Uses and Properties

Silver is very ductile and malleable, almost as much as gold. It does not react with water and air at ordinary temperatures. Silver is resistant to aUcaHs and most adds. In contrast to gold, however, it is dissolved by nitric acid. Sulfur and sulfides tarnish silver owing to the formation of black silver sulfide. Contact between silver objects and eggs must be avoided as they contain much sulfur in their protein. 

In the year 2000 the consumption of silver in the world was 25 000 tonnes, 18 300 tonnes produced from mining, the rest from recycling processes including quantities sold by government monetary authorities. The silver was mainly used within three areas of about the same size Silverware/jewelry, photography, and different industrial applications, including electronics. 

In a strong period for silver between 1979 and 1988 the price reached a high of 49.45 per ounce in 1980. By the end of the 20 century, silver had lost much of its image as a precious metal and become more of an industrial metal. The price is nowadays fairly stable, averaging around 5.00 per ounce. 

Poly(vinyl acetate) is too soft and shows excessive cold flow for use in moulded plastics. This is no doubt associated with the fact that the glass transition temperature of 28°C is little above the usual ambient temperatures and in fact in many places at various times the glass temperature may be the lower. It has a density of 1.19 g/cm and a refractive index of 1.47. Commercial polymers are atactic and, since they do not crystallise, transparent (if free from emulsifier). They are successfully used in emulsion paints, as adhesives for textiles, paper and wood, as a sizing material and as a permanent starch . A number of grades are supplied by manufacturers which differ in molecular weight and in the nature of comonomers (e.g. vinyl maleate) which are commonly used (see Section 14.4.4) 

The polymers are usually supplied as emulsions which also differ in the particle size, the sign of the charge on the particle, the pH of the aqueous phase and in other details. 

Being an amorphous polymer with a solubility parameter of 19.4 MPa , it dissolves in solvents with similar solubility parameters (e.g. benzene 8 = 18.8 MPa, chloroform 8 = 19.0 MPa, and acetone 8 = 20.4 MPa.  

Vinyl alcohol does not exist in the free state and all attempts to prepare it have led instead to the production of its tautomer, acetaldehyde. 

The term hydrolysis is sometimes incorrectly used to describe this process. In fact water does not react readily to yield poly(vinyl alcohol)s and may actually retard reaction where certain catalysts cire used. 

Cadmium pigments are mainly used to color plastics. They have brilliant, pure shades (yellow, orange, red, and bordeaux), good hiding power, and moderate tinting strength. 

A very useful feature of plastics colored with cadmium pigments is the dimensional stability of injection-molded parts with a large surface area. The combination of these properties is not matched by any other class of colorant. 

A further use of cadmium pigments is in paints and coatings (powder paints, silicone resins, and automotive topcoats) but this is declining. 

Cadmium pigments, especially cadmium red, are very sensitive to intensive grinding, which causes loss of brilliance due to an increase in the number of irregular lattice defects. A brilliant red shade may become a dirty brownish red. 

The cadmium pigments are lightfast but, like all sulfide pigments, are slowly oxidized to soluble sulfates by UV light, air, and water. This photooxidation is more pronounced with cadmium yellow than with cadmium red and can still be detected in the powder pigment which normally contains 0.1 % moisture. 

Potato protein dry matter content should be —90% in order to produce a balance between microbiological deterioration, energy consumption and fine powder content. The protein content of the dry matter is —85% and the bulk density is —550kg/m3. Potato protein contains a high amount of protein, as compared to fishmeal, milk powder and soy protein. Also, the amount of important amino acids, such as lysine, methionine and cystine, is relatively high. Potato protein is mainly sold as cattle feed. 

Native potato starch, which is used in the food, paper and textile industries, is often not optimal for a particular application. Modifications are done to obtain the properties needed for specific uses.26 28 More than 500 modifications of potato starch are currently known. This chapter presents an overview of the major commercial modifications rather than a complete bibliography of all potato starch reactions. With a distinction based on the chemical character of the product, three groups can be distinguished. Some derivatives are made from starch by a combination of reactions. 

Substituted products of starch are the esters and ethers of starch which prevent the formation of ordered structures in a starch paste and retard retrogradation. 

