TG-DTA FT-IR METHOD FOR ANALYZING THERMAL-DECOMPOSITION MECHANISM OF POLYESTERS

An attempt to estimate the thermal decomposition mechanism of polymers using the simultaneous TG-DTA/FT-IR system was summarized. The librar y search of FT-IR spectra at various temperatures and of the subtracti on spectrum obtained by subtracting the spectra at different temperatu res were used to determine the types of evolved gases from poly(ethyle ne terephthalate) and poly(butylene terephthalate) at given stages of decomposition. The quantitative analysis of evolved gases was carried out using the specific gas profiles at the specific absorption band. T he kinetic parameters were estimated from both TG and spectroscopic cu rves measured at various heating rates.