Stochastic Simulation of Controlled Radical Polymerization of Den-dritic Hyperbranched Polymers

Abstract

We have recently developed a novel one-step method for the synthesis of hyperbranched polymers (HBPs) with a controlled molecular weight and branch structure and narrow dispersities (Đ = 1.5~2) based on the reversible deactivation radical polymerization (RDRP) using a branch-inducing monomer, evolmer. While the observed Đs of the resulting HBPs were sig-nificantly smaller than those of HBPs synthesized by radical polymerization (Đ > 4), they were still higher than those usually observed for linear polymers (Đ < 1.5) synthesized by RDRP. The origin of the higher dispersity of this method was exam-ined by stochastic simulation of the formation process of the HBPs consisting of the elementary steps involving RDRP. The simulation program successfully reproduced the Đs during the polymerization process. Furthermore, the simulation sug-gested that the higher Đs are due to the distribution of the number of branches instead of undesired side reactions, such as the termination reaction. In addition, the majority of HBPs have structures close to the ideal one, and the HBPs have a well-controlled branch structure. In addition, the simulation also suggested the slight dependence of branch density on molecular weight, which was experimentally confirmed by synthesizing HBPs with an evolmer having phenyl group.