亚表面引发原子转移自由基聚合制备牢固的嵌入式聚合物刷

Sub-surface initiated atom transfer radical polymerization for robust embedded polymer brushes

本文展示了一种新的材料表面改性方法:原子转移自由基聚合(sSI-ATRP)的亚表面修饰,即通过ATRP反应在聚合物材料界面嵌入聚合物刷,构筑稳定的、厚的聚合物亚表面层.首先,将ATRP引发剂分子通过共价键引入到丙烯酸树脂、聚氨酯、聚酯、环氧树脂等聚合物材料中,然后该基底材料在含有催化剂的单体溶液中引发表面原子转移自由基聚合.表面接枝的亲水聚合物刷使材料的表面变得亲水并发生溶胀,使得单体溶液可以进一步接触到材料内部的引发剂而引发新的ATRP反应,该过程不断重复,最后在基材表面上形成几十微米厚的聚合物刷改性的亚表面层.与传统的表面接枝的聚合物刷相比,这种嵌入式的聚合物刷赋予材料表面改性层更好的机械性能,可承受高载摩擦和更好的抗海生物附着特性,且在改性亚表面层破坏后,不需要引发剂修饰组装而再次重复引发聚合改性.

In this article, we demonstrate a new methodology-sub-surface initiated atom transfer radical polymerization(sSI-ATRP)–to construct thick and robust sub-surface polymer brushes layer. In this methodology, the haloid initiator moieties are covalently coupled with acrylic polymers, polyurethane, epoxy resin and other materials,and triggered atomic transfer radical polymerization in hydrophilic monomer solutions. In this process, surface-grafted hydrophilic polymer brushes make the surface of the materials hydrophilic and swell so that the monomer solution can contact the initiator embedded in the materails to trigger new ATRP reactions. This process is repeated and a thick polymer brush modified sub-surface layer can form on the substrate finally. In comparison to the conventional surface floated polymer brushes, the embedded polymer brushes give materails better mechanical property that can bear high load in frictional sliding and better chemical stability with longer duration antifouling activity in ocean field.