Lead has a low melting point (326°C). It is a soft, malleable metal, i.e., it can be easily formed into a variety of shapes. It can form alloys with many other metals. Other important industrial products containing Pb include pipes, paints, solders, glass, pottery glazes, rubber, plastics, and insecticides. 

Polyurethane coatings have three main advantages high mechanical resistance, outstanding chemical resistance, and (in the case of aliphatic polyisocyanates) excellent lightfastness and weather resistance. The properties of the paint systems which harden at ambient temperature are unsurpassed. They can also be combined and formulated in a large number of ways. Specific properties can be optimally adjusted even for extreme conditions. 

Nitric acid is a colourless liquid at room temperature and atmospheric pressure. It is soluble in water in all proportions and there is a release of heat of solution upon dilution. This solubility has tended to shape the process methods for commercial nitric acid manufacture. It is a strong acid that almost completely ionizes when in dilute solution. It is also a powerful oxidizing agent with the ability to passivate some metals such as iron and aluminium. A compilation of many of the physical and chemical properties of nitric acid is presented in Table A.1 of Appendix A. Arguably the most important physical property of nitric acid is its azeotropic point, this influences the techniques associated with strong acid production. The constant-boiling mixture occurs at 121.9°C, for a concentration of 68.4%(wt) acid at atmospheric pressure. 

Nitric acid has enormously diverse applications in the chemical industry. It has commercial uses as a nitrating agent, oxidizing agent, 

Nitric acid has a number of other industrial applications. It is used for pickling stainless steels, steel refining, and in the manufacture of dyes, plastics and synthetic fibres. Most of the methods used for the recovery of uranium, such as ion exchange and solvent extraction, use nitric acid. A full breakdown of the uses and applications of nitric acid is included in Ref. G6. 

An important point is that for most uses concerned with chemical production, the acid must be concentrated above its azeotropic point to greater than 95%(wt). Conversely, the commercial manufacture of ammonium nitrate uses nitric acid below its azeotropic point in the range 50-65%(wt). If the stronger chemical grade is to be produced, additional process equipment appropriate to super-azeotropic distillation is required. 

There is a potential health hazard when handling, and operating with, nitric acid. Nitric acid is a corrosive liquid that penetrates and destroys the skin and internal tissues. Contact can cause severe burns. The acid is a potential hazard, the various nitrogen oxides present as product intermediates in the process are also toxic. An assessment of the health risk must be fundamental to the design of any process. Further consideration and recommendations for the operating health risk and environmental impact of the plant are presented in Section 5.4. 

---

J. G. Pritchard, Poly(VinylAlcohol) Basic Properties and Uses, Polymer Monographs, Vol. 4, Gordon Breach, New York, 1970. 

Preparation, Properties and Uses of Acrylic Polymers, CM-19, Rohm and Haas Co., Philadelphia, Pa. 

J. S. Sconce, Chlorine, Its Manufacture, Properties, and Uses, Reinhold Publishing Corp., New York, 1962. 

R. Robbins, The Preparation, Properties, and Uses of HMX, Rpt. RR-GC-149, Holston Defense Corp., Kingsport, Term., 1958. 

J. Savitt, "Some Properties and Uses of Nitroguanidine," paper no. 38 in Proceedings of Institutefor Chemie der Traub-und-Explosivestaffe, ICT, International Jahrsteig, Kadsuike, ERG, 1985. 

Preparation. The preparation, properties, and uses of tetraduoroethylene have been described (see Fluorine compounds, organic-polytethafluoroethylene). ... 

K. E. Eoley, Chemical Properties and Uses of the yinderson s Com Cob Products, Anderson s brochure, Maumee, Ohio, 1978. 

Organometallics Commercial Product Data, FMC Lithium Division, Gastonia, N.C. Butyllithium—Properties and Uses, Chemetad GmbH Lithium Division, Frankfurt, Germany t-Butyllithium in Heptane, FMC Lithium Division, Gastonia, N.C. 

