Recovery and reuse of carbon fibre and thermoplastic resin from composites for marine application

Abstract : Carbon fibre reinforced composites (CFRC) are finding more and more applications to replace conventional materials in many fields such as recreational boatbuilding. This increasing demand is justified by their excellent mechanical properties at lower densities and their corrosion and fatigue resistance. The current global environmental and economic challenges together with the increasing restrictive legislation are driving the development of new sustainable routes towards better environmental footprint of composites. Recently developed liquid thermoplastic resins could represent good candidates to replace thermoset resins in boats construction. They may offer the possibility to recover raw materials from retired parts. A first proof of concept of recovery and reuse of both reinforcement and matrix from a carbon fibre reinforced acrylic thermoplastic composite by pyrolysis is presented in this work. Reclaimed clean carbon fibre as well as recycled matrix were used to remanufacture semi-recycled and fully recycled good quality composites by resin infusion with around 55% fibre volume fraction. The morphological study at fibre scale resulted in concluding that sizing has been decomposed during depolymerisation process. Mechanical properties were retained after recycling compared to reference material. The changes were less than 3% for the tensile modulus and 4% for tensile strength. The same trend was found by dynamic mechanical analysis, with some clear similarities between virgin and recycled Elium resin. Interlaminar shear analysis highlighted a significantly enhanced interfacial strength compared to reference material.