Kinetic model of the evaporation process of benzylbutyl phthalate from plasticized poly(vinyl chloride)

The kinetic model of the physical process of evaporation of plasticizer from plasticized PVC foils was developed from the results of isothermal thermogravimetric investigation of evaporation of benzyl-butyl phthalate in the temperature range 120–150 °C under nitrogen flow. The kinetic parameters were estimated by integral method of analysis. Mathematical modeling of the kinetic of plasticizers evaporation was performed on the basis of function c=f(T,t) and kinetic equation of evaporation −dc/dt=f(T,c0,c(t)). The developed mathematical model was described by the general kinetic equation −dc/dt=(kr exp(kpT)c0+kqT+kw)c(t). The differential quotients δ(−dc/dt)/δT=f(T,c0,c(t))=f(T,c0,t) and δ(−dc/dt)/δc0=f(T,c(t))=f(T,c0,t) were performed, and mathematical definition of the changes of the evaporation rate constant with the change of temperature and the change of the initial plasticized concentration were discussed.