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Influence of cations and borate on the alkaline extraction of xylan and glucomannan from pine pulps
Author(s) -
Scott Ralph W.
Publication year - 1989
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1989.070380512
Subject(s) - glucomannan , xylan , chemistry , cellulose , pulp (tooth) , swelling , kraft process , nuclear chemistry , boron , lignin , organic chemistry , kraft paper , materials science , biochemistry , composite material , medicine , pathology
Southern pine pulp fibers were extracted with Na, K, and Li hydroxides at several concentrations from 0.5 to 4.0 m (molal). The amounts of extracted xylan and glucomannan increased with the swelling of the cellulose structure up to 2.0–2.5 m . The addition of H 3 BO 3 to alkaline solutions produced the B(OH) − 4anion, which had less swelling power than OH − . It was not effective for removal of xylan except for some very accessible xylan of holocellulose. Removal of xylan from chemical pulps depended upon OH − in molar excess over H 3 BO 3 . In the same extractions, glucomannan removal was enhanced by B(OH) − 4alone and further increased by additional OH − . The formation of anions (carboxylate in xylan and borate complex of glucomannan) appeared to be important for the release of polymer from within the cellulose structure. Some glucomannan was more accessible in oxygen pulp than in holocellulose. The resorbed xylan of kraft pulp was less accessible than the xylans of either holocellulose or oxygen pulp.