Thermodynamic analysis of the inequality of the cohesive energy density and internal pressure of polymers

With a simple thermodynamic analysis, we show that polymers do not satisfy the two major criteria that are required for establishing a unique relationship between cohesion energy density (CED) and internal pressure (IP). Since IP can take values independently of CED, we contend that the IP/CED ratio cannot be established a priori, as the ratio depends on the thermodynamic variables (temperature, pressure, etc.) and the system of interest. POLYM. ENG. SCI., 45:798-800, 2005. © 2005 Society of Plastics Engineers
INTRODUCTION The concept of solubility parameter has been frequently used for the prediction of miscibility of binary polymer blends, as the difference in solubility parameters of the blend components is [...]