Radical Polymerization of Styrene in the Presence of Nitroxyl Radicals.Experiments and Simulations

摘要

Polymerization of styrene in the presence of a stable radical TEMPO has beensimulated using a Predici simulations package. Based on the experimental data, a kinetic model for the TEMPO-moderated polymerization of styrene has been proposed. It was shown that in order to properly simulate the experimental data, in addition to the reversible cleavage of the TEMPO-polymeric radical adduct, it is necessary to include thermal self-initiation, transfer and irreversible decomposition of intermediate alkoxyamines in the polymerization model. This model, combined with the experimental data and literature values of the rate constants of propagation (kp), termination (kt), transfer (ktrm), and alkoxyamines decomposition (kdecomp), was then employed to estimate kinetic and thermodynamic parameters of the exchange between dormant and active species. The equilibrium constant K was estimated to be around 1.10(exp -10) mol/L, the