The Experts below are selected from a list of 933 Experts worldwide ranked by ideXlab platform
Charles Q Yang - One of the best experts on this subject based on the ideXlab platform.
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the combination of itaconic acid and Sodium Hypophosphite as a new cross linking system for cotton
Industrial & Engineering Chemistry Research, 2012Co-Authors: Charles Q Yang, Huitao Peng, Xilie Wang, Shanyuan WangAbstract:In this research, we studied cross-linking of cotton fabrics using the combination of itaconic acid (ITA) and Sodium Hypophosphite (NaH2PO2). ITA, a bifunctional carboxylic acid, was able to esterify cotton cellulose to form a single ester linkage, but it was not able to form cross-linking between two cellulose molecules. In the presence of NaH2PO2, the amount of ester formed on cotton fabric was increased substantially and the esterification temperature of ITA was reduced. Therefore, NaH2PO2 functioned as a catalyst for esterification of cotton by ITA. Moreover, we found that wrinkle resistance of the cotton fabric was significantly improved when cotton fabrics were treated with the combination of ITA and NaH2PO2.We also found that phosphorus was bound to the treated cotton fabric and that the increase in the wrinkle recovery angle of the treated fabric was correlated to the increase in the amount of phosphorus bound to cotton. All the data indicated that H–P–H of Sodium Hypophosphite probably reacts wit...
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nonformaldehyde durable press finishing of cotton fabrics using the combination of maleic acid and Sodium Hypophosphite
Carbohydrate Polymers, 2012Co-Authors: Huitao Peng, Charles Q Yang, Shanyuan WangAbstract:Polycarboxylic acids have been used as nonformaldehyde crosslinking agents for cotton with Sodium Hypophosphite (NaH2PO2) as the catalyst to replace the formaldehyde-based dimethyloldihydroxyethleneurea (DMDHEU). Maleic acid (MA), an α, β-unsaturated bifunctional carboxylic acid, can esterify cotton but is not able to form crosslinking between two cellulose molecules by itself. In this research, we discovered that the wrinkle resistance of the cotton fabric treated with MA and NaH2PO2 was significantly increased and phosphorus was bound to cotton when the treated fabric was exposed to temperatures higher than that required for esterification of cotton by MA. Elevation of the fabric wrinkle resistance and increase in quantity of the phosphorus bound to cotton had similar dependency on curing temperature, on MA concentration, and on NaH2PO2 concentration. All the data support the hypothesis that H–P–(residual of NaH2PO2) added to >CC< of the MA already bound to cotton by esterification, thus forming a new crosslink between two cotton cellulose molecules. The cotton fabrics treated by MA/NaH2PO2 showed fabric wrinkle resistance similar to that treated with DMDHEU, but the breaking strength and tearing strength of the MA-treated cotton fabrics were significantly improved.
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cross linking cotton cellulose by the combination of maleic acid and Sodium Hypophosphite 2 fabric fire performance
Industrial & Engineering Chemistry Research, 2011Co-Authors: Charles Q Yang, Bojana VoncinaAbstract:Multifunctional carboxylic acids have been used as durable press finishing agents for cotton with Sodium Hypophosphite (NaH2PO2) as the most effective catalyst. In our previous research, we found that cellulose cross-linking takes place when cotton fabric treated with a combination of maleic acid and NaH2PO2 is cured at ≥150 °C. The data suggested that H−P−H of Hypophosphite likely reacts with >C═C< of the maleic acid already esterified with cotton cellulose, thus making it possible to form cross-linking on cotton. In this research, we studied the effect of the maleic acid (MA) and NaH2PO2 treatment on the fire performance of cotton using microscale combustion calorimetry. We found that esterification of cotton by MA reduces the flammability of the cotton cellulose. NaH2PO2 catalyzes the esterification of MA on cotton, thus further reducing the cotton fabric’s flammability by increasing esterification on cotton. The quantity of ester formed on cotton reaches the optimum range when the curing temperature i...
