Effect of Temperature and Atmosphere on the Thermal Degradation of Polyethylene

In this paper, a time-sweep rheometry method was used to evaluate the thermal degradation of a linear low density polyethylene. For this purpose, the rheometry was performed by time-sweep method in the air and nitrogen atmosphere. Storage modulus values were reported as a function of the time. According to the results, this method had a good repeatability. No degradation was observed under nitrogen atmosphere. The results showed that rheometry in presence of air caused a faster and more severe degradation of polyethylene. Higher temperatures shifted forward the onset of the degradation and caused the increase in the slope of the storage modulus-time curve