Abstract: | The viscoelastic response of plasticized PVC was determined from stress-relaxation data over a wide range of time at different temperatures. The relaxation modulus as a function of time was determined from these data. The relaxation curves were then shifted horizontally to obtain a master curve at a reference temperature. The amount of shift was evaluated using the WLF equation. The coefficients C and C used in the equation for the PVC were determined according to the method of reduced variables. |