Renewable Polyesters | Scott Bader

The global composites industry underpins some of the most important sectors driving the transition to a low-carbon economy. From lightweight automotive components to wind turbine blades, composites materials deliver strength, durability and performance required for modern transport and energy infrastructure. However, their value comes with a fundamental limitation, most composite resins are neither recyclable nor repairable.

Traditional thermoset systems, specifically epoxy-based resins are engineered for performance. Once cured, they form a rigid, crosslinked network that cannot be easily reshaped, repaired or broken down. As a result, end of life composite components often end up in landfill or are incinerated, creating both environmental and economic inefficiencies.

Advances in materials science are now opening a new pathway. By rethinking resin chemistry at a molecular level, it is possible to design materials that maintain high performance while enabling circularity. This case study explores how the University of Oxford and Scott Bader are collaborating to develop renewable polyesters that bring recyclability and repairability into the composites value chain.

The Challenge: A Non-Circular Composites Industry

Despite their widespread use, composite materials present a significant sustainability challenge. The globally composites market reached approximately $94 billion in 2022, reflecting its importance across industries such as construction, aerospace, marine and renewable energy. Yet, the majority of these materials rely on thermoset resin systems which are inherently non-circular.

This leads to several critical issues:

Limited recyclability = recovery of reinforcing fibres, such as carbon fibre is complex and often inefficient.

Poor repairability = damaged components frequently require full replacement rather than repair.

End-of life waste = large composite structures including wind turbine blades contribute to growing landfill volumes.

Addressing this challenge requires a fundamental shift in resin chemistry and design.

The Collaboration: Science Meets Industrial Application

To tackle this issue, a collaborative project was established between the University of Oxford and Scott Bader, bringing together academic innovation and industrial expertise.

The research team at Oxford, led by Dr Mati Concilio, focused on advancing polymer chemistry to enable new material functionalities. At the same time, Scott Bader’s R&D specialists, including Dr Steven Brown, contributed deep understanding of resin manufacturing, processing requirements and commercial constraints.

From the outset, the collaboration was designed to ensure real-world applicability. Key considerations included:

• Feedstock selection: Prioritising commercially available, renewable raw materials with acceptable safety and toxicity profiles.

• Process compatibility: Ensuring new resins could be integrated into existing manufacturing equipment and workflows.

• Material performance: Maintaining the mechanical properties required for demanding composite applications.

The shared objective was to develop renewable polyester resins that deliver high performance while enabling recyclability and repair—without disrupting established industrial processes.

Innovation in Action: What We Achieved

The collaboration resulted in the successful development of a series of renewable polyester resins derived from commercially available feedstocks. More importantly, these materials were designed without the need for complex purification steps, supporting both scalability and cost-efficiency.

Key Achievements:

1. Renewable Feedstock Integration – the team developed polyester resin matrices using renewable raw materials that are readily available at commercial scale with no purification required. This helps to reduce reliance on fossil-based inputs while supporting more sustainable supply chains.

2. Industrial Scale Processing Compatibility – The resins were engineered to exhibit viscosities for existing manufacturing processes. This ensures that they can be adopted without significant changes to current equipment or production methods.

3. Competitive Mechanical Performance – Testing demonstrated that the developed resins delivered mechanical properties comparable to conventional thermosets. Validating suitability for demanding applications.

4. Dynamic Chemistry for Circularity – Combining the polyester network with innovative chemistry enables:

• Low energy recycling: Materials can be reprocessed under controlled conditions without excessive input.

• Repairability: Damaged composite components can be easily repaired, extending product lifespan.

• Re-manufacturing potential: Materials can be reformed into new products, supporting circular use models.

Why It Matters

This collaboration demonstrates how close alignment between academia and industry can accelerate sustainable innovation. By integrating theoretical research with real-world manufacturing insight, the project was instrumental in securing additional support through EPSRC Impact Acceleration Account for follow on research to widen applications and assess manufacturing feasibility.

For Scott Bader, involvement from the early stages ensured that material design was guided by practical considerations such as safety, scalability and processing constraints. This approach significantly increases the likelihood of successful market adoption.

At the same time, the partnership provided the University of Oxford with access to industrial expertise, facilities, and application testing, enabling research outcomes to move beyond proof-of-concept.

As sustainability becomes a defining priority across sectors, this model of collaboration offers a clear pathway forward. Additionally, the partnership has contributed to broader knowledge sharing within the industry. Engagement in research networks and conferences has helped circulate insights into suitable material design and influence future innovation strategies.

Next Steps and Future Impact

While the project demonstrated strong technical feasibility, the next phase will focus on scaling and broader application.

Key areas of development include:

• Scaling production through industrial facilities to validate manufacturing and efficiency and cost effectiveness.

• Expanding formulations to meet the requirements of different composite applications.

• Further performance testing to support adoption of high demand sectors like renewables and transportation.

• Exploring policy and industry alignment to support the transition towards circular materials.

Looking ahead, the implications extended beyond a single material innovation. This work contributes to a wider movement in how composite materials are designed, manufactured and managed at end-of-life. Helping to embed circularity into the chemistry of the material itself, the industry can move closer to achieving sustainable, high-performance solutions at scale.