基于非共价键制备高韧性可修复聚合物复合材料

Interfaces between nacreous tablets are crucial to the outstanding mechanical properties of nacre in natural shells and inspired by the “brick-and-mortar” structure and remarkable mechanical performance of nacre. Excellent research has been conducted to probe the effect of interfaces on strength and toughness of nacre, providing critical guidelines for the design of human-made laminated composites. Herein, a class of graphene oxide (GO) based artificial nacre composite material with self-healing capacity due to non-covalent bonding interactions was fabricated by functionalization of GO with ellagic acid through π-π stacking followed by evaporation-induced self assembling process between ellagic acid modified graphene oxide(EGO) and polyurethane(PU). The artificial nacre displays a strict “brick-and-mortar” structure, with EGO nanosheets as the brick and PU as the mortar. The structure of EGO was characterized by infrared spectroscopy, potential analyzer and X-ray diffraction, and the mechanical properties of PU-EGO were tested by universal testing machine. The results show that ellagic acid (ELA) is successfully adsorbed on GO surface, and when the mass ratio of PU to EGO is 3∶1, the tensile strength and toughness of the material reach 111.2 MPa and 81.5 MJ/m3, respectively (9.6 times and 1.8 times higher than that of PU), attributing to the interlayer slip of GO by breaking and recombing the π-π bond dynamically through which the energy can dissipate when PU-EGO is subjected to tensile stress. In addition, owning to the existence of non-covalent bonds, the resulting polymer composites display good recyclability. This work provides a pathway for the development of artificial nacre with self-healing capacity and recyclability. © 2023 The Author(s).

Preparation of High Toughness Polymer Composites with Self-Healing Capacity via Non-Covalent Bonding;