Grafenberg, Germany – Rampf has developed a way to make customised polymer aerogels that upcycles waste polyurethane. It takes mixed PU-based production scraps, and turns them into ultralight eco-friendly materials that can be used in applications such as thermal insulation, lightweight fillers, rheology additives and oil binding agents.
First, a glycolysis process is carried out on unsorted PU scraps, leading to a recycled polyol. This is used to synthesise a PU-based gel. The wet gel is then subjected to supercritical drying, resulting in an aerogel.
Initial attempts were made using scraps from Rampf Tooling Solutions’ Raku Tool modelling boards. They subsequently found that the approach can equally well be applied to other forms of polymer, and might prove to be a practical way of treating complex plastic waste.
Gerd-Sebastian Beyerlein, director of new business development at Rampf and technology lead on the project, said that they found the technical properties of the aerogels are highly dependent on physical microstructure, but the purity of the feedstock is less important.
“The aerogels we synthesised from different batches of mixed production scraps possess a well-defined and adjustable mesoporous microstructure, as well as very low thermal conductivity in the range of comparable high-performance insulation materials,” he said.
“The transfer of this newly developed approach to other polymers as well as bio-based precursors could significantly accelerate the development of holistic circular economies. We are convinced that it has the potential to pave the way for a new generation of sustainable value-added polymers and can effectively contribute to the reduction of plastics waste in our ecosystem.”
Rampf Group CEO Michael Rampf added that the project shows the company is a pioneer of chemical recycling. “Whilst our company Rampf Eco Solutions has been developing and optimising the processing of sorted production scraps for more than two decades, we have now found a revolutionary solution that could signal the end of unsorted residues being incinerated or thrown in landfills,” he said.
Further details about the technology can be found in a recent article in the Journal of Sol-Gel Science and Technology. The paper is available on open access.