Sodium hypophosphite

About: Sodium hypophosphite is a research topic. Over the lifetime, 1695 publications have been published within this topic receiving 15932 citations.

Flame Retardant Finishing of Cotton Fleece Fabric: Part III — The Combination of Maleic Acid and Sodium Hypophosphite

Abstract: 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...

Studies on electroless Ni–W–P and Ni–W–Cu–P alloy coatings using chloride-based bath

Abstract: In the present investigation ternary electroless Ni-W-P alloy coatings were prepared using alkaline citrate-based bath. Nickel chloride and sodium tungstate were used as nickel and tungsten sources, respectively, and sodium hypophosphite was used as a reducing agent. Deposits were characterized for their structure, morphology, chemical composition and microhardness. A single peak was obtained in XRD for ternary Ni-W-P alloy. Addition of 3 mM of copper chloride in the bath has resulted in a very smooth quaternary Ni-W-Cu-P alloy. Also, codeposition of copper in ternary alloy has increased the peak sharpness and the calculated grain sizes for ternary and quaternary deposits are 2.5 and 8.8 nm, respectively. XPS studies show that in ternary Ni-W-P deposits from the present bath nearly 60 at.% of tungsten is present in the elemental form, Wlt;supgt;0lt;/supgt;, as compared to that from nickel chloride and sulphate additives bath in which Wlt;supgt;0lt;/supgt; state is only 27 at.%. Addition of copper chloride to the present bath has increased this elemental form by nearly 10 at.% in the quaternary deposit. SEM micrographs show that ternary alloy films are nodular whereas quaternary alloy films are smooth and nodule-free. Microhardness measurements show a marginal difference in the hardness between ternary and quaternary deposits. [All rights reserved Elsevier]

Poly alcohol-based binder composition

Abstract: The present invention provides a binder composition comprising a low molecular weight polycarboxylic acid, such as maleic anhydride, and a low molecular weight poly alcohol, such as polyvinyl alcohol, that exhibits improved cure performance with reduced emissions without sacrificing the performance of the final product or complication the manufacturing process. The binder composition may also incorporate a cure catalyst or accelerant such as sodium hypophosphite.

Biomedical Textiles Through Multifunctioalization of Cotton Fabrics Using Innovative Methoxypolyethylene Glycol- N -Chitosan Graft Copolymer

Abstract: Multifunctioalization of cotton fabrics was developed by a novel finishing formulation. The method is based on chitosan-N-polyethylene glycol graft copolymer along with citric acid and sodium hypophosphite (SHP) as catalysts. Treatment of the cotton fabric resulted in the chemical attachment of the copolymer to the cotton fabric via bridging-based esterification where the latter involves reaction of one molecule of the polycarboxylic acid (citric acid) with both the amino group of the copolymer and the hydroxyl groups of cotton. Inclusion of the copolymer in the crosslinked structure of cotton as well as by hydrogen bonding and van der Waals forces are additionally possible. Synthesis of the copolymer was raised out by the reaction of chitosan with methoxy polyethylene glycol (MPEG) aldehyde followed by the reduction with sodium borohydride. MPEG was prepared by oxidation of PEG with acetic anhydride in dimethyl sulphoxide at room temperature. Methoxypolyethylene glycol-N-chitosan graft copolymer (MPEG-N-CTS) structure was confirmed by IR, NMR, X-RD and TGA techniques. The copolymer is soluble in water. The pad dry-cure method was used for the cotton fabrics treatment with aqueous solution of prepared copolymer along with citric acid and SHP. The so treated fabrics were monitored for copolymer content (expressed as N%), crease recovery, tensile strength, elongation at break, air permeability, water permeability, roughness, bursting strength and antibacterial activity. Fabric performances based on the outputs of these measurements advocate these multifunctionalized fabrics for use as medical textile.