Hemicellulose Distribution in Pulp Fibers Anti Alkaline Extraction Rates

Publisher Website
Google Scholar
Abstract
Hemicellulose molecules available for fiber-fiber bonding should also be among those most readily extracted by alkali. With this premise in mind the extraction rates of hemicellulose from chemical pulps were examined and interpreted as being dependent on hemicellulose distribution. Measurements of the rates of extraction of glucuronoxylan and glucomannan from primarily southern pine oxygen pulps showed that the bulk of hemicellulose was not immediately available to extraction. After a few seconds of initial rapid extraction by 6% NaOH, removal rates quickly decreased but extraction continued indefinitely. Adsorbed hemicellulose by comparison was initially more rapidly extracted. About half of the hemicellulose most rapidly extracted from high-yield oxygen pulps was associated with lumens and large pores. The remaining half (perhaps 5% of the xylan and 2–3% of the glucomannan) was estimated to be the maximum amount potentially, but not necessarily, available for fiber-fiber bonding.