@article {2446, title = {Mill Trial of the New Bleaching Agent -THPS}, journal = {Pulp \& Paper-Canada}, volume = {110}, number = {7}, year = {2009}, note = {ISI Document Delivery No.: 508TWTimes Cited: 0Cited Reference Count: 31Hu, T. Q. Williams, T. Schmidt, J. A. James, B. R. Cavasin, R. Lewing, D.}, month = {Sep}, pages = {37-42}, type = {Article}, abstract = {An eight-day mill. trial of adding tetrakis(hydroxymethyl)phosphonium sulfate (THPS) (at 1.0 kg THPS/t pulp) to hydrosulfite (Y) bleaching of spruce SGW pulp shows an average, additional brightness gain of 2.0-2.3 ISO points without any bleach plant or paper machine process upsets. This additional brightness gain, sustained during subsequent one-year commercial implementation of the "THPS + Y" bleaching technology, allows the mill to reach brightness target during the difficult summer period, and to reduce the consumption of expensive brightness-enhancing additives for LWC papers. Overall estimated cost saving to the mill is $250,000/year.}, keywords = {bleach, bleaching, brightness, BRIGHTNESS STABILIZING AGENTS, CHEMISTRY, COMPOUNDS, COSTS, mechanical pulps, PHOSPHONIUM, SODIUM HYDROSULFITE, SULFATE, TERTIARY PHOSPHINES, TETRAKIS(HYDROXYMETHYL)PHOSPHONIUM}, isbn = {0316-4004}, url = {://000270960500008}, author = {Hu, Thomas Q. and Williams, T. and Schmidt, J. A. and James, Brian R. and Cavasin, R. and Lewing, D.} } @article {2446, title = {Mill Trial of the New Bleaching Agent -THPS}, journal = {Pulp \& Paper-Canada}, volume = {110}, number = {7}, year = {2009}, note = {ISI Document Delivery No.: 508TWTimes Cited: 0Cited Reference Count: 31Hu, T. Q. Williams, T. Schmidt, J. A. James, B. R. Cavasin, R. Lewing, D.}, month = {Sep}, pages = {37-42}, type = {Article}, abstract = {An eight-day mill. trial of adding tetrakis(hydroxymethyl)phosphonium sulfate (THPS) (at 1.0 kg THPS/t pulp) to hydrosulfite (Y) bleaching of spruce SGW pulp shows an average, additional brightness gain of 2.0-2.3 ISO points without any bleach plant or paper machine process upsets. This additional brightness gain, sustained during subsequent one-year commercial implementation of the "THPS + Y" bleaching technology, allows the mill to reach brightness target during the difficult summer period, and to reduce the consumption of expensive brightness-enhancing additives for LWC papers. Overall estimated cost saving to the mill is $250,000/year.}, keywords = {bleach, bleaching, brightness, BRIGHTNESS STABILIZING AGENTS, CHEMISTRY, COMPOUNDS, COSTS, mechanical pulps, PHOSPHONIUM, SODIUM HYDROSULFITE, SULFATE, TERTIARY PHOSPHINES, TETRAKIS(HYDROXYMETHYL)PHOSPHONIUM}, isbn = {0316-4004}, url = {://000270960500008}, author = {Hu, Thomas Q. and Williams, T. and Schmidt, J. A. and James, Brian R. and Cavasin, R. and Lewing, D.} } @article {2106, title = {The fate of phosphorus in the bleaching of spruce TMP with the new bleaching agent - THPS}, journal = {Holzforschung}, volume = {62}, number = {4}, year = {2008}, note = {ISI Document Delivery No.: 320ZETimes Cited: 1Cited Reference Count: 30Hu, Thomas Q. Yu, Eric James, Brian R. Marcazzan, Paolo}, pages = {389-396}, type = {Article}, abstract = {Tetrakis(hydroxymethyl)phosphonium sulfate (THPS) is a newly discovered, phosphorus-based bleaching agent that has been successfully tested in a pulp mill trial. The fate of phosphorus (P) and the chemistry in the course of THPS bleaching of a spruce TMP have been studied. The amount of P introduced into the THPS-bleached pulp depends on THPS dose and the bleaching conditions and it correlates well with the brightness gain. The P introduced