TY - JOUR
T1 - Improved selectivity of oxygen bleaching through use of chemical additives
AU - Jewell, Melody
AU - Tschirner, Ulrike
PY - 2001/12/1
Y1 - 2001/12/1
N2 - Oxygen bleaching is traditionally known to result in loss of strength due to poor selectivity. The purpose of this research is to investigate two different additives (magnesium D-gluconate and tetrasodium 1-Hydroxyethylidene-1,1-diphosphonic acid (HEDP)) as to their impact on the selectivity of oxygen bleaching. The effectiveness of the additives was gauged by measurement of paper strength properties, pulp viscosity, carboxyl group content, carbohydrate content, and generation of hydroxyl radicals. The initial results show that at a given KAPPA number, HEDP addition produces a higher brightness, viscosity and bonding strength than control pulps and reduces the amount of calcium, manganese, aluminum and zinc present. HEDP addition also increases the amount of carbohydrates retained in the pulp, likely caused by a reduction in the generation of hydroxyl radicals. The addition of gluconate produced pulps with a lower viscosity than the control, but higher bonding strength and brightness. Carbohydrate analysis showed a lower carbohydrate/lignin ratio, however, a decrease in hydroxyl radical generation was observed. These results suggest that the HEDP addition is a more suitable additive for oxygen bleaching than magnesium gluconate.
AB - Oxygen bleaching is traditionally known to result in loss of strength due to poor selectivity. The purpose of this research is to investigate two different additives (magnesium D-gluconate and tetrasodium 1-Hydroxyethylidene-1,1-diphosphonic acid (HEDP)) as to their impact on the selectivity of oxygen bleaching. The effectiveness of the additives was gauged by measurement of paper strength properties, pulp viscosity, carboxyl group content, carbohydrate content, and generation of hydroxyl radicals. The initial results show that at a given KAPPA number, HEDP addition produces a higher brightness, viscosity and bonding strength than control pulps and reduces the amount of calcium, manganese, aluminum and zinc present. HEDP addition also increases the amount of carbohydrates retained in the pulp, likely caused by a reduction in the generation of hydroxyl radicals. The addition of gluconate produced pulps with a lower viscosity than the control, but higher bonding strength and brightness. Carbohydrate analysis showed a lower carbohydrate/lignin ratio, however, a decrease in hydroxyl radical generation was observed. These results suggest that the HEDP addition is a more suitable additive for oxygen bleaching than magnesium gluconate.
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M3 - Conference article
AN - SCOPUS:0142187225
SN - 0275-0899
SP - 19
EP - 47
JO - Pulping Conference, Proceedings of the Technical Association of the Pulp and Paper Industry
JF - Pulping Conference, Proceedings of the Technical Association of the Pulp and Paper Industry
T2 - Proceedings of the 2001 TAPPI Pulping Conference
Y2 - 4 November 2001 through 7 November 2001
ER -