bluuebunny/crossref_metadata_2025 huggingface dataset:
N‐Halamines
Authors: Worley S. Davis , Wojtowicz John A.
Published: July 2004

N‐Halamines are inorganic and organic compounds in which oxidative halogen is chemically bonded to nitrogen. They have both research and commercial importance, particularly in the areas of disinfection of water and stabilization of free halogen. TheN‐halogen bond is formed by reaction of an amine, imine, amide, or imide with halogen, hypohalous acid, or hypochlorite. Only the chloro and bromo derivatives are of commercial importance. The physical and chemical properties, preparation, manufacture, uses, safety and handling, toxicity, and economic aspects of chloramines and bromamines are discussed. The chemistry of chloramines and bromamines is diversified not only because nitrogen and halogen act as reaction sites, but because of the different modes by which these functionalities react. Research activity on synthetic applications of chloramines and bromamines continues to be high.

In aqueous solution, the chloramines and bromamines generally undergo hydrolysis to varying degrees forming hypochlorous and hypobromous acids. Thus generally theseN‐halamines can be considered as halogen release agents, and many, eg, chloroisocyanurates, find use in bleaching, disinfecting, and sanitizing applications. Others, such as halogen derivatives of ammonia, are important because they are industrial process intermediates (monochloramine) or of significance in water treatment (mono‐, di‐, and trichloramine). The most recent work has concerned covalent attachment ofN‐halamine moieties to insoluble polymers so as to create biocidal materials with excellent potential for commercial utilization.
Chocolate and Cocoa
Authors: Zoumas B. L. , Azzara C. D. , Bouzas J.
Published: July 2004

Most chocolate and cocoa products consist of blends of roasted cocoa beans chosen for flavor and color characteristics. Cocoa may be blended in the bean, nib, or liquor state before going on to the chocolate making or pressing phase. Pressing separates the liquor into cocoa powder and cocoa butter, ∼ 50:50.

The ingredients used for making chocolate are cocoa liquor, cocoa butter, sugar, lecithin, and vanillin for dark chocolate, plus milk solids for milk chocolate. These ingredients are mixed and then refined so the particle size of the ingredients is reduced to make the resultant chocolate smooth.

After refining, the chocolate is conched, during which changes to viscosity, flavor, and texture occur. After conching, the product is standardized to fat content and viscosity, is tempered to obtain the correct form of fat crystal, and is deposited into molds to form the final shape. The chocolate is removed from the molds after cooling and then is wrapped and packaged ready for shipment to the customer.
Choline
Authors: Gidding Curtis E.
Published: July 2004

The quaternary ammonium compound choline or a precursor is needed in the diet as a constituent of certain phospholipids (lecithin) universally present in protoplasm. This makes choline an important nutritional substance. It is also of great physiological interest because one of its esters, acetylcholine, appears to be responsible for the mediation of parasympathetic nerve impulses and has been postulated to be essential to the transmission of impulses of all nerves. Acetylcholine and other more stable compounds that simulate its action are pharmacologically important because of their powerful effect on the heart and on smooth muscle. Choline is used clinically in liver disorders. Its principal commercial use is as a constituent in animal feeds usually as the chloride.

Choline's properties, biological functions, occurrence, preparation, analysis, and uses are discussed. Some of its salts and derivatives are also described.
Chromium Compounds
Authors: Page Billie J. , Loar Gary W. ,   Updated by Staff
Published: July 2004

Chromium compounds and their important uses are described. Chemical properties of the low valence compounds, Cr(‐II) through Cr(I), and those of Cr(IV) and Cr(V) are discussed as are those of the commercially important oxidation states of Cr(II), Cr(III), and Cr(VI).

Sodium chromate and dichromate production from imported chromite ore, and the production of other chromates, dichromates, and chromic acid are summarized. The manufacture of water‐soluble trivalent compounds is also given. Regulations concerning shipments, specifications, and analytical test methods are discussed as are the health and safety factors of chromium compounds.

The environmental impact and waste management practices of chromium compounds is also of importance. Chromium compounds of various oxidation states are used commercially as pigments, in metal finishing, leather tanning, drilling muds, and in wood preservation. Chromium compounds are also used in alloys, batteries catalysts, photosensitive gels, and as reagent grade chemicals.
Coal Conversion Processes, Cleaning and Desulfurization
Authors: Chiang Shiao‐Hung , Cobb James T.
Published: July 2004

An overview of coal cleaning and desulfurization schemes designed to minimize contaminants from coal combustion systems is presented. Coal cleaning can be divided into two basic categories: physical and chemical processes. Physical cleaning involves specific gravity‐controlled processes. Surface‐force‐controlled processes, such as flotation and selective agglomeration, dominate newer developments. Whereas chemical and biological coal cleaning processes have shown potential to produce deep‐cleaned coal, most of these processes have yet to be tested at commercial scale.

