Aromatic polyamides

Kinetics of the initial degradation of poly(1,3-phenylene isophthalamide) and of poly(chloro-2, 4-phenylene isophthalamide) has been studied by TG in inert as well as oxidative atmospheres. The information derived from the kinetic data is in agreement with our earlier reported studies on the degradation mechanism of these polyamides. The difference-differential method of Freeman-Carroll is shown to have problems when applied to high-char forming polymeric materials. The isoconversion method of Ozawa involving simple computations based on a particular reaction extent, is considered suitable for studying the complex degradation behavior of high-temperature and high-char forming polymer systems. Using this procedure, an activation energy of 215–230 kJ/mole is obtained for the initial degradation of the studied aromatic polyamides in inert and oxidative environments.