Typical chemical stmctures and representative sources of different classes of synthetics are given in Table 6. Properties and uses of representative synthetics foUow in Table 7. In addition to considering thek physical properties, selection is needed of appropriate paints, seals, hoses, plastics, and electrical insulation to avoid problems with the pronounced solvency and plasticizing action of many of these synthetic oils. 

W. J. Hayes, Jr., and E. R. Laws, Jr., eds.. Handbook of Pesticide Toxicology, Academic Press, Inc., San Diego, Calif., 1990. Three volume set provides detailed toxicological profiles of more than 250 insecticides, herbicides, and fungicides each compound described by identity, properties, and uses toxicity to humans, laboratory animals, domestic animals, and wildlife includes comprehensive coverage of diagnosis, treatment, prevention of injury, effects on domestic animals, wildlife, and humans - ISjOOO references. 

K. K. Unger, Porous Silica Its Properties and Use as Support in Column Eiquid Chromatography, Elsevier Science Publishing Co., Inc., New York, 1979. 

I. E. Neimark and R. Y. Sbeinfain, Silica Gel Preparation, Properties and Uses, Nauk Dumka, Kiev, CIS, 1973. 

Sihcone properties and uses have been discussed extensively (59,321—324). 

Polyoxyethylene Esters. This series of surfactants consists of polyoxyethylene (polyethylene glycol) esters of fatty acids and aUphatic carboxyhc acids related to abietic acid (see Resins, natural). They differ markedly from mono- and diglycerides in properties and uses. 

Monoa.lka.nola.mine Condensates. Coco, lauric, oleic, and stearic monoethanolamides and monoisopropanolamides are the principal surfactants ia the monoalkano1 amide group (Table 24). Monoalkanolamides are generally water-iasoluble soHds that are easily solubilized by hydrophilic surfactants. Except for solubiUty and viscosity, properties and uses are similar to the diethanolamides. Manufacturing processes and yields have been described (96). 

Polyall lene Oxide Block Copolymers. The higher alkylene oxides derived from propjiene, butylene, styrene (qv), and cyclohexene react with active oxygens in a manner analogous to the reaction of ethylene oxide. Because the hydrophilic oxygen constitutes a smaller proportion of these molecules, the net effect is that the oxides, unlike ethylene oxide, are hydrophobic. The higher oxides are not used commercially as surfactant raw materials except for minor quantities that are employed as chain terminators in polyoxyethylene surfactants to lower the foaming tendency. The hydrophobic nature of propylene oxide units, —CH(CH2)CH20—, has been utilized in several ways in the manufacture of surfactants. Manufacture, properties, and uses of poly(oxyethylene- (9-oxypropylene) have been reviewed (98). 

K. Bauer, in D. Garbe, ed.. Common Fragrance and Flavor Materials Preparation, Properties and Uses, VCH, Weioheim, Germany, 1985. 

PVC is so versatile that it can be compounded for a wide range of properties and used in a wide variety of markets. Most of the products are... 

R. N. Traxler, Its Composition, Properties and Uses, Reinhold Publishing Co., New York, 1961, Chapt. 6. 

R. P. W. Scott, Small Pore Liquid Chromatography Columns—Their Properties and Uses, Wiley-Interscience, John Wiley Sons, Inc., New York, 1984. 

Typically, grape skin extract has a specific gravity of 1.13 g/mL at 20°C, a solids content of 28—32° Brix (=t3°), a pH of 3.0, and a color strength as anthocyanin of about 1.25% (as measured at 520 nm ia pH 3.0 citrate buffet). Grape skin extract is also available as spray-dried powders with color values three to four times those of the liquid. The properties and uses of grape skin extract ate similar to those of grape color extract. 

W. Kampfer, and E. Stieg, Jr., Color Eng. 44, 35—40, 44 (1967). A description of the manufacture, properties, and uses of titanium dioxide as a colorant for paint, food, plastics, and other materials. 

Tritium is the subject of various reviews (6—8), and a book (9) provides a comprehensive survey of the preparation, properties, and uses of tritium compounds. Selected physical properties for molecular tritium, are given in Table 1. 

PROPERTIES AND USE IN ANALYSIS OF WATER-SOLUBLE POLYMER - POLYVINYLPYRROLIDONE... 

---