Development of a completely recyclable glass fiber‐reinforced epoxy thermoset composite
Matthieu Lejeail, Hartmut Fischer
Abstract
Abstract Stimulated by the growing demand for more sustainable polymer systems, experiments were performed to develop completely recyclable epoxy‐based thermoset composite materials involving the separation, recovery, and complete reuse of both components of the composite, the resin and the fibers. In this study, a possibility to design such composites by incorporation of reversible chemistry for dedicated repair and recycling is demonstrated. Relying on Diels–Alder (DA) adducts located on the cross‐links between the polymeric chains, uncross‐linking the thermoset via the reverse DA reactions becomes possible. The network breaks up at elevated temperatures in shorter segments, which can be solubilized in solvents like acetic acid, butan‐1‐ol, or toluene. Specific processes for each of these solvents were developed to recover the resin and fibers with virtually unchanged properties. Both components were used in a second manufacturing step to produce recycled composites which display properties comparable with the original composites.