Modeling of RAFT Polymerization of Polystyrene by Moment equations

In current work, a mechanism based on intermediate radical termination theory is assumed for RAFT polymerization. Moment equations method was used to model this mechanism and the results were compared to experimental data to verify modeling. According to the fitting of modeled dependencies to the experimental data, rate constants of addition ( a k ) and fragmentation ( f k ) are determined 6×106 lit/mol.sec and 5×104 1/sec respectively, which leads to an equilibrium constant value of 1.2 102 a f K=k k = ´ . The effects of changing of RAFT agent concentration onconversion, molecular weight and polydispersity index of the final product were investigated through the modeling.According to the results, the livingness of polymerization increases with raising RAFT agent concentration which leads to linearity of conversion and molecular weight curves and make polydispersity index and molecular weight distribution become lower and narrower namely.

کلیدواژه ها:

Addition-Fragmentation chain transfer polymerization (RAFT) ، intermediate radical termination kineticmodel (IRT) ، modeling ، moment equations ، kinetics