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

Homopoly(esters) similar to those of liquid crystalline poly(oxybenzoate) w ere 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 a cid were investigated at 245 degreesC, 255 degreesC and 265 degreesC. A sec ond-order rate model which can analyze kinetic parameters of two different kinetic regimes has been used to interpret the experimental data for 20 dif ferent experimental sets. It is observed that the correlation coefficient b etween observed and calculated values range between 0.98 and 0.99 confirmin g the validity of the said model. The nature of the kinetic behaviour in th e two regimes were found to be independent of catalyst type and concentrati on. Second-order rate law describes the entire kinetic behaviour of this sy stem almost adequately. The Arrhenius constants and activation energy param eters for this system have been reported. Oligomers isolated from the homop oly(esters) are expected to be liquid crystalline in nature. (C) 2001 Elsev ier Science Ltd. All rights reserved.