The process of loss of plasticizers: dioctyl phthalate, diisononyl phthalate, benzylbutyl phthalate, dioctyl adipate, phosphate plasticizer Reofos, polymeric plasticizer Reoplex and epoxidized soybean oil from plasticized poly(vinyl chloride) folies was studied by the method of isothermal thermogravimetry in the temperature range 120-150 degreesC. The investigated samples contained ca. 10-40 wt.% of plasticizers. The rate constants of the process of loss of plasticizers were calculated and the dependence of the rate constant on temperature and on the initial concentration of plasticizer in plasticized PVC were mathematically defined. The concentration dependence of the rate constant is expressed by parameters k(0) and q. The linear dependence of the function k = f(c(0)) suggests that the process of evaporation from the polymer surface, being slower, governs the process of the loss of plasticizers. The activation energy of the process was calculated from the exponential dependence of the rate constant of evaporation on temperature. Compensation parameters were also calculated as a measure of reaction ability of the system. The role of various parameters (molecular weight, static and dynamic structure of polymer, polarity) on the kinetic parameters of evaporation of plasticizers were discussed.