REPOXYBLE will make extensive use of Advanced Manufacturing Technologies to realize bio-based, lightweight, highly performant, and sustainable, multifunctional composites.
New bio-based epoxy-composites will be developed starting from existing competitive market bio-based alternatives mixed with proprietary depolymerizable building blocks (hardeners, resins), that will be used in combination with bio-based fibres (flax) for the automotive application, and carbon fibres for the aeronautics use case. This approach will allow to replace the use of fossil-based building blocks, fibres and additives by bio-based and renewable alternatives, contributing further to the principles of sustainability for thermoset composites. These high bio-based carbon content epoxy binders will be the starting point to implement a Depolymerizable Closed Loop Epoxy (DCLE) system, that will ensure a high efficient valorization of all the composite constituents into high value products.
The DCLE technology consists of a chemical recycling process involving simple solid/liquid and chemical separation techniques that allows to retrieve all the composite components, meaning initial monomers and building blocks of epoxy resin, fibres, additives and reinforcement fillers. It is carried out close to room temperature (RT), at atmospheric pressure and in water-based acidic media by a low energy consuming process, and these advantageous soft conditions prevent the potential damage of the reinforcement fibres and inorganic additives. Therefore, the resulting secondary raw materials of DCLE will be reactive monomers or building blocks ready to be repolymerized into the same or new thermoset compositions. This innovative system takes a step forward and opens the door to a new circular methodology for sustainable supply chains, where the recycling products can substitute new virgin materials in the same manufacturing process itself (closed loop recycling), enhancing the sustainability profile of our final product solutions, with respect to other conventional epoxy-composites currently used in the transport sector.
Moreover, Advanced Manufacturing Technologies will be essential to study and improve the optimization of curing and recycling processes of the composites towards an energy efficient manufacturing approach. The use of Digital Technologies, in particular advanced modelling, will allow to provide precise simulations of the composite curing process, to adopt a data-driven approach for the improvement and implementation of the productive process.
Other relevant dimensions for REPOXYBLE composites concern improved structural and multifunctional aspects, that will be achieved through the lightweighting and the integration of multifunctionalities into the final material, allowing for enhanced properties, as thermal management, electrical conductivity, and structural sensing during manufacturing.
In this regard, a few layers of graphene ink will be deposited on the epoxy-composite as substrate, to realize a graphene-based coating that will provide an efficient thermal management and an improved thermal conductivity of our composite, with respect to current copper-based heat dissipator.
Printing the graphene ink on the surface or embedded into composite structures, will be also the strategy to introduce in the final system percolative sensors that will provide structural health monitoring, with the goal of demonstrate better accuracy and high repeatability than conventional strain gauges.
Additionally, a given amount of graphene oxide (GO) content in our composite will allow the integration of non-metal circuits, obtained by the reduction of GO with laser, with the advantage of low weight and easy recyclability.
In conclusion, the use of Advanced Materials and manufacturing and Micro/Nano-Electronics will ensure novel and enhanced properties, as well as the multifunctionality of the materials, showing improved performance with respect to the other epoxy-materials currently used in the aerospace and automotive sectors.
Our study cases concern the development of prototype of structural parts for transport sector. For the aerospace case study, we will prototype engine and wing panels of a high-speed airplane studied and developed by the DAC, that will prove high operative conditions and weight reduction compared to the titanium as benchmark.
For the automotive case, we will prototype the monocoque of a fuel-cell low-weight car studied and developed by Riversimple. Our solution will demonstrate improved manufacturing lead time and durability and embedded electrical functions, compared to the conventional epoxy, considered as benchmark.