Liquefaction of Bagasse and Preparation of Rigid Polyurethane Foam from Liquefaction Products

Bagasse was liquefied in the mixture of polyethylene glycol 400 (PEG 400) and glycerin as the liquefying reagent in the presence of sulfuric acid as catalyst at 150 degrees C under atmospheric pressure for 2 h. The liquefaction products, having the hydroxyl number of 300 similar to 450 mg KOH/g and viscosity of 1867-6986 mPa s at 25 degrees C, can be used as the polyol component to replace a part of traditional polyether polyol in the preparation of polyurethane foam. Rigid polyurethane foams were made from liquefied bagasse and diisocyanates catalyzed by dibutyltin dilaurate and triethylenediamine. The foams containing bio-polyol presented higher compressive strength and higher density than normal polyurethane foams did. The flame resistance of the polyurethane foam was improved by increasing the liquefied bagasse and flame retardant. The addition of liquefied bagasse into the foaming mixture resulted in enhanced degradation temperature of the polyurethane foam. Scanning electron microscopy (SEM) images suggested that the polyurethane foam containing liquefied bagasse had smooth surface and homogeneous foam structure.