Polyfunctional Anion Exchangers Based on Copolymers of Allyl Glycidyl Ether and Polyamines

Polyfunctional anion exchangers were prepared by copolymerization of allyl glycidyl ether with polyamines in the presence of a promoter. The synthesis conditions were optimized. The composition and physicochemical features of the resins prepared were studied.     

Redox Ion Exchangers Based on Pyridinecarbonitriles

Thermal polymerization of o-, m-, and p-pyridinecarbonitriles and their derivatives under the action of Friedel-Crafts catalysts and binary catalysts was studied. The characteristics of the resulting polymers were determined.     

Transport Properties of Plasticized Membranes Based on Organic Ion Exchangers

Transport properties of ion-exchange membranes selective to surface-active substances are studied. The membranes are based on assorted electrode-active compounds, such as Methyl Green–dodecyl sulfate and cetylpyridinium–tetraphenylborate, which exhibit anion or cation selectivity, and cetylpyridinium–dodecyl sulfate, which displays cation–anion selectivity. On the basis of the data obtained with the electroconductivity, EMF, and applied-voltage methods, a conclusions is drawn about the majority charge carriers in the membranes and it is shown that the processes at the membrane/solution interface are reversible.     

Chromatography of Uranium on High-Performance Ion Exchangers

Abstract

The potential of high-performance liquid chromatography (HPLC) for the determination of U(VI) in ground waters and urine has been examined under a variety of HPLC experimental conditions. Conventional cross-linked and bonded-phase ion exchangers, both cation and anion, were studied with aqueous mobile phases containing tartrate, citrate, or α-hydroxyisobutyrate. The best chromatography was obtained on bonded-phase cation exchangers with an α-hydroxyisobutyrate eluent. The metal ions were detected either by visible spectrophotometry after a post-column reaction with a complexing reagent, or with a polarographic detector. Dectection after post-column reaction gave the best sensitivity; the detection limit (2 × baseline noise was 6 ng or 60 ng.ml^?1 for 100 μl samples. In-line trace enrichment was used to decrease detection limits and linear calibration curves were observed in the ranges studied; 0.5 to 50 ng.mL^?1 for ground waters and 25 to 400 ng.mL^?1 for artificial urine.     

Comparative Study of Water Softening with Granular and Fibrous Ion Exchangers

Comparative study of softening of model hard water with both strongly acidic fibrous FIBAN K-1 and granular KU-2 ion exchangers was carried out. The influence of the filter-bed height, packing density of fibrous ion exchangers, volume sorption capacity, and filtering rate on the efficiency of calcium removal from model hard water was analyzed.     

Synthesis,Ion Exchange Properties and Applications of Thermally Stable Stannic Selenophosphate: Comparison With Other TIN(IV) Based Ion Exchangers

Abstract

Samples of stannic selenophospnate have been synthesized by mixing 0.05m aquous solutions of stannic chloride, sodium selenite and sodium dihydrogen phosphate in different volume ratios at pH = 1. The chemical compositions have been determined. The Tin, Selenium and Phosphorous contents of all these samples have been found to be in the ratio of 1:1:1. Sample with a high ion exchange capacity (1.63 meq/ dry gm) has been studied in detail. pH titrations, IR and X-ray analysis, distribution coefficients of metal ions in different systems were performed. The differential selectivity of metal ions on stannic selenophosphate has been utilized for the important separations. Fourteen quantitative separations of industrial and analytical-importance have been achieved on its column. A comparison of the important properties of stannic selenophosphate have been made with stannic tungsto-arsenate, stannic molybdoarsenate, stannic arsenophosphate, stannic vanadophosphate, stannic phosphate and stannic selenite. It peak due to inter stitial water (1600cm^?1) persists upto 500°C. However, the peak vanishes completely when the drying temperature is increased to 800°C.     

Suspension Fertilizers Based on Waste Phosphates from the Production of Polyols

Phosphorus raw materials are non-renewable, and their resources are shrinking faster and faster as a result of increased fertilizer production. This is due to the increasing population and the need to produce more food. Phosphorus, on the other hand, is one of the main nutrients of plants, without which it is impossible to conduct intensive agricultural production. There are no economically significant phosphate resources in Europe, so they must be imported. That is why it is so important to reduce losses and recover this element from waste streams, which was reflected in the new EU Regulation 2019/1009. A prospective option is to use waste phosphates from the production of polyether polyols. Previous studies show that they contain about 20% phosphorus. Due to their high water content, the most advantageous form of their application is the production of fertilizers in the form of a suspension. The aim of the study is to assess the possibility of using waste phosphates from the production of polyols as raw materials for the production of suspension fertilizers.     

