Sustainable composites based on vitrimer matrices PhD

Thermosetting polymers are currently the matrix of choice, due to easiness of processing, their high environmental resistance and good mechanical properties; however, their irreversibility of processing makes recycling of the produced composite a major challenge. The alternative solution of thermoplastic matrices, although an advancement in terms of sustainability, generates significant issues with respect to energy consumption, limited processability and lower environmental resistance.

Vitrimers have been proposed as an intermediate solution combining the processability of thermosets with the reversibility of thermoplastics.

Work in the Cranfield Composites and Advanced Materials Centre has recently resulted in the formulation and development of vitrimers that match the processability and performance of advanced thermosetting matrices (epoxies and benzoxazines) whilst also showing effective self-healing and recyclability. The new matrices, which are formulated using a solventless one-pot route, have demonstrated a high level of property recovery upon re-manufacturing.

This project aims to develop fully recyclable composites by transferring these developments to carbon fibre reinforced materials. The project will optimise the matrix formulation for achieving the best combination of processability and composite property recovery upon re-manufacture. The formulation and manufacturing activities, will be accompanied by extensive characterisation of mechanical performance of the composites, including quasistatic properties, impact response, and environmental resistance as well assessment of the evolution of properties following numerous cycles of re-manufacturing.

Successful completion of this research will provide a composite material system that combines ease of processing, advanced mechanical and thermal properties and the capability to self-heal and be recycled. This will correspond to a significant leap in sustainability of composites that will have the potential to alter industrial practice leading to recyclable advanced composites.

The work will make full use of facilities within the Composites and Advanced Materials Centre including a thermal and thermo-mechanical analysis suite, pilot scale composites manufacturing equipment as well as the Mechanical Testing Lab in the School of Aerospace, Transport and Manufacturing.