Thermal degradation of crosslinked high density polyethylene

Thermal degradation of crosslinked high density polyethylene (HDPE) has bee n investigated by the thermal and spectroscopic methods for development of HDPE as a thermal energy storage material. HDPE was crosslinked to 10 Mrad by electron beam irradiation. For thermal degradation studies, the crosslin ked HDPE was kept in air or vacuum at 150 degrees C for 1000 h. The crossli nked HDPE was severely degraded in air but almost no degradation was observ ed in vacuum. Analysis by DSC, XRD and C-13 NMR spectroscopy showed that th ermal degradation was correlated with the crystallinity of the crosslinked HDPE. The crystallinity completely disappeared and the amorphous phase incr eased with thermal degradation in air. The thermal stability and charge/dis charge performance of the crosslinked HDPE were compared with those of the uncrosslinked HDPE. (C) 1999 Elsevier Science Ltd. All rights reserved.