|Multiple Controlled Graft Copolymers
by Transition Metal-Catalyzed Living Radical Polymerization
Department of Applied Chemistry, Graduate School of Engineering, Nagoya University, Chikusa-ku, Nagoya, Japan
Nippon Gomu Kyokaishi,(2008),81(10),424-430 General Review in Japanese
This study is directed to the synthesis of a series of well-defined graft copolymers with the controlled lengths of both the backbone and graft chains by the ruthenium-catalyzed living radical polymerization. The backbone polymer was first synthesized by the ruthenium-catalyzed living radical random copolymerization of methyl methacrylate and 2-(trimethylsilyloxy)ethyl methacrylate followed by the in-situ transformation of the silyloxyl group into the ester with a C-Br bond, which resulted in efficient multifunctional macroinitiators for living radical graft copolymerization. The methodology led to the novel controlled architectural copolymers, AxBAx-type block-graft copolymers, which can function as new building blocks for controlled nanostructures based on microphase separation and is different from that of the conventional ABA triblock copolymers. A series of well-defined AxBAx-type block-graft copolymers consisting of soft middle segments (dodecyl methacrylate) and hard outer graft chains (styrene) were synthesized by the ruthenium-catalyzed block and graft polymerizations to exhibit characteristics of a thermoplastic elastomer.
Living Radical Polymerization, Graft Copolymers, Ruthenium Complex, Thermoplastic Elastomer, Block Copolymers, Nanostructures