Recyclable wind turbine blades - in-situ polymerising thermoplastics (LV_Wind)

Climate change is a topic that is high on the policy agenda and attracts substantial media and public interest. Renewable energies like wind are an important part of decarbonising our economy and slowing climate change. Wind turbine blades are made from a combination of reinforced fibres (usually glass or carbon fibres) and a polymer matrix. These composites boost the performance of wind turbines, allowing for lighter and longer blades with optimised aerodynamics. But the materials used create challenges for recycling of the blades at end of life, creating a dichotomy where the product uses renewable energy to generate sustainable energy but where the material used in large parts of the product and not recyclable.

Most wind turbine blades are made from thermoset materials (epoxy, polyester, vinyl-ester). However, thermoset composites can only be heated/shaped once (molecular changes mean that they are "cured") meaning they are difficult to recycle, resulting in stockpiles of end-of-life WT blades with most ending up in landfill. Sustainability initiatives mean there is a drive towards thermoplastic composites (TPCs) which can be heated/shaped/heated/reshaped and are recyclable.

The LV\_Wind project will demonstrate the performance of a unique & cost-effective thermoplastic material that has the very low processing viscosity of a thermoset matrix (good wettability of fibres, high fibre volume fraction) but with the physical characteristics of a thermoplastic material (recyclable, tough, durable, heat formable). The low viscosity of the polymer at processing temperature enables additives (stealth, fire resistance, multi-functionality) to be delivered in the materials whilst remaining processable and highly recyclable. This will enable high-performance structural products to be manufactured at a suitable rate and cost and where materials can be recovered at the end of the useable life of the wind turbine blade, thereby significantly reducing the amount of blade materials going to landfill.