A thermogravimetric study on thermal degradation of polyethylene

In the present work it is shown that random scission degradation does not follow rigorously first-order kinetics. A relation for determining reaction order was therefore established to avoid blind use of first-order reaction model. Reaction order of the dynamic degradation of a high-density polyethylene was thus determined to be 0.55. Isothermal degradation of the polyethylene was found to have the same reaction order. Furthermore, it is observed that the mean value of activation energies, estimated by the isoconversional method, of the dynamic degradation was similar to the value of the isothermal degradation.