Performance Self-Blown Non-Isocyanate Polyurethane Foams
10 affiliations
- 1POLYMAT and Department of Polymers and Advanced Materials: Physics, Chemistry and Technology, Faculty of Chemistry
- 2University of the Basque Country UPV/EHU
- 3Instituto de Química, Universidade Estadual de Campinas (UNICAMP, Rua Monteiro Lobato 270, Campinas, São Paulo, Brazil, 13083-862
- 4Laboratory of Polymeric and Composite Materials, Center of Innovation and Research in Materials and Polymers (CIRMAP, University of Mons, Place du Parc 23, Mons, Belgium, 7000
- 5State Key Laboratory of Advanced Polymer Materials, College of Chemistry
- 6Sichuan University
- 7Chemistry Department, University of Liège, 13 allée de la Chimie, Liège, Belgium, 4000
- 8Institute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovského nám. 2, Prague, Czech Republic, 162 00
- 9Institutional CCU Technology Platform, University of Liège, 13 allée de la Chimie, Liège, Belgium, 4000
- 10WEL Research institute, avenue Pasteur 6, Wavre, Belgium, 1300
Abstract
Rigid foams earn their place in structural applications through a specific balance of stiffness and density. Reproducing that balance without isocyanates has proven far harder than replacing the chemistry itself. Water-blown polyhydroxyurethane (PHU) foams are the most credible isocyanate-free alternatives to conventional polyurethanes, but toxic base catalysts and weak mechanical properties have stalled their adoption. Brønsted acid catalysis, long dismissed on the expectation that amine protonation suppresses urethane formation, proves effective instead: a dynamic equilibrium of transient protonation and thermal amine regeneration widens the rheological window for water-driven CO2 release while carrying the network to full conversion. Acidic conditions additionally activate vinyl ethers, converting the pendant and vicinal hydroxyls responsible for moisture plasticization into acetal crosslinks. The resulting poly(hydroxyurethane)–polyacetal (PHU–PAC) foams show a sixteenfold (16x) higher rubbery modulus, a fourfold higher compressive modulus (4 → 18 MPa), and halved water uptake relative to the PHU benchmark. Normalized peak heat release rate falls nearly eightfold below that of a commercial PU foam, and on an Ashby plot of specific strength versus stiffness, PHU–PAC approaches HDPE and PVC. Addressing catalyst tractability, moisture uptake, and mechanical performance in one formulation, acid-catalyzed PHU–PAC reframes non-isocyanate foams as tunable structural materials and positions catalyst design as a lever for the next generation of sustainable cellular materials.
Related
- Self-Blowing Non-Isocyanate Polyurethane Foams Based on Hydrolysable Tannins
- Overcoming the Density Limitation of Polyhydroxyurethane Self-Blown Foams through Sol–Gel Chemistry
- Hydrolysable Chestnut Tannin Extract Chemical Complexity in Its Reactions for Non-Isocyanate Polyurethanes (NIPU) Foams
- "Preparation of cast polyurethane foams by physico-chemical co-foaming process and their properties"
- Microwave-Assisted Depolymerization of Polyurethane and Polyisocyanurate Foams with Diethylene Glycol and Epoxidized Tall Oil-Based Polyol
BibTeX
@misc{perli2026performance,
title = {{Performance Self-Blown Non-Isocyanate Polyurethane Foams}},
author = {Gabriel Perli and Guillem Seychal and Bruno A. Piscelli and Yi Wang and Maliheh Razavi-Esfali and Lucas Polo Fonseca and Hynek Beneš and Xabier Lopez de Pariza and Jon Ayestaran and Rodrigo A. Cormanich and Li Chen and Bruno Grignard and Christophe Detrembleur and Nora Aranburu and Jean-Marie Raquez and Haritz Sardon},
howpublished = {ChemRxiv},
year = {2026},
month = sep,
doi = {10.26434/chemrxiv.15009148/v1},
url = {https://chemrxiv.org/doi/full/10.26434/chemrxiv.15009148/v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - Performance Self-Blown Non-Isocyanate Polyurethane Foams
AU - Gabriel Perli
AU - Guillem Seychal
AU - Bruno A. Piscelli
AU - Yi Wang
AU - Maliheh Razavi-Esfali
AU - Lucas Polo Fonseca
AU - Hynek Beneš
AU - Xabier Lopez de Pariza
AU - Jon Ayestaran
AU - Rodrigo A. Cormanich
AU - Li Chen
AU - Bruno Grignard
AU - Christophe Detrembleur
AU - Nora Aranburu
AU - Jean-Marie Raquez
AU - Haritz Sardon
PY - 2026
DA - 2026/09/21
PB - ChemRxiv
DO - 10.26434/chemrxiv.15009148/v1
UR - https://chemrxiv.org/doi/full/10.26434/chemrxiv.15009148/v1
AB - Rigid foams earn their place in structural applications through a specific balance of stiffness and density. Reproducing that balance without isocyanates has proven far harder than replacing the chemistry itself. Water-blown polyhydroxyurethane (PHU) foams are the most credible isocyanate-free alternatives to conventional polyurethanes, but toxic base catalysts and weak mechanical properties have stalled their adoption. Brønsted acid catalysis, long dismissed on the expectation that amine protonation suppresses urethane formation, proves effective instead: a dynamic equilibrium of transient protonation and thermal amine regeneration widens the rheological window for water-driven CO2 release while carrying the network to full conversion. Acidic conditions additionally activate vinyl ethers, converting the pendant and vicinal hydroxyls responsible for moisture plasticization into acetal crosslinks. The resulting poly(hydroxyurethane)–polyacetal (PHU–PAC) foams show a sixteenfold (16x) higher rubbery modulus, a fourfold higher compressive modulus (4 → 18 MPa), and halved water uptake relative to the PHU benchmark. Normalized peak heat release rate falls nearly eightfold below that of a commercial PU foam, and on an Ashby plot of specific strength versus stiffness, PHU–PAC approaches HDPE and PVC. Addressing catalyst tractability, moisture uptake, and mechanical performance in one formulation, acid-catalyzed PHU–PAC reframes non-isocyanate foams as tunable structural materials and positions catalyst design as a lever for the next generation of sustainable cellular materials.
ER -