The Thermodynamics of a Strained Elastomer. II. Compressibility

Abstract

Adiabatic compressibility coefficients were measured on a series of cured polymers of commercial types under pressures up to 5000 lb./in.2. In most cases, the second order as well as the first order coefficient could be determined from the data. The linear isothermal compressibility also was calculated from the measured linear adiabatic coefficient. Preliminary measurements of the thermal expansion of a stretched Hevea gum stock show that there is a slight decrease in expansion at the 200 percent elongation, presumably due to partial crystallization.