Ultratough nacre-inspired soybean protein isolate/graphene nanocomposite with flame-retardant, thermal conductivity and recyclable

Abstract

Bioplastics synthesized from soybean protein isolate (SPI) and graphite are promising alternatives but often suffer from their inability of mass production, high-cost, poor mechanical robustness, and even flammability. Herein, the scalable production of nacre-like nanocomposite by using the ball-milling spray method of graphene/SPI materials is demonstrated. The dynamic non-covalent was employed to facilitate the toughening effect of inorganic nano-fillers, while simultaneously utilizing dynamic covalent supramolecular interactions to realize plasticizer reinforcement materials. The dissipation of stress is facilitated through a combination of covalent and non-covalent interactions, thereby enhancing the interface interaction and resulting in materials with superior mechanical properties. The interfacial interaction between the SPI and the nano-reinforce confer exceptional mechanical properties to the bioplastic, achieving an excellent tensile strength 11.01 ± 0.81 MPa and fracture toughness14.52 ± 0.71 MJ/m³, which are 3.4 and 3.5 times, respectively, those of neat SPI. The recycling for highly reinforced nacre-mimetic SPI-based nanocomposites is critically enabled by the dynamic bond and improves the sustainability of bioinspired nanocomposites in cyclic economy. In addition, the SPI composite has exceptional flame retardancy, thermal conductivity, and electromagnetic shielding properties. This study provides new insights into the design of reliable and environmentally friendly biomaterials, which is significant for the development of sustainable development resources.