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cross linking cotton cellulose by the combination of maleic acid and Sodium Hypophosphite 1 fabric wrinkle resistance
Industrial & Engineering Chemistry Research, 2010Co-Authors: Charles Q Yang, Dongzhong Chen, Jinping GuanAbstract:Durable press finishing agents used to produce wrinkle-resistant cotton garments are cross-linking agents for cotton cellulose. Polycarboxylic acids have been the promising durable press finishing agents to replace the formaldehyde-based reagents when Sodium Hypophosphite (NaH2PO2) was used as the catalyst. In our previous research, we found that a polycarboxylic acid esterifies cotton cellulose by first forming a five-membered cyclic anhydride as a reactive intermediate. Maleic acid (MA) is a bifunctional carboxylic acid, therefore is not able to form the second cyclic anhydride intermediate once it forms the first ester linkage with cotton. However, we discovered that MA imparted wrinkle resistance to cotton fabrics when NaH2PO2 was present, thus indicating that MA was able to cross-link cotton. Sodium Hypophosphite functions as the catalyst for the esterification of cellulose by MA, and the esterification takes place at relatively low temperatures (≥130 °C). Esterification of MA forms single esterlinka...
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flame retardant finishing of cotton fleece fabric part iii the combination of maleic acid and Sodium Hypophosphite
Journal of Fire Sciences, 2008Co-Authors: Charles Q YangAbstract:Cotton fleece does not meet the federal flammability standard (16 CFR Part 1610: `Standard for the Flammability of Clothing Textiles') without chemical treatment. In this research, the chemical reactions of maleic acid (MA) on cotton in the presence of Sodium Hypophosphite (NaH2PO 2) and the use of the combination of MA and NaH2PO 2 as a flame retardant finishing system for cotton fleece are investigated. It has been found that MA esterifies cotton cellulose at relatively low temperatures in the presence of NaH2PO2 as catalyst, and that MA esterified to cotton is able to further react with NaH2PO 2 at higher temperatures (≥150°C), which bonds phosphorus to the cotton cellulose. The reactions between MA and NaH2PO2 on cotton also lead to the cross-linking of cotton cellulose. The treatment using the combination of MA and NaH2PO2 is effective in reducing the flammability of cotton fleece from `Class III' to `Class I' (16CFR1610). This is a nonformaldehyde and low cost flame retardant finishing system for co...
Shujuan Zhang - One of the best experts on this subject based on the ideXlab platform.
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synthesis of an iron phosphide catalyst based on sulfides and hydrodesulfurization property
Chemical Engineering Journal, 2015Co-Authors: Limin Song, Shujuan ZhangAbstract:Abstract Bulk and SiO 2 supported iron phosphide (FeP) samples were synthesized with a mixture of iron sulfide (FeS) and Sodium Hypophosphite (NaH 2 PO 2 ·H 2 O). The physical and chemical properties of the as-prepared FeP/SiO 2 were studied by X-ray powder diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy and thermal gravimetric analysis. Dibenzothiophene was effectively hydrodesulfurized over the as-synthesized FeP/SiO 2 (Fe: 10 wt.%). The as-prepared FeP/SiO 2 shows a higher activity than the FeP/SiO 2 obtained by the temperature-programmed reduction route. The Fe–P–S species constructed in situ may be responsible for the higher activity. The method is also feasibly applicable in synthesizing other transition metal phosphides.
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synthesis of highly active and porous nicop catalysts via directly thermal treatment of a mechanical mixing of nickel cobalt salts and Sodium Hypophosphite
Powder Technology, 2011Co-Authors: Limin Song, Shujuan ZhangAbstract:Abstract A new method for the preparation of bimetal phosphides was reported. Bulk and SiO 2 -supported porous NiCoP were obtained from the direct thermal treatment of precursors containing nickel, cobalt salts, and Sodium Hypophosphite mixed mechanically under flowing nitrogen. Compared with traditional H 2 -temperature-programmed reduction method, the method developed provided a simple one-step way to produce bimetal phosphides with a relatively low temperature. In the report, a possible preparation mechanism was discussed to form NiCoP. The route and mechanism could also be applied to the preparation of other bimetal phosphides. In comparison with the Ni 2 P/SiO 2 catalyst, the NiCoP/SiO 2 showed a higher hydrodesulfurization activity for dibenzothiophene.
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a versatile route to synthesizing bulk and supported nickel phosphides by thermal treatment of a mechanical mixing of nickel chloride and Sodium Hypophosphite
Powder Technology, 2011Co-Authors: Limin Song, Shujuan ZhangAbstract:Abstract Bulk and supported nickel phosphides were prepared by thermal treatment of a mechanical mixing of nickel chloride and Sodium Hypophosphite in a flowing N2. The samples were characterized using thermogravimetric analysis, X-ray diffraction, and inductively coupled plasma. The effect of different aspects on the Ni2P formation was primarily investigated. A rational mechanism was proposed for the selective formation of Ni2P. SiO2-supported Ni2P exhibits excellent hydrodesulfurization (HDS) activity for dibenzothiophene (DBT).
