|Fundamental Studies and Recent Advances in Anionic Polymerization
4. Precise Synthesis of Macromolecules with Designed Architectures
by Means of Living Anionic Polymerization
Polymeric and Organic Materials Department, Graduate School of Science and Engineering, Tokyo Institute of Technology H-127, Meguro-ku, Tokyo, Japan
Nippon Gomu Kyokaishi,(2007),80(3),100-106 General Review in Japanese
Recent advances in precise synthesis of macromolecules with specially designed architectures will be reviewed in this paper. Such designed macromolecules include graft copolymers, comb-like polymers, cyclic polymers, regular and asymmetric star-branched polymers, and a variety of hyperbranched polymers with complexed structures as well as block copolymers and chain-end-functionalized polymers synthesized by living (anionic) polymerization. Their architectures are well defined in branching, position, and shape and chain structures are precisely controlled in molecular weights and molecular weight distributions. Recently, new macromolecules with more complex branched architectures have been further synthesized along with rapid progress of living anionic polymerization and new development of living polymerization systems with different mechanisms. These are star-branched polymers with many arms and multi-components, highly dense comb-like polymers having one polymer segment in each unit, star-linear block polymers, comb-like graft and star polymers, dendritic hyperbranched polymers. A particular example is a seventh-generation well-defined dendrimer-like star-branched polymer having a M of 2 000 000 and comprised of 508 polymer segments and 512 end-functionalities. They are characteristic and quite different from linear polymers in physical property and behavior in solution, melt, and solid state. Furthermore, their different segments are segregated and self-organized at molecular level to form novel nano-scale supra-structures and molecular assemblies.
Living Anionic Polymerization, Block Copolymer, End-functionalized Polymer, Graft Copolymer, Comb-like Polymer, Star-branched Polymer, Dendrimer-like Star-branched Polymer, Hyperbranched Polymer