Synthesis and Characterization of certain Biodegradable Thermotropic Liquid Crystalline Random Copolyesters

A series of high molecular weight copolyesters were prepared from isophthalic acid, 1,4butane diol and sebacic acid/ adipic acid through a two step process of melt polycondensation using titanium tetra butoxide as catalyst. The synthesised random copolyesters were characterised by means of IR, 1H NMR, 13C NMR, gel permeation chromatography (GPC), viscosity measurements, differential scanning calorimetry (DSC), thermogravimetry (TG) and X-ray diffraction (XRD) studies. The effect copolymer composition on the physical and thermal properties, as well as enzymatic degradation was investigated. The enzymatic degradation was performed in a buffer solution with enzyme Candida cylindracea lipase. The phase behaviour of the polymers was studied by differential scanning calorimetry and optical polarising microscopy equipped with a heating stage. The copolyesters exhibit thermotropic liquid crystalline behaviour with nematic texture as observed by optical polarising microscopy.