If Filip Du Prez has his way, thermosets such as epoxies will be almost as recyclable as thermoplastics in a few years’ time. The first step is to gain a better understanding of how cross-linked plastics work at the molecular level. ’We want to spend the next four years building up knowledge about the combinations of parameters that lead to the best possible material.’

Could you cross-link small molecules into a polymer as precisely as nature does with amino acids? And could such ‘precision polymers’ serve as models for more recyclable materials? In 2021, Ghent professor Filip Du Prez received an ERC Advanced Grant to devote five years to this topic. Thanks to precision polymers, he hopes to learn more about the link between the exact structure of polymer chains and their physical and chemical behaviour. The ultimate goal is to develop industrial thermosets, such as epoxy resins and polyurethanes, that are still useful after use.

’In hot areas, wind turbine blades must retain their thermal stability’

This is certainly not the case with the current generation of thermosets, whose production now stands at 65 million tonnes a year, according to Du Prez. It doesn’t get much better than grinding them for use as fillers. Unlike thermoplastics, they do not soften, let alone melt, when heated. Science doesn’t really have an answer to this yet. It’s only now, as the first generation of wind turbines needs to be replaced, that people are starting to realise that they can’t get to grips with the growing pile of discarded fibreglass-reinforced epoxy blades. ‘Every month I receive a query from a company that wants to know more about the applications of reusable resins or wants to collaborate in this area’, says Du Prez.