A New Approach for Monte Carlo Simulation of RAFT Polymerization

In this work, based on experimental observations and exact theoretical predictions, the kinetic scheme of RAFT polymerization is extended to a wider range of reactions such as irreversible intermediate radical terminations and reversible transfer reactions. The reactions which have been labeled as kinetic scheme are the more probable existing reactions as the theoretical point of view. The detailed kinetic scheme is applied to three kinds of RAFT polymerization system by utilizing the Monte Carlo simulation Method. To do this, a new approach of simulation method was used. In this approach, a multi-reaction step was used in each time step. Unknown kinetic rate constants have obtained by curve fitting of the simulation results and theoretical data, applying the least square method; or estimated by considering theoretical facts and experimental findings. The origin of the rate retardation and induction period has been understood by studying the main and pre-equilibrium stages of dithiobenzoate-mediated RAFT homo polymerization. A copolymerization system in the presence of RAFT agent has also been examined to confirm the capability of introduced simulation method in different monomer/RAFT agent systems. The simulation results were in excellent agreement with experimental data, which proves the validity and applicability of the Monte Carlo algorithm.