Simultaneously optimized healing efficiency and mechanical strength in polymer composites reinforced by ultrahigh loading fillers based on interfacial energy and dynamic disulfide bonds

In general, ultrahigh loading fillers can increase the hardness and hinder the interfacial healing progress in polymer composites. Therefore, the healing ability and mechanical strength of polymer composites with ultrahigh filler loading are contradictory properties and are difficult to optimize simultaneously. Herein, self-healing hard polymer composites consisting of 72.4 vol% fillers and self-healing thermoplastic elastomers based on surface energy and disulfide bonds were fabricated. The results showed that in the case that of ultrahigh filler loading, polymer composites not only obtained a high mechanical strength of ∼3.21 MPa and a high self-healing efficiency of ∼92.8%, but also possessed the strong reshape ability. Besides, a physical model was used to describe the self-healing mechanism. The adhesion effectively closed cracks and the surface energy driven the movement of polymer chains as well as disulfide bonds reconstructed new polymer chains at the interfaces, resulting in recovering heal mechanical property.