into THPS-bleached pulp is covalently bonded to the pulp. The THPS-bleached and tetraethylphosphonium chloride-treated pulps have been additionally treated with calcium chloride before P analysis, and the results of these experiments support the covalent bonding hypothesis. Bleaching with 0.1 and 3.0\% THPS (\% based on oven-dried pulp) at 60 and 110 degrees C leads to pulps with 0.13 and 2.17 mg P g(-1) pulp, respectively, which corresponds to 0.08 and 1.4\% THPS. More precisely, P is covalently bonded to lignin chromophores, such as lignin coniferaldehydes. This was found by P-content analysis, UV-visible spectroscopy, and P-31 {H-1} NMR studies of a crude milled wood lignin (crude MWL) and a partially purified MWL isolated from a THPS-bleached pulp.}, keywords = {bleaching, brightness, BRIGHTNESS STABILIZING AGENTS, CHEMISTRY, CHROMOPHORES, conk, feraldehyde, lignins, mechanical pulps, phosphonium compounds : phosphorus, tetrakis(hydroxymethyl) phosphonium sulfate, thermomechanical pulps}, isbn = {0018-3830}, url = {://000257273000003}, author = {Hu, Thomas Q. and Yu, E. and James, Brian R. and Marcazzan, P.} } @article {2106, title = {The fate of phosphorus in the bleaching of spruce TMP with the new bleaching agent - THPS}, journal = {Holzforschung}, volume = {62}, number = {4}, year = {2008}, note = {ISI Document Delivery No.: 320ZETimes Cited: 1Cited Reference Count: 30Hu, Thomas Q. Yu, Eric James, Brian R. Marcazzan, Paolo}, pages = {389-396}, type = {Article}, abstract = {Tetrakis(hydroxymethyl)phosphonium sulfate (THPS) is a newly discovered, phosphorus-based bleaching agent that has been successfully tested in a pulp mill trial. The fate of phosphorus (P) and the chemistry in the course of THPS bleaching of a spruce TMP have been studied. The amount of P introduced into the THPS-bleached pulp depends on THPS dose and the bleaching conditions and it correlates well with the brightness gain. The P introduced into THPS-bleached pulp is covalently bonded to the pulp. The THPS-bleached and tetraethylphosphonium chloride-treated pulps have been additionally treated with calcium chloride before P analysis, and the results of these experiments support the covalent bonding hypothesis. Bleaching with 0.1 and 3.0\% THPS (\% based on oven-dried pulp) at 60 and 110 degrees C leads to pulps with 0.13 and 2.17 mg P g(-1) pulp, respectively, which corresponds to 0.08 and 1.4\% THPS. More precisely, P is covalently bonded to lignin chromophores, such as lignin coniferaldehydes. This was found by P-content analysis, UV-visible spectroscopy, and P-31 {H-1} NMR studies of a crude milled wood lignin (crude MWL) and a partially purified MWL isolated from a THPS-bleached pulp.}, keywords = {bleaching, brightness, BRIGHTNESS STABILIZING AGENTS, CHEMISTRY, CHROMOPHORES, conk, feraldehyde, lignins, mechanical pulps, phosphonium compounds : phosphorus, tetrakis(hydroxymethyl) phosphonium sulfate, thermomechanical pulps}, isbn = {0018-3830}, url = {://000257273000003}, author = {Hu, Thomas Q. and Yu, E. and James, Brian R. and Marcazzan, P.} } @article {1418, title = {A new class of bleaching and brightness stabilizing agents. Part III: Brightness stabilization of mechanical pulps}, journal = {Journal of Pulp and Paper Science}, volume = {32}, number = {3}, year = {2006}, note = {ISI Document Delivery No.: 101XNTimes Cited: 8Cited Reference Count: 29Hu, T. Q. James, B. R. Yawalata, D. Ezhova, M. B.