Investigation of Variation in the Rates of Reactions and Concentration of Reactants in Free Radical Polymerization Using Stochastic Methods

In the present study, the variation of rates of initiation, propagation, and termination reactions as well as the variation of reactants (including monomer and initiator) were investigated by using stochastic methods. The concentration of free radicals was also depicted as a function of monomer conversion. The results show that the concentration of monomer decreases linearly with conversion while the concentration of free radicals is an exponential function of reaction time. In fact, quasi-steady state assumption is not valid for batch systems in the absence of gel effect and the concentration of free radicals changes during the reaction. Considering the fact that the concentration of initiator exponentially falls during the reaction, the concentration of free radical also drops as the polymerization proceeds. Finally, the rate of initiator decomposition declines exponentially while propagation rate drops linearly.