Liège, Belgium – Researchers at the University of Liège have developed a non-isocyanate foaming process, which they believe to be compatible with existing industrial foaming infrastructures. The resulting non-isocyonate polyurethane (NIPU) foam is said to be recyclable.
The team at the University’s Centre for Research on Macromolecules (CERM) have used CO2 created from a reaction of water with cyclic carbonate compounds, and a catalyst, to blow the foam matrix.
Lead author of the study, Maxime Bourguignon said: ‘We have succeeded in mimicking the foaming technology of conventional polyurethanes by replacing the toxic isocyanates with easily accessible cyclic carbonate compounds. Our technology uses water and a catalyst to convert part of the cyclic carbonates into a gas – CO2 – that blows the matrix, while the other part simultaneously reacts with amines to cure the foam. The result is a solid material with a low density and regular pores. Our cyclic carbonates are easily obtained by chemical transformation of CO2 and thus fulfil a dual role, generating the blowing agent and forming the polymer matrix, the polyurethane.’
Christophe Detrembleur, research director at CERM said: ‘Replacing this old chemistry with a more environmentally and health-friendly one, while valorising an emblematic waste – CO2 – as a raw material, has become a priority for the production of more ecological and recyclable cellular materials.’
The study has been published in the peer-reviewed journal Angewandte Chemie International Edition.