}, month = {Jul-Sep}, pages = {131-136}, type = {Article}, abstract = {Recently, we discovered that water-soluble tertiary hydroxyalkyl phosphines and quaternary hydroxymethyl phosphonium salts were capable of providing a bleaching effect similar to or higher than that achievable with hydrosulphite on mechanical pulps over a wide range of pH, consistency and temperature. Now, we have found that mechanical pulps bleached with these phosphorus (P) compounds are more stable than those bleached with hydrosulphite, not only when exposed to heat and moisture, but also during ambient dark storage. One of the P compounds, tris(hydroxypropyl)phosphine (THPP), P(CH2CH2CH2OH)(3), is also effective in providing additional brightness gains to, and in improving the light stability of papers made from peroxide-bleached mechanical pulps.}, keywords = {bleached pulps, bleaching, brightness, HIGH-YIELD PULPS, LIGHT, mechanical pulps, PAPER, phosphorus compounds, REVERSION, stabilizers, YELLOWING INHIBITOR}, isbn = {0826-6220}, url = {://000241774700003}, author = {Hu, Thomas Q. and James, Brian R. and Yawalata, D. and Ezhova, M. B.} } @article {1418, title = {A new class of bleaching and brightness stabilizing agents. Part III: Brightness stabilization of mechanical pulps}, journal = {Journal of Pulp and Paper Science}, volume = {32}, number = {3}, year = {2006}, note = {ISI Document Delivery No.: 101XNTimes Cited: 8Cited Reference Count: 29Hu, T. Q. James, B. R. Yawalata, D. Ezhova, M. B.}, month = {Jul-Sep}, pages = {131-136}, type = {Article}, abstract = {Recently, we discovered that water-soluble tertiary hydroxyalkyl phosphines and quaternary hydroxymethyl phosphonium salts were capable of providing a bleaching effect similar to or higher than that achievable with hydrosulphite on mechanical pulps over a wide range of pH, consistency and temperature. Now, we have found that mechanical pulps bleached with these phosphorus (P) compounds are more stable than those bleached with hydrosulphite, not only when exposed to heat and moisture, but also during ambient dark storage. One of the P compounds, tris(hydroxypropyl)phosphine (THPP), P(CH2CH2CH2OH)(3), is also effective in providing additional brightness gains to, and in improving the light stability of papers made from peroxide-bleached mechanical pulps.}, keywords = {bleached pulps, bleaching, brightness, HIGH-YIELD PULPS, LIGHT, mechanical pulps, PAPER, phosphorus compounds, REVERSION, stabilizers, YELLOWING INHIBITOR}, isbn = {0826-6220}, url = {://000241774700003}, author = {Hu, Thomas Q. and James, Brian R. and Yawalata, D. and Ezhova, M. B.} } @article {887, title = {A new class of bleaching and brightness stabilizing agents. Part I: Bleaching of mechanical Pulps}, journal = {Journal of Pulp and Paper Science}, volume = {30}, number = {8}, year = {2004}, note = {ISI Document Delivery No.: 860FETimes Cited: 14Cited Reference Count: 43}, month = {Aug}, pages = {233-240}, type = {Article}, abstract = {We have discovered a new class of bleaching and brightness stabilizing agents for mechanical and chemical pulps. The new agents are water-soluble tertiary phosphines and quaternary hydroxymethyl phosphonium salts, such as tris(hydroxymethyl)phosphine (THP), P(CH2OH)(3), and tetrakis(hydroxymethyl)phosphonium chloride (THPC), [P(CH2OH)(4)]Cl. For the bleaching of mechanical pulps, such phosphorus compounds have a bleaching power similar to that of sodium hydrosulphite, but they can be used over a wider range of pH (4.3-9.3), temperature (20-130degreesC) and consistency(e.g. 1.5-20\%) without the need for the removal of oxygen or transition metal ions. Furthermore, pulps bleached with this new class of bleaching agents show higher heat and moisture stability than those bleached with sodium hydrosulphite or alkaline hydrogen peroxide. Bleaching of mechanical pulps with THP or THPC is accompanied by a reduction of the absorption coefficient of the pulps.