Sodium sulfide

About: Sodium sulfide is a research topic. Over the lifetime, 2851 publications have been published within this topic receiving 27733 citations. The topic is also known as: disodium sulfide.

Polyphenylene sulfide resin composition

Abstract: PURPOSE:To obtain a composition having stable melt fluidity of melt blend, melt molding properties, dimensional accuracy and sliding characteristics, by blending a polyphenylene sulfide resin having specific melt viscosity with an epoxy resin moldable in a molten state under heating. CONSTITUTION:A composition consisting of (A) 100pts.wt. polyphenylene sulfide resin having =90mol.% repeating unit shown by the formula obtained by reacting sodium sulfide with p-dichlorobenzene in an amide solvent, (B) 10-100pts.wt. heat-resistant epoxy resin (main agent and curing agent) moldable in a molten state under heating, preferably one containing a high-molecular weight novolak phenolic resin as a curing agent and (C) 0-250pts.wt., preferably 30-250pts.wt. filler and having a melt flow difference of the blend of the components A and B between 6min retention time and 30min retention time of <=0.7 based on the value of 6min retention time.

Bimechanistic phase transfer catalyzed polythioetherification

Abstract: Relative concentrations of catalysts, sulfide catalyst structure, and organic phase monomer concentration were studied for the bimechanistic phase transfer catalyzed (BPTC) polymerization of aqueous sodium sulfide with 1,8-dibromooctane (DBO). BPTC is a new phase transfer mechanism which combines the effects of normal phase transfer with “inverse” phase transfer catalyzed reactions. Two catalysts are used: an ammonium salt and a cyclic or acyclic sulfide. With hexadecyltrimethylammonium chloride (CTMAC) and tetrahydrothiophene (THT), the optimum catalyst concentrations were found to be 10 mol-% and 5 mol-%, respectively, per DBO, but each was independent of the other. Diluting the monomer with o-dichlorobenzene did not significantly alter the mechanism's profile, but expectedly lowered obtainable molecular weight. Of five sulfide catalysts examined, pentamethylene sulfide and dimethyl sulfide were the best, producing the highest molecular weight polyaliphatic sulfides with polydispersities Mw/Mn of ca. 1,3.

Effects of selected reducing agents on microbiologically mediated reductive dechlorination of aroclor® 1242

Abstract: The effect of various chemical reducing agents on the anaerobic microbial reductive biotransformation of polychlorinated biphenyls (PCBs) was investigated using Aroclor® 1242 at a concentration of 600 μg/g soil and microorganisms eluted from Hudson River sediments. The investigation sought to determine how various reducing agents influenced PCB dechlorination rates, patterns, and acclimation periods. Three reducing agents were incorporated into culture media : amorphous ferrous sulfide, sodium sulfide with sodium thioglycollate, and sodium sulfide with amorphous ferrous sulfide. All cultures were incubated statically under methanogenic conditions and ambient incubation temperatures of about 20°C. Cultures utilizing both sodium sulfide and ferrous sulfide together demonstrated the most extensive removal of meta- and para-chlorines, the highest average dechlorination rate, the greatest dechlorination of tri- and tetrachlorinated biphenyls, and the greatest accumulation of dichlorobiphenyl homologues. Overall, treatments incorporating ferrous sulfide, alone or in combination with sodium sulfide, demonstrated the ability to more effectively dechlorinate tri-ortho-substituted tetrachlorobiphenyls and pentachlorobiphenyls which had commonly positioned chlorines. Under these same conditions, dichlorobiphenyls, which are more amenable to aerobic dechlorination conditions, increased from 25% (molar basis) initially to levels greater than 60%.

Method for obtaining nickel sulfide from pickled liquor of laterite nickel ore

Abstract: The invention provides a method to obtain nickel sulfide from pickle liquor of laterite nickel mine. Wherein, the leachate has pH value not less than 1.7 with nickel and sodium sulfide added for the mass ratio 1:3-8; mixing evenly, controlling the nickel ion concentration less than 0.02g/L and filtering; adding water into the residue with ratio for solid and liquid of 1:2, clearing, filtering and obtaining the product; then, neutralizing the filtrate to pH value as 2-4 for recycle or release. This method can obtain high-grade product and the nickel deposition rate can reach 99.5% or more.

Poly(phenylene sulfide): Synthesis from 1,4‐dibromobenzene and sodium sulfide

Abstract: A new route to synthesize poly(p-phenylene sulfide) by nucleophilic substitution of 1,4-dibromobenzene with sodium sulfide in N-methylpyrrolidone is described. Kinetic evaluation shows the reaction to be of second order with two distinctive rate constant regimes. The first rate constant is higher and is operative until 50% conversion, whereas in the second regime (between 50 and 92% conversion) the rate is slower. The kinetics of this route is compared under identical conditions with the conventional synthesis based on 1,4-dichloro benzene and sodium sulfide.