Kinetics of thermal degradation of char‐forming plastics from thermogravimetry. Application to a phenolic plastic

Abstract

A technique was devised for obtaining rate laws and kinetic parameters which describe the thermal degradation of plastics from TGA data. The method is based on the inter‐comparison of experiments which were performed at different linear rates of heating. By this method it is possible to determine the activation energy of certain professes without knowing the form of the kinetic equation. This technique was applied to fiberglass‐reinforced CTL 91‐LD phenolic resin, where the rate law ‐ (1/w_e)(dw/dt) = 10¹⁸ e^−55,000/RT [(w ‐ w_f)/w₀,]⁵, nr.⁻¹, was found to apply to a major part of the degradation. The equation was successfully tested by several techniques, including a comparison with constant temperature data that were available in the literature. The activation energy was thought to be correct within 10 kcal.