Partial phosphates

In the preparation of surfactants by the reaction of alcohols with P4Ol0 with subsequent neutralization of the partial phosphate esters with a base, the quality of the surfactants is improved by using RNEt3OH (R = Et or benzyl) in alcoholic solution as the base, by using C6 10 alcohol mixtures of hydroxyethylated C7 9 alcohols or equimolar mixtures of C6 I0 alcohols with polyethylene glycol (mol wt 200-1500) and by using a reaction temperature of 55-60°C [8]. 

Silica gel with a large surface area is used for catalysis and column chromatography. Silica gel is also used as a partial phosphate replacement in soaps and detergents. 

The second option was that only partial degradation of the complex took place prior to bone uptake, or only partial phosphate coordination takes place in bone mineral. The partial coordination leads to considerable variability in coordination structure and observation of a wide range of P coupling constants in the ESEEM/HYSCORE spectra. Such an explanation was offered by Fukui et al. to explain the broad, unresolved signals below 8 MHz that were thought to be due to diversity in phosphate coordination mode [71]. 

This method utilizes pH, chelate formation, oxidation-reduction reaction, or light to deform polymers isothermally and reversibly (see Fig. 5). Unlike the methods described thus far, the main characteristic of this method is reversible shape changes. For example, poly(acrylic acid) fibers that have the shape memory property with changes in pH possess dissociated charges. These charges repel each other and the polymer chains are stretched. On the other hand, in a low pH range, there are no charges and the polymer chains shrink. Another example is partially phosphated poly(vinyl alcohol) film, which responds to chelate formation. If Cu " is included, the film shrinks by formation of crosslinks. 

Recently, it has been demonstrated that helix bending can be induced by partial phosphate neutralization. In line with the early suggestions of Mirzabekov and Rich, Strauss and Maher have shown that neutralizing the phosphate groups on one face of the DNA helix leads to unbalanced electrostatic repulsions between the remaining anionic phosphates... 

Chew. Descrip. Partial phosphate ester Ionic Nature Anionic... 

Corrosion inhibitors partial esters of succinic acid, fatty acids, sulfonates, phenates, amine phosphates. 

The steel container partially Tilled with phosphate glass... 

Solvating extractants contain one or more electron donor atoms, usually oxygen, which can supplant or partially supplant the water which is attached to the metal ions. Perhaps the best known example of such an extractant is tri-( -butyl) phosphate) [126-73-8] (TBP), which forms... 

In the 1960—1980 period, the use of more economical synthetic isopropyl- and /-butylphenols as alternatives to cresols was developed (98,99). Commercial triaryl phosphates such as FMC s Kronitex 100 and Ak2o s Phosflex 31P and 41B are based on partially isopropylated or /-butylated phenol. The relative volatihties and oxidative stabiUties of these phosphates have been compared the /-butylphenyl phosphates are the most oxidatively stable of the alkylphenyl phosphates (100). 

The ores of most importance are fluorspar, CaF2 fluorapatite, Ca (P0 2Fj cryoHte [15096-52-3], Na AlF. Fluorspar is the primary commercial source of fluoiine. Twenty-six percent of the world s high quaHty deposits of fluorspar are ia North America. Most of that is ia Mexico. United States production ia 1987—1991 was 314,500 metric tons, most of which occurred ia the Illinois-Kentucky area. Imported fluorspar ia 1990—1991 represented about 82% of U.S. consumption 31% of U.S. fluorspar imports were from Mexico and 29% from China compared to 66% from Mexico ia the 1973—1978 period. The majority of the fluorine ia the earth s cmst is ia phosphate rock ia the form of fluorapatite which has an average fluorine concentration of 3.5%. Recovery of these fluorine values as by-product fluorosiHcic acid from phosphate production has grown steadily, partially because of environmental requirements (see Phosphoric acid and THE phosphates). 

The majority of the fluorine ia the earth s cmst is present in the form of the phosphoms fluoride fluoroapatite [1306-05 ] Ca (P0 2F- Phosphate rock deposits contain an average concentration of 3.5 wt % fluorine. During phosphate processing these fluorine values are partially recovered as by-product fluorosihcic acid. The amount of fluorosiUcic acid recovered has grown steadily, in part because of environmental requirements (see Phosphoric acid and THE phosphates). 

Garbodiimide Formation. Carbodiimide formation has commercial significance in the manufacture of Hquid MDI. Heating of MDI in the presence of catalytic amounts of phosphine oxides or alkyl phosphates leads to partial conversion of isocyanate into carbodiimide (95). The carbodiimide (39) species reacts with excess isocyanate to form a 2 + 2cycloaddition product. The presence of this product in MDI leads to a melting point depression and thus a mixture which is Hquid at room temperature. 

Orthophosphate salts are generally prepared by the partial or total neutralization of orthophosphoric acid. Phase equiUbrium diagrams are particularly usehil in identifying conditions for the preparation of particular phosphate salts. The solution properties of orthophosphate salts of monovalent cations are distincdy different from those of the polyvalent cations, the latter exhibiting incongment solubiUty in most cases. The commercial phosphates include alkah metal, alkaline-earth, heavy metal, mixed metal, and ammonium salts of phosphoric acid. Sodium phosphates are the most important, followed by calcium, ammonium, and potassium salts. 

Ammonium Phosphates. In the manufacture of ammonium phosphates, an atmosphere of ammonia may need to be maintained because the partial pressure of ammonia rises rapidly as either the temperature or the NH2/P20 mole ratio of the reaction mass increases. Phosphoric acid reacts quickly with ammonia vapor and is used in multistage reactor systems as a scmbber fluid to prevent NH emissions and recover ammonia values. For example, H PO scmbbing of coke-oven off-gases produces ammonium phosphates of relatively good purity. 

The need for acid concentrators exists because many uses of sulfuric acid do not lead to its consumption. Instead, the acid is diluted and partially degraded and contaminated. In the past, large amounts of acid were disposed of either by usiag it ia the phosphate fertilizer iadustry to dissolve phosphate rock or by neutralization and subsequent discharge to waterways. 

Plasticized PVC. Chlorinated paraffins are employed as secondary plasticizers with fire-retardant properties in PVC and can be used as partial replacements for primary plasticizers (qv) such as phthalates (1) and phosphate esters (2). 

Zinc Phosphate Cements. Zinc phosphate cements are the oldest of the aqueous-based cements (see Table 1) and are stiU used in a wide range of appHcations eg, cavity bases, temporary restoratives, and for the fixation of inlays, crowns, fixed partial dentures (bridges), posts, facings, and orthodontic bands. 

The paper-impregnation drying oven exhausts contain high concentrations (10—20% LEL) of alcohols and some resin monomer. Vinyl resins and melamine resins, which sometimes also contain organic phosphate fire retardants, may be used for air filters. The organic phosphates could shorten catalyst life depending on the mechanism of reduction of catalyst activity. Mild acid leaching removes iron and phosphoms from partially deactivated catalyst and has restored activity in at least one known case. 

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