EOLIAN has reached a strategic milestone in sustainable composites by successfully infusing novel bio-based vitrimer resins with basalt fibre reinforcement to produce high-quality composite laminates compatible with current wind turbine blade manufacturing methods. This achievement validates the use of vitrimer matrices, engineered for repairability, reprocessability and recyclability, in a liquid infusion process traditionally used for large-scale composite structures, and marks a pivotal step toward the development of a 12-metre demonstration blade that could significantly enhance material circularity and end-of-life strategies for wind energy rotor blades.

The fibre reinforced composites currently used to manufacture wind turbine blades are not easy to recycle, explains EOLIAN project coordinator Marco Monti of Proplast.

In recent years, vitrimers have emerged as a potential breakthrough solution to this problem. The manufacture of bio-based vitrimer composites using the infusion process employed by blade manufacturers is extremely challenging and this achievement is an important first step towards our project s goal the production of a 12 m long vitrimer composite demonstration blade.

Vitrimer Composites A More Sustainable Alternative

Driven by the need to reduce environmental impact, wind turbine blade manufacturers are actively seeking more sustainable, circular materials to substitute the glass fibre reinforced thermoset composites currently used in blade production. EOLIAN is addressing this demand by developing a new generation of composite materials combining a bio-based vitrimer matrix with natural basalt fibre reinforcement. The unique properties of vitrimers including repairability, reprocessability, and recyclability will contribute to enhanced sustainability throughout the blade s life cycle. Vitrimers also pave the way to different end-of-life strategies, from reuse through thermoforming, to chemical recycling enabling separation of fibre from matrix.

In order to realise these potential benefits EOLIAN must however develop vitrimer formulations that satisfy the wind industry s stringent standards for performance, manufacturing, and cost. A strategy for transitioning these innovative materials from laboratory to industrial application is also essential.

Promising Progress

EOLIAN partner Tekniker is leading the synthesis of imine-based vitrimers using sustainable building blocks such as vanillin and epoxidised vegetable oils, which are available at industrial scale at reasonable price. As well as being compatible with the infusion process, the vitrimers must possess the thermo-mechanical properties required by the wind energy sector while maintaining their vitrimeric behaviour. The vitrimer matrices should also be reprocessable, repairable, and easily recyclable at soft conditions (low temperature and pressure, without the use of sophisticated equipment).

EOLIAN has successfully developed vitrimers with a bio-based content of 60% which demonstrate key vitrimer properties such as reprocessability and repairability. Proplast and the Polymer Engineering Lab (PolyEngLab) at Politecnico di Milano have carried out infusion trials using the most promising formulations. The high viscosity and short pot-life of vitrimers typically make infusion challenging. However, in recent tests the EOLIAN team has successfully manufactured high-quality basalt fibre reinforced laminates at moderate temperatures (room temperature up to 80 C). The composites exhibit optimised fibre volume fraction and low void content.

Research and testing are continuing to refine the vitrimer formulations and achieve the optimal balance between bio-based content, processability, and final performance to ensure their successful implementation in blade manufacturing.

Cristina Monteserin, Researcher, Tekniker: The work being carried out within EOLIAN represents a significant step forward in the development of high-performance, eco-friendly vitrimer composites. With growing global emphasis on green energy and circular economy principles, these innovations could play a transformative role in the future of sustainable materials for the wind energy sector and beyond.

Marco L. Longana, Associate Professor, Politecnico di Milano: By participating in EOLIAN, PolyEngLab is pushing the boundaries of sustainable polymer composites, ensuring that future wind turbine blades are more durable, repairable, and recyclable. This project strengthens our position as a leader in advanced materials research while supporting EU sustainability goals.