Abstract
Polyurethane (PU) foams are all around us, from our walls to our beds and our cars. Only 20% of this PU is recycled, primarily into inferior products. Polyurethane is a heteropolymer of a polyol and a diisocyanate, mostly forming networks. It is well-understood that these monomers can be cleaved using various chemical recycling techniques, but only pilot plants using mattresses as feedstock are currently operational. To limit the complexity and avoid the difficulty of end-of-pipe purification, the foams should be sorted prior to recycling. Sorting based on isocyanate type can be done using near-infrared identification, due to limited isocyanates industrially used. However, the polyols used in PU are very diverse, limiting sorting possibilities. To enable sorting based on polyol, I propose to tag the polyols with a spectroscopically detectable tag. The tags proposed in this research are fluorophores. This research will provide a proof-of-concept that fluorescent tags can be attached to polyols and used to identify that polyol in PU foam. This will be done by synthesising functionalised tags, comparing different methods of attachment, followed by investigating the properties, stability and recyclability of foam with tagged polyols. This will provide applicable basic tag structures and an optimised screening method to find more tags that are suitable for PU foam. After implementation, this will lead to higher quality recycled polyols and an increased foam circularity.
Researcher(s)
Research team(s)
Project type(s)