The Fabrication Of High Strength,High Toughness And Room-Temperature Self-Healing Polymer Complexes Via Multi-Component Complexing Methods

Self-healing materials can autonomously repair the damage inside the materials,which extends their lifetime and enhance the safety of the materials.The intrinsic self-healing materials repair damage through reversible rupture and reconstruction of the dynamic covalent bonds or noncovalent supramolecular interactions to achieve the repeated wound heal ability at the same location.However,intrinsic self-healing polymers,especially the ones with room-temperature self-healing abilities,generally show poor mechanical robustness because the inherent contradictory between the healing efficiency and robustness.In addition,the complicated and multi-step preparation process of intrinsic self-healing polymers is unsuitable for their preparation at a large scale.Therefore,the development of a facile approach to achieve the large-scale fabrication of intrinsic self-healing materials with a combination of excellent mechanical properties and highly efficient healability is highly desirable and a challenging task.In this thesis,by exploring the multi-component complexing method,the mechanically robust,highly stretchable,tough polymer complex materials with room-temperature self-healing functions are developed.1、By exploring the synergistic effects of diverse types of reversible noncovalent interactions,a mechanically robust,highly stretchable,tough ternary polymer complex with room-temperature self-healing function was developed using a simple multi-component complexing method.The strong electrostatic interactions between branched poly（ethylenimine）（bPEI）and poly（acrylic acid）（PAA）can effectively enhance the mechanical robustness of the materials,while the weak hydrogen bonds between PAA and poly（ethylene oxide）（PEO）facilitated the unfolding and sliding of the polymer chains,imparting stretchability.The synergistic effects of both electrostatic and hydrogen-bonding interactions within their networks endowed the materials with superior strength（27.4 MPa）and toughness（110 MJ/m³）.More importantly,the bPEI/PAA/PEO complexes can achieve highly efficient self-healing at room temperature（healing efficiency of 97%）owing to their dynamic characteristics of noncovalent cross-linkages and the excellent chain mobility of the polymers at room temperature.2、In-situ synthesized Prussian blue nanoparticles reinforced polymeric complexes with excellent mechanical properties and high efficient healability were fabricated by one-step complexing PAA-Fe³⁺and PEO-K₄Fe（CN）₆ in solution at pH2.Prussian blue nanoparticles were formed in-situ during the complexing of PAA and PEO and can uniformly dispersed within PAA-PEO complexes,because of the coordination interactions between Fe³⁺and the carboxyl group of PAA.The as-prepared PAA/PEO/PB complexes exhibited the highest reported tensile strength and toughness（24.9 MPa,117.7 MJ/m³ respectively）and excellent stretchability（910%）thanks to the well-dispersed PB nanofillers.At the same time,the hydrogen bondings between PAA and PEO,which can be reversibly ruptured and reconstructed imparted the materials with highly efficient self-healing property at room temperature,with the healing efficiency as high as 98%.