Rapid Fabrication of Malleable Fiber Reinforced Composites with Vitrimer Powder

Abstract

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.

Carbon Fiber Reinforced Epoxy Vitrimer: Robust Mechanical Performance and Facile Hydrothermal Decomposition in Pure Water

“…Because CFRPs are not easily recyclable due to the irreversible nature of the crosslinked polymers, most of CFRP wastes are landfilled. There have been only a few studies on recyclable CFRP with epoxy vitrimer matrices in the literature, [ 10,11 ] and those CFRP only show tensile strengths less than 100 MPa as the epoxy vitrimers are based on fatty acid cured epoxies. In contrast, the vitrimer matrices based on anhydride cured epoxies are rigid but exhibit poorer recyclability than those based on fatty acid cured epoxies.…”

“…The tensile properties of the CFRP prepared in this work are much higher than the reported CFRPs based on fatty acid cured epoxy vitrimers which exhibit tensile strengths at below 100 MPa. [ 10,11 ] The excellent tensile property is attributed to the rigid anhydride cured epoxy system as matrices and the abundant OH groups of the polymer matrices which built‐up interfacial adhesion with fibers for efficient loading transfer under external loadings. The thermally induced DTER reconstructs the crosslinked network and provides unique shape changing property.…”

The Impact of Vitrimers on the Industry of the Future: Chemistry, Properties and Sustainable Forward-Looking Applications

“…On a different note, Yu et al tried to improve the production protocol of compression moulding for long fibre composites, with the introduction of a vitrimeric powder [104]. The vitrimer particles become cured and sintered, while at the same time reinforced with a carbon fibre mat in one step.…”

“…The vitrimer particles become cured and sintered, while at the same time reinforced with a carbon fibre mat in one step. Since there is no precuring stage for the matrix, the procedure could be completed in only 1 min (1 MPa at 300°C) [104]. The malleability was demonstrated by reshaping the produced sheet into a pinwheel and by subsequently heating up at 200°C for 3 h. Other relevant studies on composites have been covered in the other sections above [27,28,34,35,78].…”

“…Contents up to 10–25 wt% gave rise to the formation of a network structure in the vitrimer, thereby reaching an optimum in tensile strength while also shortening the relaxation time [ 103 ]. As a final note, we mention Pripol ® 1040, a mixture of di- and tri-carboxylic fatty acids used in combination with DGEBA in several studies focusing on vitrimers [ 31 , 52 , 65 , 68 , 104 ].…”