Polyetherols and polyurethane foams from starch

Abstract

New method of synthesis of polyetherols from starch in aqueous solution was elaborated. Starch was converted into polyetherols by reactions with alkylene carbonates. The products are mixtures of starch-derived polyetherols and products of hydroxyalkylation of water. The elaborated method can be useful, eco-friendly synthetic route avoiding burdensome solvents. The polyetherols were characterized by IR, H NMR and MALDI-ToF spectroscopes and used to obtain rigid polyurethane foams. The properties of polyurethane foams obtained from such polyetherols were investigated. The polyurethane foams have apparent density, water uptake and polymerization shrinkage similar to the classic polyurethane foams. Some of obtained PUFs show improved thermal resistance; they stand long term heating at 175 °C. Furthermore, thermal exposure of obtained PUFs results in increase of their compression strength, which renders them valuable material for isolation. The polyurethane foam obtained from polyetherols synthesized in a reaction of starch with propylene carbonate showed moderate availability to biodegradation as was demonstrated by bioavailability tests with Bacillus subtilis.

Keywords

• Starch
• Hydroxyalkylation
• Polyurethane foams
• Properties
• Biodegradation