Borax complex

Key words Poly(vinyl alcohol) -borax complex - dynamic hght scattering - dynamic viscoelasticity -transient network... 

Xylitol reacted with boric acid under reduced pressure to give mixtures of boric esters and polymeric xylitol-borate complexes, and a cryoscopic study of the borate complexes formed by pentaerythritol has been reported. N.m.r. spectroscopic studies have confirmed that borax complexes with HO-1 and -2 and with HO-3, -5, and -6 of D-glucose in the a-furanose form to give bidentate and terdentate complexes, respectively. Only those D-glucobioses that are (1 3)- or (1 6)-linked formed complexes with borax. 

Tetraalkyl titanates react with organic borates, B(OR )2, to give complexes of the general formula Ti(OR)4 B(OR )2, which are useful as catalysts and cross-linking agents (562). Mixtures of chelated organic titanates such as TYZOR TE and TYZOR LA with alkaU metal borates, such as borax, or boric acid can be used to produce shear-stable fracturing fluids (563). 

At Seades Lake, sodium sulfate is recovered as one of three coproducts in a senes of complex operations where soda ash and borax are also recovered from the brine. Anhydrous sodium sulfate is recovered by artificially evaporating the water from Glauber s salt. 

The diazotization of amino derivatives of six-membered heteroaromatic ring systems, particularly that of aminopyridines and aminopyridine oxides, was studied in detail by Kalatzis and coworkers. Diazotization of 3-aminopyridine and its derivatives is similar to that of aromatic amines because of the formation of rather stable diazonium ions. 2- and 4-aminopyridines were considered to resist diazotization or to form mainly the corresponding hydroxy compounds. However, Kalatzis (1967 a) showed that true diazotization of these compounds proceeds in a similar way to that of the aromatic amines in 0,5-4.0 m hydrochloric, sulfuric, or perchloric acid, by mixing the solutions with aqueous sodium nitrite at 0 °C. However, the rapidly formed diazonium ion is hydrolyzed very easily within a few minutes (hydroxy-de-diazonia-tion). The diazonium ion must be used immediately after formation, e. g., for a diazo coupling reaction, or must be stabilized as the diazoate by prompt neutralization (after 45 s) to pH 10-11 with sodium hydroxide-borax buffer. All isomeric aminopyridine-1-oxides can be diazotized in the usual way (Kalatzis and Mastrokalos, 1977). The diazotization of 5-aminopyrimidines results in a complex ring opening and conversion into other heterocyclic systems (see Nemeryuk et al., 1985). 

B-C bonds, 3, 97 B-N bonds, 3, 97 B-O bonds, 3,94 B-P bonds, 3, 97 B-Si bonds, 3, 97 oxo acid anion complexes, 3, 96 Borates, alkoxo-, 3, 94 Borates, amidotrihydro-, 3,92 Borates, aryloxo-, 3, 94 Borates, carboxylato-, 3,96 Borates, catechol, 3,95 Borates, chlorosulfato-, 3,97 Borates, dicarboxylato-, 3,96 Borates, dipyrazol-l-yl-, 3, 92 Borates, halogeno-, 3,92 Borates, halogenohydro-, 3,90 Borates, hydro-, 3,90 Borates, hydrohydroxo-, 3,90 Borates, hydropyrazol-l-yl-, 3, 92 Borates, hydroxo-, 3,94 Borates, hydroxycarboxylato-, 3,96 Borates, inositol, 3, 95 Borates, monoalkyl-, 3, 92 Borates, monophosphido-, 3, 92 Borates, peroxohydroxo-, 3, 94 Borates, polyol, 3, 95 Borates, pyrrol-l-yl-, 3, 92 Borates, sulfato-, 3, 97 Borates, tetrabromo-, 3, 92 Borates, tetrachloro-, 3, 92 Borates, tetrafluoro-, 3, 92 minerals, 6, 847 Borates, tetrahalogeno-mixed, 3, 93 nB NMR, 3, 92 Borates, tetraiodo-, 3, 92 Borates, tetranitrato-, 3, 96 Borates, tetraperchlorato-, 3, 97 Borates, tripyrazol-l-yl-, 3, 92 Borax, 3,101 Borazines... 

Interference with absorption when isoniazid is co-administered with borax, plaster, magnet or metal complex, further absorption is prevented. 

Numerous CE separations have been published for synthetic colours, sweeteners and preservatives (Frazier et al., 2000a Sadecka and Polonsky, 2000 Frazier et al., 2000b). A rapid CZE separation with diode array detection for six common synthetic food dyes in beverages, jellies and symps was described by Perez-Urquiza and Beltran (2000). Kuo et al. (1998) separated eight colours within 10 minutes using a pH 9.5 borax-NaOH buffer containing 5 mM /3-cyclodextrin. This latter method was suitable for separation of synthetic food colours in ice-cream bars and fmit soda drinks with very limited sample preparation. However the procedure was not validated for quantitative analysis. A review of natural colours and pigments analysis was made by Watanabe and Terabe (2000). Da Costa et al. (2000) reviewed the analysis of anthocyanin colours by CE and HPLC but concluded that the latter technique is more robust and applicable to complex sample types. Caramel type IV in soft drinks was identified and quantified by CE (Royle et al., 1998). 

