The current trends in the transport sector concern more efficient structures, electric and hydrogen power, and lightweighting as strategies to reduce use of resources and emissions, and the development of new mobility models and smart and autonomous driving technologies.
Advanced materials can play a significant role with respect to these trends, enabling to obtain lightweight, multifunctional materials, responding to recyclable and circular models.
Epoxies are currently used in the transport sector, but show some limits. In fact, the operative mechanical and thermal conditions to which they are subjected can weaken the structure of the material, and even favour the release of toxic fumes and micro-particles in the environment. Moreover, they show low possibility of recyclability and/or re-utilization.
In this context, we have set up our study cases on the development of new bio-based, lightweight, sustainable, and multifunctional epoxy-based composites, to obtain prototypes of structural parts for two different aeronautics and automotive projects.
REPOXYBLE will consieder two surface panels for prototyping purposes, related to the engine gondola and the wing, respectively, of the hypersonic business jet HYPLANE (by the DAC, Aerospace District of Campania, Italy).
Materials used in aeronautics need to respond to extreme flying conditions. Titanium-based materials are ideal for high-temperature applications but quite expensive and difficult to reinforce.
Therefore, referring to titanium as benchmark, REPOXYBLE key drivers in developing bio-based epoxy resins consist in:
- Achieve high operative temperatures
- Weight reduction
REPOXYBLE will prototype the monocoque of a fuel-cell low-weight car powered by hydrogen rather than batteries, emitting water (by Riversimple, UK).
Considering conventional epoxy materials currently used in the automotive sector as benchmark, REPOXYBLE key drivers for the development of bio-based epoxy resins consist in:
- manufacturing lead time
- Embedded electrical functions
- Improved durability including resistance to environmental conditions
Material and process requirements for both study cases within this project will pay attention to performance aspects and to the reduction of costs and environmental impacts along the whole material life-cycle.
The composites will be developed to respond to strict sustainability criteria, enabling closed loop recycling system of all the components in the end-of-life phase via depolymerization of the epoxy resins, and the final recovery of functional monomers, fillers, and additives as secondary raw materials.
Final requirements set for process, circularity and sustainability aspects refer to benchmarks as well, concerning the conventional epoxy production and disposal processes.
Multifunctionality requirements of the REPOXYBLE composites are finally addressed to integrate thermal and electrical conductivity properties, and enable the following functions:
- Improved thermal management, to dissipate surface heat or de-icing
- Self-sensing and structural (e.g. strain) health monitoring to assess the structural health and plan predictive maintenance
- Laser assisted circuits, to integrate the management of electric currents during lightning strike
- Energy efficient manufacturing by integrating curing sensors.
In order to properly manage the complexity of REPOXYBLE composites, the ambition of the project is to follows a multidisciplinary and holistic approach.