Polyol and polyurethane foam from cellulose hydrolysate

BACKGROUND At present the majority of polyurethanes, including polyurethane foams (PUF), are obtained from petrochemical substrates. However, green chemistry policy worldwide and restricted crude oil resources are driving the use of biological substrates to make polyurethanes. Widely available cellulose seems to meet the expectation of a polyol substrate for use in synthesizing polyurethane foams provided that it is converted first into liquid resin with free hydroxyl groups. RESULTS Cellulose hydrolysate was functionalized with glycidol and ethylene carbonate to obtain polyol. The product was characterized by infrared and proton nuclear magnetic resonance spectroscopy and matrix-assisted laser desorption ionization-time-of-flight spectrometry. The polyol then was used to obtain rigid polyurethane foam. The foam was characterized by physicochemical methods to determine apparent density, water uptake and polymerization shrinkage. CONCLUSIONS New polyol was obtained from cellulose hydrolysate by reaction with glycidol and ethylene carbonate in the presence of potassium carbonate as catalyst without solvent. This polyol contains hydroxyalkylated cellulose units incorporated into its structure and is suitable for synthesis of polyurethane foams. The properties of the foam were close to those of typical rigid polyuerethane foams used in industry. The foam showed good thermal resistance. Thermal exposure of obtained foam results in increase of compression strength. (c) 2020 Society of Chemical Industry (SCI)