THE USE OF INVERSE GAS-CHROMATOGRAPHY TO STUDY LIQUID-CRYSTALLINE POLYMERS

Liquid crystalline polymers are currently among the most widely studie d classes of polymeric materials. The correlation of mesophase and liq uid crystalline polymer molecular structures with observable physico-c hemical properties is a major objective. In this work, inverse gas chr omatography (i.g.c.) was used to determine the transition temperatures of a main chain, liquid crystalline, biphenyl-based organic polyester . The transition temperatures determined by using this method agree ve ry well with those determined by other techniques. In addition, the i. g.c. experiment gives physico-chemical parameters for the interaction of probe molecules (saturated and aromatic hydrocarbons) with the liqu id crystalline phases. Thus, enthalpies of mixing and solution of prob e molecules in the polymer were estimated, and activity coefficients w ere calculated. From a single i.g.c. experiment, a wide range of infor mation regarding the temperature-dependent properties of a liquid crys talline polymer was obtained.