[en] Non-isocyanate polyurethane foams (NIPUFs) offer a safer, more sustainable alternative to conventional isocyanate-based foams. However, polyhydroxyurethane-type NIPUFs, despite containing covalent adaptable bonds, require harsh reprocessing conditions (160–170 °C for several hours), which limits practical recyclability due to unwanted side reactions. In this work, we introduce cystamine-based dynamic disulfide bonds into self-blown NIPUFs, enabling effective reprocessing at significantly milder conditions (as low as 90 °C) without requiring catalysts or generating any side reactions. Critically, the combination of dynamic disulfide chemistry with NIPU hydroplasticization synergistically enhances bond exchange dynamics, accelerating the foam-to-film transformation under gentle, cost-efficient conditions. This powerful strategy allows the resulting films to be repurposed into high-performance adhesives, showing lap-shear strengths comparable to cyanoacrylate thermoset formulations on stainless steel and glass–steel interfaces, and exceeding those of tested commercial polyurethane thermoset and hot-melt adhesives. Notably, the adhesives also demonstrate strong adhesion, in the same range as benchmarks, on glass and nylon fabrics. Furthermore, the cystamine-containing NIPU adhesives exhibit fast, heat-triggered debonding and are reusable across multiple cycles without notable performance loss. This study presents a versatile and scalable approach to NIPUF design, where the synergistic effect of hydroplasticization and dynamic disulfide bonds enables facile, efficient recycling and repurposing into adhesives—broadening application potential and extending material lifespan.
Research Center/Unit :
CESAM - Complex and Entangled Systems from Atoms to Materials - ULiège [BE] CERM - Center for Education and Research on Macromolecules - ULiège [BE]
Disciplines :
Materials science & engineering Chemistry
Author, co-author :
Lechuga Islas, Victor Daniel ; University of Liège [ULiège] - Complex and Entangled Systems from Atoms to Materials [CESAM] Research Unit - Center for Education and Research on Macromolecules [CERM] - Belgium ; Walloon Excellence [ WEL] Research Institute - Wavre - Belgium
Gillissen, Emeline ; University of Liège [ULiège] - Complex and Entangled Systems from Atoms to Materials [CESAM] Research Unit - Center for Education and Research on Macromolecules [CERM] - Belgium ; Walloon Excellence [ WEL] Research Institute - Wavre - Belgium
Bourguignon, Maxime ; University of Liège [ULiège] - Complex and Entangled Systems from Atoms to Materials [CESAM] Research Unit - Center for Education and Research on Macromolecules [CERM] - Belgium
Grignard, Bruno ; University of Liège [ULiège] - Complex and Entangled Systems from Atoms to Materials [CESAM] Research Unit - Center for Education and Research on Macromolecules [CERM] - Belgium ; University of Liège [ULiège] - FRITCO2T Platform - Belgium
Detrembleur, Christophe ; University of Liège [ULiège] - Complex and Entangled Systems from Atoms to Materials [CESAM] Research Unit - Center for Education and Research on Macromolecules [CERM] - Belgium ; Walloon Excellence [ WEL] Research Institute - Wavre - Belgium
Language :
English
Title :
Foam-to-adhesive recycling of self-blown non-isocyanate polyurethane foams facilitated by integration of disulfide exchangeable bonds and moisture
Publication date :
15 July 2025
Journal title :
Chemical Engineering Journal
ISSN :
1385-8947
eISSN :
1873-3212
Publisher :
Elsevier
Volume :
516
Pages :
163998
Peer reviewed :
Peer Reviewed verified by ORBi
Funders :
F.R.S.-FNRS - Fund for Scientific Research Walloon region
Funding text :
The authors thank the Region Wallonne for funding the Win2Wal project \u201CECOFOAM\u201D (convention 2010130) and the FRFS-WEL-T Advanced Grant project \u201CChemistry\u201D (convention WEL-T-CR-2023 A). Christophe Detrembleur is FNRS Research Director and thanks the \u201CFonds de la Recherche Scientifique (F.R.S.-FNRS, Belgium) for funding. A preprint of this article appeared on ChemRxiv at DOI: 10.26434/chemrxiv-2025-hl2k7. Patent pending (WO2023/104362: Self-blowing isocyanate-free polyurethane foams).
Commentary :
A preprint of this article appeared on ChemRxiv at DOI: 10.26434/ chemrxiv-2025-hl2k7
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