Thermotropic polymers: synthesis and kinetic analysis of homopoly(esters)

Homopoly(esters) similar to those of liquid crystalline poly(oxybenzoate) were prepared by acidolysis of the monomer methyl hydroquinone diacetate and terephthalic acid at equal mole concentrations. The kinetics of catalyzed and uncatalyzed acidolysis of the hydroquinone diacetate and terephthalic acid were investigated at 245°C, 255°C and 265°C. A second-order rate model which can analyze kinetic parameters of two different kinetic regimes has been used to interpret the experimental data for 20 different experimental sets. It is observed that the correlation coefficient between observed and calculated values range between 0.98 and 0.99 confirming the validity of the said model. The nature of the kinetic behaviour in the two regimes were found to be independent of catalyst type and concentration. Second-order rate law describes the entire kinetic behaviour of this system almost adequately. The Arrhenius constants and activation energy parameters for this system have been reported. Oligomers isolated from the homopoly(esters) are expected to be liquid crystalline in nature.