Manabu Node - One of the best experts on this subject based on the ideXlab platform.
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a raney nickel Sodium Hypophosphite combination system for reductive desulfurization without racemization of optically active secondary alcohol
Tetrahedron, 1997Co-Authors: Manabu Node, Kiyoharu Nishide, Yukihiro Shigeta, Kenichi Obata, Hiroaki Shiraki, Hideaki KunishigeAbstract:Abstract Sulfides and sulfoxides bearing an optically active secondary alcohol were desulfurized with a Raney nickel (W-2)-Sodium Hypophosphite combination system to give optically active alcohols in high yields without racemization . However, the combination system was not effective with sulfides which comprise an alkylthio group and the corresponding sulfoxides. This system exhibited the reductive desulfurization of benzylthio or phenylthio ether in the presence of a benzyl ether.
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reductive desulfurization using the raney nickel Sodium Hypophosphite combination system without racemization of a secondary alcohol
Tetrahedron Letters, 1996Co-Authors: Kiyoharu Nishide, Yukihiro Shigeta, Kenichi Obata, T Inoue, Manabu NodeAbstract:Abstract Thioethers bearing an optically active secondary alcohol were desulfurized with Raney nickel — Sodium Hypophosphite — acetate buffer system to give optically active alcohols without racemization in high yields. This Raney nickel combination system exhibited a unique desulfurization of benzylthio or phenylthio group in the presence of benzyl ether.
Ali Shamei - One of the best experts on this subject based on the ideXlab platform.
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a novel method for coating of carbon nanotube on cellulose fiber using 1 2 3 4 butanetetracarboxylic acid as a cross linking agent
Progress in Organic Coatings, 2012Co-Authors: Farbod Alimohammadi, Mazeyar Parvinzadeh Gashti, Ali ShameiAbstract:Abstract Carbon nanotubes (CNTs) were coated by the exhaustion method and stabilized on a cotton surface using 1,2,3,4-butanetetracarboxylic acid (BTCA) as a crosslinking agent and Sodium Hypophosphite (SHP) as a catalyst. The Influence of CNTs on the performance of the cellulose fiber was investigated using Fourier transform infrared spectrophotometer (FTIR), thermo-gravimetric analyzer, scanning electron microscope (SEM), zeta potential analyzer, reflectance spectroscope, wrinkle recovery tester and bacteriological culture tube. The possible interactions between CNTs, the cross-linking agent and cellulose functional groups at the surface were elucidated by FTIR spectroscopy. The results indicated that the stabilized CNTs modify the surface of the fibers and increase the thermal stability of the substrate. SEM showed a uniform coating of CNTs on the fiber surface.
Lei Hou - One of the best experts on this subject based on the ideXlab platform.
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Two-dimensional correlation infrared spectroscopy of heat-induced esterification of cellulose with 1,2,3,4-butanetetracarboxylic acid in the presence of Sodium Hypophosphite
Cellulose, 2019Co-Authors: Lei HouAbstract:The heat-induced esterification reaction between cellulose and 1,2,3,4-butanetetracarboxylic acid (BTCA), catalyzed with Sodium Hypophosphite (SHP) was investigated by FTIR spectroscopy in combination with the perturbation correlation moving window (PCMW) technique and two-dimensional correlation Infrared spectroscopy (2Dcos). Two main stages could be identified in the heating process between 30 and 160 °C for the reaction system. Weakening of hydrogen bonding interactions within polar groups, such as C=O and O–H, and water evaporation takes place in the first stage (30–100 °C). The reaction process, which consists of cyclic anhydride formation and esterification, between BTCA and cellulose gradually occurs after heating above 100 °C. It is believed that both the presence of SHP and heating, leading to hydrogen bond breakage, contribute to the formation of cyclic anhydrides and further esterification. Moreover, it is shown in the 2Dcos analysis that ester groups appear immediately after the formation of anhydrides, suggesting that the reaction happens in a progressive way. Furthermore, through PCMW maps, we find that the esterification reaction mainly occurs in the temperature region between 126 and 142 °C and is fastest at 132 °C.
