Self-healing and Healable Polymeric Materials Based on Polymer Complexes

When polymer materials are damaged during usage, they will lose their original mechanical strength and function. Polymer materials with healability can have an extended service life, reduce raw material consumption and improve reliability. Endowing polymer materials with self-healing/healable capacity is an important requirement for the development of sustainable society. Polymeric complexes can be produced by directly mixing polymers with complementary interactions or copolymerization/sequential homopolymerization of two kinds of monomers with complementary interactions in bulk solutions. Polymer complexation provides a flexible method for the fabrication of polymer composite materials crosslinked by noncovalent supramolecular interactions or dynamic covalent bonds. Meanwhile, the mechanical properties of the polymeric composite materials derived from polymeric complexes can be conveniently tailored. This paper gives a comprehensive summary of the solution-based polymeric complexation method for the fabrication of self-healing/healable polymer materials developed in our research group. Based on the polymeric complexation method, we have successfully fabricated polymeric hydrogels, elastomers and high-strength polymer composites with excellent healing capacity. We also demonstrate that the contradiction between the satisfactory healability and high mechanical strength of polymer composites can be solved by integrating a high density of reversible supramolecular interactions and in situ-formed rigid polymeric complex nanoparticles in the targeted polymer composites. The polymeric complex nanoparticles can serve as nanofillers and cross-linkers to significantly improve the mechanical strength of the polymer composites. Meanwhile, the reversibility of supramolecular interactions facilitates the mobility of polymer chains and enables highly efficient healing of damaged composites to restore their original mechanical properties. Moreover, we also fabricated self-healing/healable polymer composite materials with functions such as antifogging, proton conduction and sensing. These polymer composite materials can heal mechanical damage as well as restore their original functions. We believe that the polymeric complexation method provides new avenue for the fabrication of self-healing/healable polymer materials with excellent mechanical properties and functions.