Adsorption of Chemically Modified Xylans on Eucalyptus Pulp and Its Effect on the Pulp Physical Properties

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• 作者：Teresa Cristina Fonseca Silva ; Jorge Luiz Colodette ; Lucian A. Lucia ; Rubens Chaves de Oliveira ; Fla虂via Natalino Oliveira ; Luis Henrique Mendes Silva
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2011
• 出版时间：January 19, 2011
• 年：2011
• 卷：50
• 期：2
• 页码：1138-1145
• 全文大小：312K
• 年卷期：v.50,no.2(January 19, 2011)
• ISSN：1520-5045

文摘

Three different birchwood-based xylan biomaterials were used in the current study to deconvolve the heretofore unknown effects of these modified adsorbed xylans on the processability of eucalyptus pulp: a 4-O-methylglucuronic acid xylan (MeGlcA-xylan); then, the MeGlc moiety was modified to provide an enriched hexenuronic acid xylan (HexA-xylan) and a low uronic acid content xylan (LowUrA-xylan). The study illustrates how the composition of xylan, in terms of the type and content of uronic acid, strongly influences the physical properties of cellulose fibers. NMR was used to confirm these structures and their M_ws were measured by gel permeation chromatography. The three different xylan types were adsorbed onto bleached kraft pulp under controlled times and temperatures and examined by atomic force microscopy and scanning electron microscopy. It was found that LowUrA-xylan had greater adsorption on eucalyptus pulp, especially at high temperatures and times, while HexA-xylan adsorbed more onto eucalyptus pulp than MeGlcA-xylan. Water retention values of xylan-enriched eucalyptus pulps increased, while their hornification decreased. In general, xylan-enriched pulps demonstrated improved processability (beatibility) while displaying acceptable physical properties. These findings may have important implications for the overall efficiency and energetics of downstream biomass transformation processes such as pretreatment within the context of a biofuel application.