Effect of Hydrogen Peroxide on the Extraction of Components of Cedar Powder with Tetrabutylphosphonium Hydroxide Aqueous Solution at 60 degrees C

摘要

We successfully dissolved cedar powder with tetrabutylphosphonium hydroxide ([P-4 4 4 4]OH) aqueous solution at 60 degrees C. The dissolution was accelerated by the addition of H2O2. At the initial stage, cellulose was more soluble than hemicellulose and lignin. Both hemicellulose and lignin were gradually dissolved in this solution containing H2O2. Cellulose chains were revealed to be cut into shorter chains in this solution. The lignin network was also found to be partly broken at 60 degrees C. These steps induced components with higher-molecular-weight fractions that cannot be extracted with polar ionic liquids to dissolve. Also, low-molecular-weight fractions such as vanillin and 5-(hydroxymethyl)furfural were found in the resulting solution. Breakage of ether bonds of polysaccharides and lignin and further oxidation were attributed to the active oxygens generated from H2O2. The aqueous mixture reported here is a protocol that can be used to dissolve woody biomass under mild conditions.