NOVEL CHARACTERISTICS OF POLY(1,6-HEPTADIYNE) DERIVATIVES WITH LONG SIDE-CHAINS IN LIQUID-CRYSTALLINE PHASE

Poly(1,6-heptadiyne) derivatives substituted with long side chains con taining mesogen units such as poly(bis(4-methoxy-4'-hexyloxybiphenyl)d ipropargyl malonate) (PMHBDPM) exhibit unique characteristics typical to both liquid crystal and conducting polymer. PMHBDPM exhibits smecti c A phase in consistent with temperature dependence of X-ray diffracti on, Two stages of electrochemical doping corresponding to the charge t ransfers between dopants and polymer main chain and also between dopan ts and the core of the mesogen unit in the side chain are observed. Di ffusion coefficient of dopants also exhibits drastic change at the pha se transition between smectic A phase and isotropic phase. These chara cteristics have been discussed in terms of molecular orientations of b oth polymer main chains and substituted side chains, Unique dielectric properties and X-ray diffraction characteristics have been observed i n a mixture of PMHBDPM with ferroelectric liquid crystal of low molecu lar weight.