Surface characteristics of NaOH-AQ wheat straw pulp fiber with xylanase pretreatment determined by ESCA

The surface characteristics of NaOH-AQ wheat straw pulp fiber during xylanase pretreatment was analyzed by ESCA, and the effect of xylanase treatment on wheat straw pulp properties with a short sequence HD was investigated. As determined by ESCA, on the surface of the wheat straw pulp treated with xylanase AU-PE89, the ratio of oxygen to carbon atom and the valent states of the carbon atom were markedly changed, which suggested that the chemical composition of pulp surface changed. It was also found that the brightness and strength properties of bleached NaOH-AQ wheat straw pulp was improved by xylanase pretreatment separately prior to H stage or D stage. The results showed that the NaOH-AQ wheat straw pulp can be bleached with XHD and HXD to brightness 75.8% ISO and 74.9% ISO, respectively, compared with 73.2% ISO bleached with HD. It turned out that the xylanase pretreatment resulted in complex structure between lignin and hemicelluloses and cellulose, thus brought about the improvement in pulp bleachability and brightness, which had a vital significance in studying the mechanism of wheat straw pulp with xylanase pretreatment.