Study on influence of the tali chain of macromonomers on the radical chain polymerization

点击翻译按钮获取中文摘要

Macromonomers are composed of a polymerizable end group and a tail chain. In this study, radical chain polymerization of methacrylate as well as vinylbenzyl terminated polystyrene macromonomers was investigated to understand the influence of the tail chain connected to the polymerizable end group. Polymerization rate, Rp, degree of polymerization of the product, DP, and the rate constants for propagation and termination reactions, k_p and k_t, in the polymerization in solution were measured by using GPC and ESR spectrum. The macromonomers with different molecular weights were prepared by the living anionic polymerization technique. It was found that the k_t strongly depended on both the tail chain length and the macromonomer concentration in feed [M], while k_t did not show a clear dependence on the tail chain length and the [M]. Bulk polymerizations in melt state at higher temperature than the glass transition temperature of the tail chain were also carried out, the results of which showed the strong diffusion control effect and the influence of the equilibrium monomer concentration. Furthermore, the molecular properties and the mesomorphic phase formation of the polymerization products, i.e., poly(macromonomer)s, were also investigated to clarify the nature of the multibranched propagating chain and the structure formation in polymerization media.