PYROELECTRIC AND DIELECTRIC-PROPERTIES OF SIDE-CHAIN LIQUID-CRYSTAL POLYMERS

Liquid crystal side-chain polymers (LCP), where the polymer architectu re consists of a polymer backbone, flexible spacers, and mesogenic gro ups, are of considerable interest as they promise desirable electro-ac tive properties, including pyroelectricity and electro-optic display p henomena. Induced polarization in the LCP system remains stable at ord inary temperatures, and therefore these systems are suitable for senso r materials for pyroelectric applications where switching times are le ss important. The dielectric applications of the polarized LCP system are also of importance if they are to be used as thin film electro-act ive devices. This paper reports the results of the dielectric and pyro electric characterizations of six different polymers over a wide range of frequencies and temperatures. To elucidate the effect of a variati on of chemical structure on the macroscopic properties, the structure of the mesogenic moiety was kept constant, and the length of the space r and the size of the polymer backbone were varied.