}, keywords = {bleach, bleaching, DISULFIDES, evaluation, mechanical pulps, PERFORMANCE, phosphines, phosphonium compounds, pulp properties, REDUCTION, stabilizers, tertiary compounds}, isbn = {0826-6220}, url = {://000224327100005}, author = {Hu, Thomas Q. and James, Brian R. and Yawalata, D. and Ezhova, M. B.} } @article {887, title = {A new class of bleaching and brightness stabilizing agents. Part I: Bleaching of mechanical Pulps}, journal = {Journal of Pulp and Paper Science}, volume = {30}, number = {8}, year = {2004}, note = {ISI Document Delivery No.: 860FETimes Cited: 14Cited Reference Count: 43}, month = {Aug}, pages = {233-240}, type = {Article}, abstract = {We have discovered a new class of bleaching and brightness stabilizing agents for mechanical and chemical pulps. The new agents are water-soluble tertiary phosphines and quaternary hydroxymethyl phosphonium salts, such as tris(hydroxymethyl)phosphine (THP), P(CH2OH)(3), and tetrakis(hydroxymethyl)phosphonium chloride (THPC), [P(CH2OH)(4)]Cl. For the bleaching of mechanical pulps, such phosphorus compounds have a bleaching power similar to that of sodium hydrosulphite, but they can be used over a wider range of pH (4.3-9.3), temperature (20-130degreesC) and consistency(e.g. 1.5-20\%) without the need for the removal of oxygen or transition metal ions. Furthermore, pulps bleached with this new class of bleaching agents show higher heat and moisture stability than those bleached with sodium hydrosulphite or alkaline hydrogen peroxide. Bleaching of mechanical pulps with THP or THPC is accompanied by a reduction of the absorption coefficient of the pulps.}, keywords = {bleach, bleaching, DISULFIDES, evaluation, mechanical pulps, PERFORMANCE, phosphines, phosphonium compounds, pulp properties, REDUCTION, stabilizers, tertiary compounds}, isbn = {0826-6220}, url = {://000224327100005}, author = {Hu, Thomas Q. and James, Brian R. and Yawalata, D. and Ezhova, M. B.} } @article {2891, title = {THE EFFECT OF METAL-COMPLEXES IN THE ELECTROCHEMICALLY MEDIATED OXYGEN BLEACHING OF WOOD PULP}, journal = {Tappi Journal}, volume = {76}, number = {10}, year = {1993}, note = {ISI Document Delivery No.: MA717Times Cited: 13Cited Reference Count: 34}, month = {Oct}, pages = {139-147}, type = {Article}, abstract = {The electrochemical behavior of transition-metal complexes is correlated with their effect in promoting electrochemically mediated oxygen bleaching of unbleached kraft softwood pulp. Ions of Fe, Mn, Co, Cr, Cu, and V with various ligands were examined in oxygen bleaching experiments at pH 9.4, 11.2, and 14. Only ferricyanide, iron/2,2{\textquoteright}-dipyridyl, and ferrate exhibited significant synergistic effects with oxygen. Chemicals with reduction potential lower than that of the ferrocyanide couple at the pH of reaction, or those without reversible redox behavior, showed no synergistic effect. A mechanism is proposed in which the reaction of lignin with oxygen is initiated by oxidation of lignin with the higher valent species of the metal redox couple The metal redox couple may also catalyze peroxide decomposition via Fenton chemistry to generate the hydroxyl radical and thus promote degradation of cellulose.}, keywords = {AMPEROMETRY, BIBLIOGRAPHIES, bleaching, CATALYSTS, ELECTROCHEMISTRY, OXYGEN, REDOX POTENTIAL, transition metals}, isbn = {0734-1415}, url = {://A1993MA71700024}, author = {Perng, Y. S. and Oloman, C. W. and James, Brian R.} }