THERMAL-DEGRADATION OF UNMWPE

The thermal behaviour of ultra-high molecular weight polyethylene (UHM WPE) of different molecular weights was examined by thermal analysis m ethods. The melting temperature T-m and the heat of melting Delta H we re measured by the DSC method. The thermooxidative degradation process was investigated by using a MOM Q-1500 D derivatograph at various hea ting rates in air atmosphere. The initial decomposition temperature T- i was determined from the TG curves, and other characteristic temperat ures of decomposition were calculated. It was found that T, and Delta H are higher for UHMWPE than those for HDPE, i.e. 146 degrees C: and 1 95 J g(-1) for UHMWPE as compared with 133 degrees C and 166 J g(-1) f or HDPE. The thermal behaviour of the investigated UHMWPE samples is n ot significantly influenced by molecular weight.