Evaluation of Thermal Endurance Characteristics of Expanded Polystyrene Foams by Dynamic Compression Modulus

Abstract

For evaluation of thermal endurance in foamed plastics, temperature and time characteristics of compression dynamic modulus of four expanded polystyrene foams were investigated by the dynamic viscoelastic measurements in compression mode. Log t which dynamic modulus 10 or 20% fall as compared with the start time of measurement, has been found to relate linearly with the reciprocal of the absolute temperature from the time characteristics of dynamic modulus in foams before destruction of cell. Thermal endurance temperature that is a measure to evaluate thermal endurance is not suitable for being given by the temperature characteristics of the dynamic modulus, and is suitable for being given by the temperature for setting up durable time from the relations between log t and the reciprocal of the absolute temperature.