Rapid Fabrication of Malleable Fiber Reinforced Composites with Vitrimer Powder

We present a rapid fabrication method for fiber-reinforced polymer composites based on heat pressing woven carbon fibers and vitrimer powder. Vitrimer consists of a covalently cross-linked network endowed with dynamic covalent bonds, which can be thermally activated to undergo bond exchange reactions, thus enabling the rearrangement of network topology without impairing its integrity. These bond exchange reactions lead to bulk stress relaxation and interface healing at the macroscopic scale, thereby allowing the vitrimer powder to fuse into a matrix embedded with the carbon fibers through a heat press process. We demonstrate for the first time that vitrimer composite samples can be fabricated within a few minutes (as short as 1 min) under different temperatures and pressures, which is significantly shorter than the time required for typical liquid-state manufacturing methods. Additionally, the malleability of the vitrimer matrix allows the composite to be reprocessed through thermoforming, which can greatly expand the manufacturing capability of fiber-reinforced composites. The fabrication method demonstrated in this paper has the potential to enable high volume manufacturing of fiber-reinforced composites in industrial sectors such as the automotive industry.