Sorption of Nickel Ions from Aqueous Solutions by Ion Exchangers

Sorption of Ni²⁺ions from aqueous solutions by ion exchangers differed in their chemical nature and structure was studied. Based on the endothermic curves of ice melting obtained by a differential scanning calorimetry, the amounts of freezing and non-freezing water present in free volumes (pores) of the studied ion exchangers were calculated. Comparison of results obtained from the kinetic curves of nickel ion sorption with data on differential scanning calorimetry indicates a role of structural factor in the sorption of nickel ions. It was found that, depending on the total amount of freezing and non-freezing water, the KU-2-8 sulfonated cationite is the most preferable ion exchanger for the sorption of nickel ions from aqueous solutions. Therefore, sorbent efficiency in this case is determined by its structure rather than by chemical nature.     

Convenient Synthesis of Polyfunctional Diphosphonium Salts Based on 2-Methyl-1,4-naphthoquinone

Russian Journal of Organic Chemistry - An efficient procedure has been proposed for the synthesis of new 1,4-dioxo- and 1,4-dihydroxynaphthyl-substituted diphosphonium salts from...     

Synthesis of a Novel Polyfunctional Anionic Macroinitiator from a Polyfunctional 1,1‐Diphenylethylene Agent

Summary: A polyfunctional 1,1‐diphenylethylene (DPE) agent was prepared by ring‐opening metathesis polymerization of a DPE‐functionalized norbornene monomer. Its reaction with sec‐butyllithium gave a novel polyfunctional anionic macroinitiator with one 1,1‐diarylalkyllithium initiation functionality per repeating unit. The significant applicability of this polyfunctional anionic macroinitiator was demonstrated by its excellent initiation efficiencies in anionic polymerization and a preparation of a graft copolymer with well‐controlled long and dense diblock grafts.

Preparation of a polyfunctional anionic macroinitiator based on ROMP and DPE chemistry.     

Acid-Base Properties and Structural Features of Composite Ion Exchangers Based on KU-23 and KM-2p Cation Exchangers and Hydrated Zirconium Oxide

A method for introduction of hydrated zirconium oxide into macroporous cation exchangers KU-23 and KM-2p and the acid-base properties and structural features of the composite ion exchangers are described.     

Organic Ion Exchangers. Synthesis and Their Behaviour in the Retention of Some Metal Ions

Summary: Three pyridine strong base anion exchangers as beads were obtained by quaternization reactions of a 4-vinylpyridine : 8% divinylbenzene copolymer of gel type. These resins possess methyl / ethyl / butyl radicals as substituents on N⁺ atoms and have exchange capacities of 4.80 mEq/g and 2.10 mEq/mL. For pyridine strong base anion exchangers, the behaviours in the retention processes of Cr(VI) as oxyanions and Ga(III) as [GaCl₄]⁻ complex anion were evaluated with the bath method. All the resins exhibited retention properties, but the retained amounts of the metal cations are different as a function of the alkyl length as substituent on N⁺ atoms and the complex anion nature. Thus, Cr(VI) oxyanions are best retained by the resin with  CH₃ as substituent on N⁺ atoms while [GaCl₄]⁻ complex anion by the resin with  C₄H₉ as substituent on N⁺ atoms. By aminolysis reaction of an ethylacrylate : acrylonitrile : divinylbenzene copolymer as beads of macroporous type with NH₂OH · HCl in the presence of C₂H₅OH a new chelating ion exchanger was performed which contains both amidoxime and hydroxamic acid functional groups. This ion exchanger has the retention property for different metal cations but its retention capacities values are strongly dependent of the nature of metal cation and the counterion as well as pH of the solution. Thus, in the static conditions Zn(II) cation with NOequation/tex2gif-stack-1.gif anion as counterion is retained with the best result at pH = 5. As an example, for the aqueous metal cation solution of 10⁻² M concentration for Zn(NO₃)₂ the resin possess at equilibrium a retention capacity of 6.70 mmol Zn/g dry resin and for Cu(II) from Cu(NO₃)₂ solution of same concentration, the retention capacity is 0.22 mmol Cu/g dry resin and Fe(III) from Fe(NO₃)₃ solution is not retained.     

