Variation of Elastic Moduli and Wave Velocity with Pressure and Temperature in Plastics

Abstract

The variations in velocity of dilatational waves in the pressure range 0 to 15,000 lb./in.² and temperature range 30° to 90°C have been measured for samples of polystyrene, Lucite, and polyethylene. The velocity of rotational waves was also measured for polystyrene and Lucite. In polyethylene no trace of a rotational wave could be identified. The elastic moduli and Poisson's ratio are computed over the experimental range.