Thermoelastic properties of plasticized polyvinylchloride

A thermodynamic study was made of the elongation of polyvinylchloride over the concentration range of a didecylphthalate plasticizer of 0 to 70%. It was shown that the reduction of entropy and enthalpy in elongation depends markedly on the concentration of the plasticizer having maximum values in the region of 7–30% and minimum in the region of 60–70%. Results are interpreted on the basis of structural concepts concerning plasticized PVC and calculations of physical network parameters intermolecular bonds.