Complex hydrides react with water to give hydrogen, a metal hydroxide and borax [90]. Very high hydrogen densities are reached if the water from the combustion of the hydrogen is reused (Table 5.7). 

The optical activity of the hexitols is of a low order. It may be enhanced by the addition of various complex-forming salts, borax and ammonium molybdate being the ones most used. Since the amount of enhancement is a function of the relative proportions of polyol and booster, it is regrettable that definite amounts of borax or molybdate have not always been reported in the past. 

The B2O3 content of borax may be determined by extraction into HCl solution followed by complexation with mannitol and titration with dUute NaOH. The Na20 content of horax may he measured by titration of an aqueous solution with dUute HCl. Boron and sodium metals in the acid extract of horax may be analyzed by atomic absorption or emission spectroscopy after appropriate dUution of the extract. In the solid phase B2O3 and Na20 may he measured nondestructively by x-ray techniques. 

Boron trifluoride is prepared by treating borax with hydrofluoric acid or boric acid with ammonium bifluoride. The complex intermediate product is then treated with cold fuming sulfuric acid. 

The optical rotation of aqueous solutions will increase to + 4.0 to +7.0° by the addition of complexing salts, such as borax or ammonium molybdate. 

The chemistry of boron is exceedingly complex and rivals that of carbon in its diversity. Most boron compounds, however, enter or degrade in the environment to borates (B-0 compounds), such as borax and boric acid, and these are considered to be the most significant ecologically. 

A vanadium borate of uncertain composition is obtained by fusing a mixture of vanadium pentoxidc and boric anhydride. It forms green or yellowish-green crystals which, however, undergo hydrolysis readily.2 A vanadyl borate is also obtained by the action of borax on vanadyl sulphate solution,3 and a complex vanadium borotungstate has been prepared. 

Most of the work on the boric acid-diol reaction during the last twenty years has been done to determine the coordination number of the diol (number of diol molecules) in the complex and to evaluate the equilibrium constant (often called a stability constant) for a number of diol-boric acid reactions. Several techniques have been used to study these questions, including polarimetry (7), optical rotatory dispersion (8), polarography (9), conductivity (3), vapor pressure osmometry (10), and electrochemistry (II, 12, 13). The most frequently studied system has been the electrochemical (pH) titration of boric acid or borax solutions with various diols. 

We also made a few measurements as a function of ionic strength at pH = 3 and 13. The results at pH = 13 gave log k = 1.33 0.01 min 1 M-1 for four measurements between I = 0 to 3m. At a pH = 3 in dilute solutions below 0.04M, no ionic strength dependence was found however, at I = 3.0m, the rate was ten times faster that at I = 0. We attribute this increase in rate to the presence of trace metals. All of our runs at pH = 8 to 13 were made with enough borax to complex these trace metals and suppress the catalytic effect. An experiment at pH = 11 without borax was completed within 5 minutes compared to 1.5 hours with 0.01 M borax. These results support our contention that the effect of ionic strength on the rates of oxidation are independent of pH if the catalytic effects of trace impurities are avoided. 

An additional example for ion pair extraction of QTA (ipratropium) was described by Tang et al. mixing equine urine with alkaline saturated borax buffer prior to extraction with EE allowing to remove more lipophilic compounds. Subsequently, the EE layer was discarded and an alkaline potassium iodide-glycine solution was added to the aqueous phase. Afterwards, the ipratropium-ion pair complex was extracted twice with dichloromethane yielding in a recovery of 82 % [24] (Table 3). 

Boron is present in the earth s crust at a level of only three parts per million, but there are areas where it is concentrated as borate salts (salts of the oxidized form of elemental boron) in substantial volumes for mining. The United States and Turkey supply 90% of the global borate demand. Rio Tinto Minerals (RTM)/U.S. Borax, the largest borate producer, operates an open pit mine and refinery complex in the Mojave desert of California. The principal minerals in the deposit are tincal and kernite (Table 9.1). 

Wool Wool, though not as flammable as cotton, still needs flame retardation for specific applications, e.g., carpets, upholstered furniture in transport, etc. Ammonium phosphates and polyphosphate, boric acid-borax, and ammonium bromide can be successfully used in nondurable FR finishes for wool. Various commercial products have been reviewed by Horrocks.3 The most successful durable treatment for wool is Zirpro, developed by Benisek, which involves exhaustion of negatively charged complexes of zirconium or titanium onto positively charged wool fibers under acidic conditions at 60°C. The treatment can be applied to wool at any processing stage from loose fiber to fabric using exhaustion techniques. 

Under alkaline conditions, boric acid (or at this pH, boron tetrahydrate) forms complexes with diols 11) The formation of such a complex between two polysaccharide molecules can lead to crosslinking. The use of borax can, therefore, be expected to increase the stability of the bonds between the hemicellulose and between the hemicellulose and cellulose fibers in the paper. 

The effect of borax on the strength of the hemicellulose adhesive was subsequently investigated. A factorial experiment was done employing five concentrations of borax and five concentrations of sodium hydroxide. The sodium hydroxide variable was included, since formation of the diol-boron complex is pH sensitive 12). 

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