MISCIBILITY PHASE-DIAGRAMS OF THE MIXTURES OF SIDE-ON SIDE-CHAIN LIQUID-CRYSTALLINE POLYMERS AND LOW MOLAR-MASS LIQUID-CRYSTALS

Miscibility phase diagrams of mixtures of a side-on side-chain liquid crystalline polymer (s-SCLCP) and low molar mass liquid crystals have been investigated experimentally and theoretically. The theoretical ca lculation on equilibrium phase diagrams of binary nematic mixtures inv olves a combination of the Flory-Huggins (FH) free energy for isotropi c mixing in conjunction with the Maier-Saupe (MS) free energy for nema tic ordering of the mesogenic units. This combined FH-MS theory predic ts a variety of phase diagrams depending on relative strength of cross -interaction between two dissimilar mesogens to that in the same speci es. The s-SCLCP synthesized is polyacrylate with a mesogenic side grou p connected by a butyl spacer. The temperature-composition phase diagr ams of the mixtures of s-SCLCP and eutectic low molar mass liquid crys tal (E44 and E48) have been established by a cloud point method. The c alculated phase diagrams are found to accord well with the experimenta l phase diagrams.