Recyclable, flame-retardant and smoke-suppressing tannic acid-based carbon-fiber-reinforced plastic

Recent environmental issues have driven the development of bioderived chemicals for new composite materials and recycling methods. This paper presents the use of tannic acid (TA)-based epoxy as a polymeric matrix for fabricating and recycling carbon-fiber-reinforced plastic (CFRP). TA plays a critical role in increasing the adhesion of the interface between a polymeric matrix and carbon fiber (CF), ultimately improving the mechanical properties of the CFRP. In addition, its char forming ability endows the CFRP with flame-retarding and smoke-suppressing properties. TA-based CFRP can be treated with supercritical deionized water (scDW) with no additives, producing carbon spheres from the degradation of the epoxy matrix and clean CFs. Each product can be applied as various materials for different purposes. In this paper, a new paradigm is suggested to fully recycle epoxy-based CFRP composites.