Plasticizer migration from poly(vinyl chloride)

The applicability of well-known empirical equations to the description of the kinetics of dioctyl phthalate migration from PVC was studied. The validity of empirical equations for predicting the plasticizer migration at temperatures below the critical one is limited because of a probable change in the limiting stage of the process. The temperature at which the limiting stage of the process changes is determined by the geometry of the sample and the conditions of its contact with the environment. At room temperature, the limiting stage of dioctyl phthalate migration from PVC films is controlled by the plasticizer volatility through the polymer surface, whereas at increased temperatures, this stage is determined by the dioctyl phthalate diffusion rate in the polymer.