Kinetics of free radical polymerization of methylacrylate initiated by potassium peroxydisulfate and cetylpyridinium chloride system

Kinetics of phase transfer catalyst (PTC) assisted polymerization of Methyl acrylate (MA) initiated by potassium Peroxydisulfate (K2S208) – cetylpyridinium chloride (CPC) system was investigated in ethyl acetate/water system at 60ºC under N2 atmosphere and unstirred condition. The effect of varying the concentrations of MA, K2S208, CPC, H+, and ionic strength on Rp were studied. From the study, reaction orders with respect to MA, K2S208 and CPC were found to be 1.5, 0.5 and 1. Thermodynamic parameters such as overall activation energy (Ea), entropy of activation (∆S#), enthalpy of activation (∆H#) and free energy of activation (∆G#) were calculated by conducting the reaction at different temperatures in the range 50-60ºC. Rate of the reaction was found to be unaffected by a change in the acid strength and ionic strength of the reaction medium. To account for the experimental observations, the most probable mechanism has been proposed and the rate expression was derived from it.