droplet size decreased, and their con trast, response time, and hysteresis changed simultaneously. We observ ed obvious changes of thermal expansion coefficient of the films. We s tudied the qualitative relationship between thermo-mechanical properti es and electrooptical properties. The thermal expansion of PDLC films could be adjusted by changing the degree of cross-linking of the polym er.