Sorption of Hemicelluloses on Cellulose Fibres. Pt. 2. Sorption of Glucomannan

Abstract

KeywordsThe sorption of pine glucomannan on cotton fibres was investigated as regards the reaction con-Cellulose ditions. The sorption was found to follow the Freundlich isotherm, the concentration thereby Cotton affecting the sorption to a high extent. An opening of the fibre structure by beating resulted in an Fibres increased sorption which correlated well with the swelling of the fibres but less with the increase Hemicellulose * n ^^r e sur^ace area measured by nitrogen adsorption. A decrease in DP of the solid phase also Mannan influenced the sorption positively, the effect remaining after reduction of the sorbent. This indi-Polysaccharides cates an influence of the crystallinity of the sorbent on the sorption and/or an opening of the Sorption fibre structure. Desorption ^ decrease in pH of the liquor phase did not affect the sorption to any higher extent. Desorption experiments showed that the sorbed molecules were affected about equal by the alkalinity and the temperature of the liquor phase.

The Role of Trichoderma reesei Xylanase and Mannanase in the Treatment of Softwood Kraft Pulp Prior to Bleaching

“…According to Luce to a minor endoglucanase II inpurity in the manna-(1964) the concentration of glucomannan is higher on nase preparate. When both enzymes were used either the surface of the fibres, due to relocation, as was simultaneously or stepwise, the bleachability was suggested by Hansson (1970). The sorption of gluco-further improved and the kappa number was reduced mannan on cellulose has been found to proceed faster to 15.4 or 14.7, respectively, and the brightness was inand also to a greater extent than the sorption of xylan creased from 43.1% to 44.9 and 45.4, respectively.…”

“…Thus in pine kraft pulp the major hemicellulosic component is xylan, in contrast to the original wood (Sjöström 1977). However, reprecipitation of part of the dissolved glucomannans on pulp has also been proposed to occur (Yundt 1951;Hansson 1970), although solubilized glucomannan molecules dissolved in alkali are believed to be degraded in a very short time at 130°C (Yllner et al 1957;Aurell and Hartler 1965). The redeposited hemicellulose and lignin polymers have also been suggested to be chemically linked to each other (Yamasaki et al 1981; Iversen andWännström 1986).…”

Extraction, Addition and Characterization of Hemicelluloses from Corn Cobs to Development of Paper Properties

“…These structures would be responsible for the difficulty of extraction and purification of xylan and the digestion time cereal grains (Silva et al, 1998). Several studies have been carried out showing the processes of isolation of hemicelluloses (Yllner and Enström, 1956;Yllner and Enström, 1957;Aurell, 1965;Hansson and Hartler, 1969;Henriksson and Gatenholm, 2001;Schönberg et al, 2001;Linder et al, 2003;Danielsson and Lindström, 2005;Danielsson, 2007;Köhnke and Gatenholm, 2007;Köhnke et al, 2008;Muguet et al, 2010;Silva, 2011) and the relationship between the cellulose and hemicellulose levels in paper properties (Schönberg et al, 2001;Danielsson and Lindström, 2005;Köhnke and Gatenholm, 2007;Köhnke et al, 2008;Muguet et al, 2010;Milanez et al, 1982;Molin and Teder, 2002;Anjos et al, 2005;Molina et al, 2008;Manfredi and Oliveira, 2010).…”

Adsorption of cationized barley husk xylan on kraft pulp fibres: influence of degree of cationization on adsorption characteristics

“…However, the level of xylan-cellulose interaction has been shown to depend on xylan molecular structure (e.g. Hansson and Hartler 1969;Köhnke and Gatenholm 2007;Kabel et al 2007; Köhnke et al 2008), which is dependent on botanical origin and the isolation procedure. If a high degree of xylan adsorption is desired, the xylan polymer may be chemically modified to improve interaction with anionic pulp fibres.…”