聚合物可逆互锁网络的设计、制备和应用初探

Reversibly Interlocked Polymer Networks:Design,Preparation and Applications

聚合物复合体系是聚合物材料重要的应用形式,发展能够充分抑制相分离的多组分聚合物复合体系制备新技术有着重要意义.利用动态交联聚合物网络拓扑结构的可逆变换,可以使不同交联聚合物网络间的分子链扩散与混合成为可能,待混合完全后再通过动态可逆共价键闭合来重筑交联网络,最终得到由不同子网络穿插互锁形成的均匀复合交联网络,即聚合物可逆互锁网络,其中的子网络之间没有共价键连接,具有相对的独立性.本文由聚合物可逆互锁网络的设计制备出发,阐述了相关方法的概念、原理和所得材料的结构特点,介绍了基于聚合物可逆互锁网络策略的聚合物材料高性能化与功能化应用实例,内容包括提升和调控力学性能、宽pH水环境中的自修复、增进本征导热率、固态聚合物电解质的优化、多组分聚合物复合体系的可控分离与可控降解以及闭环循环利用等,同时分析了与聚合物互穿网络(IPNs)的区别,最后对这类材料未来可能的发展进行了分析和展望.

Combining different polymers together to obtain multi-component polymer systems is an important and effective method for developing novel polymeric materials and regulating their properties.However,the synergistic effect between different components can hardly play its full role because of the ubiquitous phase separation.To solve this problem,we developed a novel strategy to prepare multi-component polymer systems as follows,in which phase separation can be suppressed.Firstly,two covalent adaptive networks respectively containing orthogonal reversible covalent bonds were synthesized.Next,the two single networks were dissolved in a co-solvent under proper stimulus as a result of the reversible reactions of the included reversible bonds.Accordingly,the solutions with the fragments of the single networks can be well mixed,and the latter were allowed to be reconstructed together through topological rearrangement with the assistance of inter-component secondary interactions during removal of the stimulus and co-solvent.Eventually,co-networks with relative independence,i.e.reversibly interlocked polymer networks,were obtained.Owing to the forced miscibility effect induced by the interlocked structure,even immiscible polymer pairs can be homogeneously interlaced with each other.In this context,there would be more freedom to choose the raw materials,and versatile multi-component polymer systems with high performance and novel functionalities can be developed.The paper introduces the material design and general preparation method of reversibly interlocked polymer networks.Afterwards,the structural features of the interlocked polymer networks,and a few applications of this type of material,including enhancement and regulation of mechanical properties,wide pH range underwater self-healability,improvement of intrinsic thermal conductivity,optimization of polymeric solid phase electrolyte,and controllable isolation/degradation and close-loop recycling of multi-component polymer systems,are discussed.Lastly,the difference between the interlocked networks and interpenetrating polymer networks(IPNs)is analyzed,and the future development in this aspect is prospected.