Wind power is great success story, particularly in breezy countries like the UK. However, turbine blades do not last forever and disposing of them has become an environmental concern. Last year I reported how researchers in Germany have come up with a way of separating the balsa wood and fibreglass that makes up the blades. The team then used the wood to create a lightweight yet strong foam that they then used to make a paddle board.

Now, John Dorgan at Michigan State University and colleagues have developed a new composite fibre resin that can be recovered from old turbine blades and made into gummy bear sweets. The new turbine material is made by combining glass fibres with a plant-derived polymer and a synthetic polymer. The team showed that panels made of this thermoplastic resin were strong and durable enough to be used in turbines or in cars.

The panels could then be dissolved in a monomer, allowing the glass fibres to be separated from the resin. The constituents can then be recast to make another panel. Alternatively, the resin can be “upcycled” into higher-value materials. These include food-grade potassium lactate, which Dorgan and colleagues used to make gummy bear sweets.

Dorgan and colleagues presented their research at the Fall Meeting of the American Chemical Society in Chicago.

Flammability concerns

I was surprised to learn that balsa wood is used to make wind turbine blades, but I shouldn’t have been because there seems to be a renaissance in using wood as a building material. However, one thing that is preventing wood from being used in some circumstances is the material’s flammability.

Now, Aravind Dasari and colleagues at at Nanyang Technological University in Singapore have devised a fire-resistant coating for wood. The coating is just 0.075 mm thick and is highly transparent – so the team says that invisible to eye. However, when a flame is applied to coated wood, the coating chars and puffs up to 30 times its original thickness. This char was designed to be extremely heat resistant and it creates an insulating layer that protects the underlying wood from the flames.

The researchers are talking to several companies about commercial applications. Singapore-based Venturer Timberwork, for example, is exploring the use of the coating on their mass engineered timber elements.