Improved healing potential of polymers containing double reversible non-covalent interactions: Linking molecular reversibility and macroscale healing

引入超分子相互作用（例如，氢键，金属-配体相互作用，离子相互作用）是一个很有前途的自愈聚合物概念，因为这些键的高可逆性。在这种情况下，该项目旨在首次在一个聚合物系统中结合两种非共价相互作用，以创造一种自修复材料。为此，将进行三种具有高自愈潜力的聚合物的合成和表征：(i)含有带负电单体的聚合物（具有小摩尔质量的阳离子反离子，离子单体），（ii）含有带正电的金属配合物的聚合物（具有小摩尔质量的阴离子反离子，可逆的金属超分子聚合物），以及（iii）同时含有带正电的金属配合物和阴离子反离子的聚合物网络。除了光照射和氧化还原活性金属配合物的应用外，还将以温度变化为主要触发因素，详细研究这三种材料的性能和自愈特性。自修复性能将根据所使用金属配合物的种类以及聚合物体系中金属配合物和阴离子单体的比例和含量的变化而调整。动力学和愈合程度将确定表面损伤（划痕）和聚合物界面（裂纹）。为了设计材料组合和理解自我修复过程，建模和模拟将是项目的组成部分。

The introduction of supramolecular interactions (e.g., hydrogen bonding, metal-ligand interactions, ionic interactions) is a promising concept for self-healing polymers due to the high reversibility of these bonds. In this context, the project aims at combining, for the first time, two non-covalent interactions within one polymer system to create a self-healing material. For this purpose, the synthesis and characterization of three classes of polymers of expected high potential for self-healing will be performed: (i) of polymers containing negatively charged monomers (with small molar mass cationic counterions, ionomers), (ii) of polymers containing positively charged metal complexes (with small molar mass anionic counterions, reversible metallo-supramolecular polymers), and (iii) of polymer networks containing both the positively charged metal complexes and the anionic counterions. The properties and self-healing features of the three material classes will be investigated in detail using temperature changes as main trigger, besides irradiation by light and the application of redox-active metal complexes. The self-healing properties will be tailored by variation of the kind of the used metal-complex as well as the ratio and content of metal complexes and anionic monomers within the polymer system. The kinetics and degree of healing will be determined for both surface damage (scratches) and polymerpolymer interfaces (cracks). In order to design the material combinations and to understand the selfhealing processes, modelling and simulation will be integral parts of the project.