Ammonium properties

In general, the first step in virtual screening is the filtering by the application of Lipinski s Rule of Five [20]. Lipinski s work was based on the results of profiling the calculated physical property data in a set of 2245 compounds chosen from the World Drug Index. Polymers, peptides, quaternary ammonium, and phosphates were removed from this data set. Statistical analysis of this data set showed that approximately 90% of the remaining compounds had ... 

The 2-imino-4-thiazolines may be used as ultraviolet-light stabilizers of polyolefin compositions (1026). 2-Aminothiazole improves adhesive properties of wood to wood glue (271). Cbmpound 428 exhibits antioxidant properties (Scheme 242) (1027). Ammonium N-(2-thiazolyl)dithio-carbamate (429) is a bactericide and fungicide used in industrial products such as lumber, paint, plastics, and textiles (1037). Compound 430 is reported (1038) to form an excellent volume of foam coating in aluminum pans when ignited with propane. 

In the introduction we noted that both Berzelius and Wohler were fascinated by the fact that two different compounds with different properties ammonium cyanate and urea pos sessed exactly the same molecular formula CH4N2O Berzelius had studied examples of similar phenomena earlier and invented the word isomer to describe different compounds that have the same molecular formula... 

This property of quaternary ammonium salts is used to advantage m an experi mental technique known as phase transfer catalysis Imagine that you wish to carry out the reaction... 

Urea can be considered the amide of carbamic acid, NH2COOH, or the diamide of carbonic acid, CO(OH)2. At room temperature, urea is colorless, odorless, and tasteless. Properties are shown ia Tables 1—4. Dissolved ia water, it hydrolyzes very slowly to ammonium carbamate (1) and eventually decomposes to ammonia and carbon dioxide (qv). This reaction is the basis for the use of urea as fertilizer (qv). 

Amidation. Heating of the diammonium salt or reaction of the dimethyl ester with concentrated ammonium hydroxide gives adipamide [628-94-4] mp 228°C, which is relatively insoluble in cold water. Substituted amides are readily formed when amines are used. The most industrially significant reaction of adipic acid is its reaction with diamines, specifically 1,6-hexanediamine. A water-soluble polymeric salt is formed initially upon mixing solutions of the two materials then hea ting with removal of water produces the polyamide, nylon-6,6. This reaction has been studied extensively, and the hterature contains hundreds of references to it and to polyamide product properties (31). 

Ammonium nitrate-based explosives account for about 97% of total U.S. industrial explosive consumption. Coal mining in the United States formed about 65—68% of the demand for explosives in 1991. The remaining uses were quarrying and nonmetal mining, 15% metal mining, 10% constmction, 7% miscellaneous uses, 3—4%. The properties of ammonium nitrate are given in Table 18 (173,239—242). 

S. R. Brinkley and W. E. Gordon, "Explosive Properties of the Ammonium Nitrate-Fuel Oil System," in Proceedings of 31st Inst. Congress of Industrial Chemisty, Liege, Belg., 1958. 

Oxidizers. The characteristics of the oxidizer affect the baUistic and mechanical properties of a composite propellant as well as the processibihty. Oxidizers are selected to provide the best combination of available oxygen, high density, low heat of formation, and maximum gas volume in reaction with binders. Increases in oxidizer content increase the density, the adiabatic flame temperature, and the specific impulse of a propellant up to a maximum. The most commonly used inorganic oxidizer in both composite and nitroceUulose-based rocket propellant is ammonium perchlorate. The primary combustion products of an ammonium perchlorate propellant and a polymeric binder containing C, H, and O are CO2, H2, O2, and HCl. Ammonium nitrate has been used in slow burning propellants, and where a smokeless exhaust is requited. Nitramines such as RDX and HMX have also been used where maximum energy is essential. 

L. Asaoka, Phase Stabili d Ammonium Nitrate Effects on Minimum Signature Propellant Properties, Vol. 5, 3 CPIA Pubhcation 550, Anaheim, Calif., 1990. 

Table 4. Properties of Urea Ammonium Nitrate Nonpressure Solutions...

Molybdenum Oxides. Molybdenum was one of the first elements used to retard the flames of ceUulosics (2). Mote recently it has been used to impart flame resistance and smoke suppression to plastics (26). Molybdic oxide, ammonium octamolybdate, and zinc molybdate ate the most widely used molybdenum flame retardants. Properties ate given in Table 5. These materials ate recommended almost exclusively for poly(vinyl chloride), its alloys, and unsaturated polyesters (qv). 

Phosphorylated cottons are flame resistant ia the form of the free acid or the ammonium salt. Siace these fabrics have ion-exchange properties, conversion to the sodium salt takes place readily during laundering if basic tap water is used. However, flame resistance can be restored if the fabric is treated with either acetic acid [1563-80-8] or ammonium hydroxide [1336-21 -6] after washing. 

Phosphonomethylated Ethers. A phosphoms-containing ether of ceUulose can be prepared by the reaction of cotton ceUulose with chioromethylphosphonic acid [2565-58-4] ia the presence of sodium hydroxide [1310-73-2] by the pad-dry-cure technique (62). Phosphoms contents of between 0.2 and 4.0% are obtained. This finish is durable but has high ion-exchange properties and is flame resistant only as the ammonium salt. DurabUity on medium weight fabrics is obtained with chi oromethylph osph onic diamide. This finish has never penetrated the flame retardant market (63). 

Anhydrous aluminum triduotide, A1F., is a white crystalline soHd. Physical properties are Hsted ia Table 2. Aluminum duotide is spatingly soluble ia water (0.4%) and iasoluble ia dilute mineral acids as well as organic acids at ambient temperatures, but when heated with concentrated sulfuric acid, HF is hberated, and with strong alkah solutions, aluminates are formed. A1F. is slowly attacked by fused alkahes with the formation of soluble metal duotides and aluminate. A series of double salts with the duotides of many metals and with ammonium ion can be made by precipitation or by soHd-state reactions. 

Properties. Ammonium bifluoride, NH4HF2, is a colorless, orthorhombic crystal (2). The compound is odorless however, less than 1% excess HF can cause an acid odor. The salt has no tendency to form hydrates yet is hygroscopic if the ambient humidity is over 50%. A number of chemical and physical properties are Hsted in Table 1. 

Properties. A suimnaiy of the chemical and physical properties of alkah-metal and ammonium fLuoroborates is given in Tables 2 and 3. Chemically these compounds differ from the transition-metal fLuoroborates usually separating in anhydrous form. This group is very soluble in water, except for the K, Rb, and Cs salts which ate only slighdy soluble. Many of the soluble salts crystallize as hydrates. 

The most widely used alkyl sulfate in shampoo preparation is lauryl sulfate. The alkyl component of this sulfate ranges from C-10 to C-18 with a predominance of the C-12 (lauryl) component. By distillation of the fatty alcohol, certain cuts can be obtained which offer the best effects in foaming, cleansing, and rinsing properties for the alkyl sulfate preparation. The range which appears to be most desirable is between C-12 and C-16. Lauryl sulfate detergents are available in various salt forms with the sodium, ammonium, and triethanolamine types being used most frequently in shampoos. 

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