@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 {1230, title = {Separation of porphyrin-based photosensitizer isomers by laser-induced fluorescence capillary electrophoresis}, journal = {Electrophoresis}, volume = {26}, number = {20}, year = {2005}, note = {ISI Document Delivery No.: 982VMTimes Cited: 3Cited Reference Count: 43}, month = {Oct}, pages = {3861-3868}, type = {Article}, abstract = {Methods for the separation of photosensitizer isomers, such as benzoporphyrin derivative monoacid, benzoporphyrin ethyl monoacid, 2-[1-hexyloxyethyl]-2-devinylpyropheophorbide-a, diethyleneglycol diester benzoporphyrin derivative, tin ethyl etiopurpurin, and phthalocyanine tetrasulfonate, have been systematically developed by CE. Detection was accomplished by UV absorption at 214 nm or by LIF with excitation at 442/488 nm and emission at 690 nm. The effects of three major experimental parameters of buffer types, organic solvents, and surfactant additives are described. The optimized separation conditions were determined so as to provide satisfactory separation efficiency and analysis time. The methods are shown to be suitable for the separation and determination of porphyrin and phthalocyanines regioisomers, diastereoisomers, and enantiomers.}, keywords = {chiral additives, CHLORIN, DERIVATIVES, EFFICACY, ENANTIOMERS, FLUORESCENCE DETECTION, FRACTION, LIGHT, PANCREATIC-CANCER CELLS, PERFORMANCE LIQUID-CHROMATOGRAPHY, pharmacokinetics, PHOTODYNAMIC THERAPY, PHTHALOCYANINES, porphyrins, regioisomers}, isbn = {0173-0835}, url = {://000233189700008}, author = {Peng, X. J. and Sternberg, E. and Dolphin, D.} } @article {5136, title = {Tetrazole ethers from lignin model phenols: synthesis, crystal structures, and photostability}, journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie}, volume = {79}, number = {8}, year = {2001}, note = {ISI Document Delivery No.: 473WGTimes Cited: 1Cited Reference Count: 24}, month = {Aug}, pages = {1201-1206}, type = {Article}, abstract = {{The phenolic OH moiety in lignin is one of the key functional groups responsible for the photo-induced yellowing of mechanical wood pulps and papers. To evaluate new protective groups for the stabilization of lignin phenols, the model compounds, 2-methoxy-4-propylphenol (1) and 4-hydroxy-3-methoxyacetophenone (2) were reacted with 5-chloro-1-phenyl-1H-tetrazole to give the corresponding tetrazole ethers 1{\textquoteright} and 2{\textquoteright}, respectively, that were then studied for their photostability. The synthesis of these ethers was more efficient than that of alkyl ethers because of less hydrolysis of the alkylating agent under the reaction conditions. Compounds 1{\textquoteright} and 2{\textquoteright} were fully characterized, including X-ray crystal structure analyses. Crystals of 1{\textquoteright} and 2{\textquoteright} were monoclinic of space groups P2(1)/c and P2(1)/a, respectively. For 1{\textquoteright}: a = 9.8679(6)}, keywords = {ALKYLATION, ETHERS, HIGH-YIELD PULPS, LIGHT, LIGNIN MODEL COMPOUNDS, METHYLATION, PHENOLS, yellowing inhibition}, isbn = {0008-4042}, url = {://000171071400001}, author = {Lu, A. Z. and Hu, Thomas Q. and Osmond, D. A. and Patrick, B. O. and James, Brian R.} } @article {5136, title = {Tetrazole ethers from lignin model phenols: synthesis, crystal structures, and photostability}, journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie}, volume = {79}, number = {8}, year = {2001}, note = {ISI Document Delivery No.: 473WGTimes Cited: 1Cited Reference Count: 24}, month = {Aug}, pages = {1201-1206}, type = {Article}, abstract = {{The phenolic OH moiety in lignin is one of the key functional groups responsible for the photo-induced yellowing of mechanical wood pulps and papers. To evaluate new protective groups for the stabilization of lignin phenols, the model compounds, 2-methoxy-4-propylphenol (1) and 4-hydroxy-3-methoxyacetophenone (2) were reacted with 5-chloro-1-phenyl-1H-tetrazole to give the corresponding tetrazole ethers 1{\textquoteright} and 2{\textquoteright}, respectively, that were then studied for their photostability. The synthesis of these ethers was more efficient than that of alkyl ethers because of less hydrolysis of the alkylating agent under the reaction conditions. Compounds 1{\textquoteright} and 2{\textquoteright} were fully characterized, including X-ray crystal structure analyses. Crystals of 1{\textquoteright} and 2{\textquoteright} were monoclinic of space groups P2(1)/c and P2(1)/a, respectively. For 1{\textquoteright}: a = 9.8679(6)}, keywords = {ALKYLATION, ETHERS, HIGH-YIELD PULPS, LIGHT, LIGNIN MODEL COMPOUNDS, METHYLATION, PHENOLS, yellowing inhibition}, isbn = {0008-4042}, url = {://000171071400001}, author = {Lu, A. Z. and Hu, Thomas Q. and Osmond, D. A. and Patrick, B. O. and James, Brian R.} }