Thermal degradation of poly(p-phenylenebenzobisoxazole) and poly(p-phenylenediamine terephthalamide) fibres

Abstract

This study investigates the thermal stability of poly(p-phenylenediamine-terephtalamide) (PPT) and poly(p-phenylenebenzobisoxazole) (PBO) fibres. Excellent behaviour of PBO is shown in comparison to that of PPT. The thermal stability (under pyrolytic or thermo-oxidative conditions) of PBO is 150 °C higher than that of PPT. Moreover, the strong influence of oxygen, which plays the role of an initiator of degradation, on the degradation of fibres is shown. Using the invariant kinetic parameter (IKP) method, it is shown that the degradation rate of PBO is strongly reduced in comparison with that of PPT. It provides a simulation of the ‘fuel flow’ able to feed the flames, which can explain the high fire performance of PBO compared to PPT. © 2001 Society of Chemical Industry