Thermal behavior of phthalic anhydride bases polyesters: Part II. Influence of the polyol by polyesters synthetized in microwave field

Three phthalic type polyesters with 1,2-propaneglycol (PG), trimethylolpropane (TMP) and glycerin (GLY) were synthetized in a microwave field (500 W). The synthesis time is significant smaller (3–4 h) in comparison with the classical ones (10 h). By TMP and GLY, an anhydride/glycol molar ratio of 1:1.75 was used in order to obtain certainly a linear chain with free OH side groups. The TG/DTG data allow a qualitative estimation of the influence of the polyol on the thermal stability of the synthetized polyesters. By an adequate kinetic analysis using three different kinetic methods, quantitative data on the rate of the thermodegradation were obtained. The estimation of the thermal stability by both thermoanalytical curves and kinetic analysis indicates an increase in the stability (influenced by the glycol) of the order: PG