Studies on Biphase Behaviour of Certain Thermotropic Liquid Crystalline Copolyesters

Four Thermotropic Liquid Crystalline (TLC) random copolyesters were prepared by direct polycondensation of two diols and oxaloyl chloride in o-dichlorobenzene solution. The structures of the repeating units of the synthesised polyesters were examined by FT-IR and PMR spectral data. The thermal transition temperatures were determined by differential scanning calorimetry. The LC behaviour of these polymers were studied by optical polarising microscopy in conjunction with WAXD studies. Three of these polyesters exhibited interesting biphase behaviour. The polyester containing 2,5-ditertiarybutylphenylene rings in the main chain exhibited discotic behaviour.