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

Liquid crystalline polymers are currently among the most widely studied classes of polymeric materials. The correlation of mesophase and liquid crystalline polymer molecular structures with observable physico-chemical properties is a major objective. In this work, inverse gas chromatography (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 very 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 liquid crystalline phases. Thus, enthalpies of mixing and solution of probe molecules in the polymer were estimated, and activity coefficients were calculated. From a single i.g.c. experiment, a wide range of information regarding the temperature-dependent properties of a liquid crystalline polymer was obtained.