Thermal degradation of UHMWPE

The thermal behaviour of ultra-high molecular weight polyethylene (UHMWPE) of different molecular weights was examined by thermal analysis methods. The melting temperatureT_m and the heat of melting H were measured by the DSC method. The thermooxidative degradation process was investigated by using a MOM Q-1500 D derivatograph at various heating rates in air atmosphere. The initial decomposition temperatureT_i was determined from the TG curves, and other characteristic temperatures of decomposition were calculated. It was found thatT_m and H are higher for UHMWPE than those for HDPE, i.e. 146C and 195 J g^–1 for UHMWPE as compared with 133C and 166 J g^–1 for HDPE. The thermal behaviour of the investigated UHMWPE samples is not significantly influenced by molecular weight.