Sorption of Some Metal Ions on Inorganic Electron and Ion Exchangers Based on Zirconium(IV)

Conditions of sorption of nonferrous metal ions on inorganic electron and ion exchangers based on zirconium(IV) were analyzed. The sorption capacity was evaluated as influenced by pH, concentration, and temperature of the contacting solutions and nature and chemical composition of the ion exchanger.     

Synthesis of Sulfur-Containing Polyfunctional Terpenoids from (-)-Carvone

Reactions of (-)-carvone with aliphatic, aromatic, heterocyclic, and functional thiols, catalyzed with potassium carbonate, gave the corresponding derivatives in high yields. Isopropyl mercaptan, 2-mercaptoethanol, furfuryl mercaptan, and N-acetylcysteine add across the endocyclic double bond of (-)-carvone with the predominant formation of the isomers with the S configuration of C³, whereas addition of hexadecyl mercaptan and 1,2-ethanedithiol mainly yields the R isomers.     

Sorption Behaviour of Molybdenum on Different Antimonates Ion Exchangers

Various antimonate compounds are well known as important inorganic ion exchangers, since they resist radiation and chemical degradation and also exhibit selectivities towards different cations. Ceric, silicon, titanium and ferric antimonates were prepared as inorganic ion exchangers. Characterization of these materials has been described using different techniques, including thermal analysis, surface area measurements, X-ray diffraction and IR-spectroscopy. In batch distribution experiments the influence of HNO₃ molarity and Mo concentration for Mo sorption on different matrices is described in terms of their retention capacities and distribution coefficients.The selectivities of these exchangers towards molybdenum are in the order: CeSb > SiSb > FeSb > TiSb.     

Mobility of Ni(II) Ions in Inorganic Ion Exchangers Based on Zirconium Hydroxophosphate

The mobility of Ni(II) ions in inorganic ion exchangers based on zirconium hydroxophosphate with varying phosphorus content was studied using electromigration and kinetic methods. It was found that the effective diffusion coefficient of nickel in the ion exchanger phase increased with increasing phosphorus content within the range 1·10^–13 to 2·10^–12 m²/s.     

Synthesis and Physicochemical Study of New Surfactants Derived from Carboxylic Acid Sugars

Surfactants based on sugars are important for a variety of applications, and for this reason we present the synthesis of new sugar carboxylate/amine salts. These surfactants were obtained via a simple synthesis in high yields. Their interfacial properties were measured and the results of these tests are presented and analyzed to provide suggestions for how these surfactants might be used. Some of these surfactants demonstrated water solubility over a wide temperature range, ability to form stable foams or emulsions, and stability in the presence of calcium salts.     

Synthesis and Physicochemical Study of Chitosan-Containing Calcium Hydroxylapatites

The CaCl₂-(NH₄)₂HPO₄-(C₆H₁₁NO₄)_n-NH₃-H₂O system at 25°C was studied by the solubility (Tananaev’s residual concentrations) technique and pH measurements. The parameters providing for the coprecipitation of nanocrystalline (12.5–18.7 nm) calcium and chitosan hydroxylapatites were found. Calcium-deficient chitosan hydroxylapatites Ca_9.8(PO₄)₆(OH)_1.6 · xC₆H₁₁NO₄ · yH₂O, where x = 0.075 or 0.37 and y = 5.8 or 6.2, and stoichiometric calcium hydroxylapatites Ca₁₀(PO₄)₆(OH)₂ · xC₆H₁₁NO₄ · yH₂O, where x = 0.075, 0.1, 0.2, 0.37, 0.5, or 0.75 and y = 5.7–7.5, were synthesized. Solid phases were characterized by chemical analysis, X-ray powder diffraction, thermogravimetric analysis, and IR spectroscopy.     

Synthesis of Polyfunctional Terpenoids from Monoterpenes and N-(2-Mercaptopropyonyl)glycine

Addition of N-(2-mercaptopropyonyl)glycine to (+)-limonene or (-)--pinene in the presence of a Lewis acid involves the mercapto group; simultaneously, the carboxyl function is esterified by ethanol used as solvent. Both reactions give rise to a terpenoid of the menthane structure, which contains, along with a sulfide group, a peptide fragment promising in terms of biologic activity, as well as an ester group.