规整纳米结构的精确构筑:接枝共聚物的合成进展

Construction of Well-Defined Nanostructure:Advances in Preparation of Graft Copolymer

众多结构新颖的聚合物中,接枝共聚物具有独特的高密度刷状结构,能够很好地包容具有不同功能的侧链结构,在表面活性剂、抗污表面、生物医学、纳米技术和超分子科学等领域具有广泛的应用前景。接枝共聚物的结构相对复杂,合成较为困难,其中不对称双接枝共聚物的合成是最具挑战的课题之一。如何构建双接枝共聚物的通用合成平台,精确地向主链同一重复单元引入致密的双侧链Janus结构,是接枝共聚物制备的重要难题。本文综述了接枝共聚物,特别是中国科学院上海有机化学研究所黄晓宇课题组在不对称双接枝共聚物合成方面取得的最新进展。

Among macromolecules with complex architectures,graft copolymers represent a special type in which multiple chains are densely attached to a linear backbone.Because of their compact branched structure and persistent cylindrical shape,such polymers have emerged as a unique class of nanostructured polymers in surfactant,stain-resistance,biomedical,nano and supramolecular science.However,there is still few robust methods for efficient synthesis of such polymers due to their inherently challenging synthesis,especially for asymmetric molecular double-brushes bearing different dense side chains attached to the polymeric backbone with Janus-type conformation.Most of the developed synthetic routes for graft copolymer are limited to the need of polymeric functionality transformation,polynorbornene backbones or special cyclic monomers.How to construct a versatile platform for preparing graft copolymers still keeps a challenge for chemists.The aim of this article is to review and highlight the progress of preparation of graft copolymers,especially for asymmetric molecular double-brushes.Recently,Prof.Xiaoyu Huang and co-workers in Shanghai Institute of Organic Chemistry(SIOC),Chinese Academy of Sciences,have given their unique answer and talented way.Atom transfer radical polymerization(ATRP)is a particularly attractive controlled radical polymerization(CRP)process covering broad monomers,meanwhile,Cu-catalyzed azide/alkyne cycloaddition(CuAAC)“click”reaction with their high specificity and nearly quantitative yields have gained a great deal of attention.Huang et al.found that the combination of ATRP and“click”reaction can be used to directly synthesize the asymmetric molecular double-brushes in one pot system,because either ATRP or“click”reaction employ the copper/ligand catalytic system.This work is a breakthrough for preparation of asymmetric molecular double-brushes.