Anomalous heat capacity of high-density polyethylene melts at high temperature

摘要

The first measurements of heat capacity of high-density polyethylene have been obtained for melts in the high-temperature region of 180-260°C. A heat-flow twin calorimeter was used. Abrupt transitions are noticed at 212 and 228°C, analogous to transitions seen earlier with rheological and surface tension measurements. Possible explanations for these phenomena are offered.