As coal is burned, and also following combustion, sulfur dioxide can be removed at a number of locations as the combustion gas gives up its heat and entrained particulate matter before being exhausted to the atmosphere. Atmospheric and circulating fluidized‐bed combustors are commercially available, and pressurized fluidized‐bed combustors are being developed to collect sulfur dioxide in limestone injected into the combustion zone. Limestone injection just after combustion in a pulverized coal furnace, and processes whereby lime or limestone can be injected into the ductwork following the boiler and in dry scrubbers for desulfurization, have been installed at coal‐fired power plants and these and both wet and dry regenerable scrubbers are described.
Metal Surface Treatments, Cleaning
Authors: Murphy Donald P.
Published: July 2004

Metal surface cleaning is the beginning of any metal treatment. The cleaners for metal surfaces may be classified as solvent‐based or aqueous. Usage of solvent‐based cleaners is declining. Whereas aqueous cleaners may be acidic, neutral, or alkaline, alkaline cleaners are the most widely used. The types of components typically found in an alkaline cleaner for specific types of metals or alloys, together with cleaning temperatures and other conditions of operation, are discussed. The most common mechanisms of soil removal are presented, as well as descriptions of the various cleaner application methods such as spray, immersion, electro‐ and barrel cleaning.
Coatings, Marine
Authors: Brady Robert F. , Drisko Richard W.
Published: July 2004

Marine coatings technology and the role of marine coatings in controlling corrosion are described. Marine coatings aid in the prevention of corrosion of ships, buoys, offshore drilling platforms, piers, locks, and bridges. These coatings impart surface properties, such as fouling protection, which cannot be attained by any other means. Regulations concerning coatings materials and surface preparation methods are summarized. The principal types of modern marine coatings, surface preparation methods, and application techniques are described, advantages and drawbacks are specified, and criteria for selection and use are given. Coating components such as pigment, resins, and additives are provided. The performance requirements for coatings in various ship areas are identified, and the coatings which meet these requirements are described.
Coffee
Authors: Wasserman Gerald S. , Bradbury Allan , Cruz Theodore , Penson Simon
Published: July 2004

This article presents a description of coffee processing technology; coffee chemistry and coffee consumption trends. Special attention is given to green coffee processing, the chemistry of green coffee, the effects of roasting and brewing upon chemistry, as well as the chemistry of instant or soluble coffee. Processing and packaging of roasted, ground, instant and decaffeinated coffees are discussed. The economics of green coffee, as well as the import and world production figures for 1999–2000, are included. Emerging activity in coffee biotechnology is also discussed.
Colloids
Authors: Schramm Laurier L.
Published: July 2004

A colloid comprises a collection of small particles, droplets, or bubbles of one phase having at least one dimension between ∼ 1 and 1000 nm, and dispersed in a second phase. Either or both phases may be in gas, liquid, solid, or supercritical phase states. Another property that distinguishes colloidal dispersions is the extremely large area of the interface between the two phases compared with the mass of the dispersed phase. A consequence is that any chemical and physical phenomena that depend on the existence of an interface become very prominent in colloidal dispersions. Colloidal systems are important because they feature prominently, in both desirable and undesirable contexts, in a wide variety of practical disciplines, products and industrial processes. The problems associated with colloids are usually interdisciplinary in nature and a broad scientific base is required to understand them completely. This article provides an introduction to the field of colloids, emphasizing the wide range of practical and industrial applications.
Colorants for Plastics
Authors: Charvat Robert A.
Published: July 2004

Colorants in plastic consumer and industrial products play a major role in their acceptance by the consumer. Color is what sells the product to the consumer. Industrially, color plays an important role in identifying parts, as an example. What a dull world it would be without color! Coloring a product correctly, however, is not an easy task. Years ago, the coloring of materials was a true art. Today, the art is still there, but science now plays a much greater role.

Colorants are generally classified into three distinct groups: organic pigments, inorganic pigments, and soluble dyes. These three major groups are available in a number different physical forms designed to maximize their effectiveness and efficiency of use. Each is quite different in how it brings color to a product and how they may affect other properties not visible, which could make a product more effective. Colorants and other additives for that matter can positively and/or negatively effect such properties as strength, impact resistance, electrical properties, opacity–transparency processing parameters, durability to heat, chemical attack and weathering if the product is destined for outdoor use.
Combustion Science and Technology
Authors: Sharifi Reza , Pisupati Sarma V. , Scaroni Alan W.
Published: July 2004

In the introductory section, some of the fundamental concepts and theories of combustion science such as higher heating value of fuel, air to fuel ratio, flammability limits, ignition, and flame temperature are discussed. Premixed and diffusion flames are then defined and some guidelines for their analysis and understanding are outlined. Finally, the fundamentals of coal combustion are discussed. Then the technology involved in the combustion of the three most common types of fossil fuels, namely gas, oil, and coal, is discussed along with some design parameters for the combustion chambers. The most recent advances in fossil fuel combustion technology are pointed out and some of the associated problems with each fuel are explained. Finally, the impact of fossil fuels on the environment and some of the techniques available for reducing their impact are pointed out.
Boron Hydrides, Heteroboranes, and their Metalla Derivatives (Commercial Aspects)
Authors: Barendt Joseph , Dryden Beth
Published: July 2004

Sodium tetrahydroborate, NaBH4, more commonly called sodium borohydride, is the most widely used commercial boron hydride. Sodium borohydride is available as a 12% solution in caustic soda and in solid form either as powder or pellets. Solid sodium borohydride does not ignite upon contact with moisture and is not shock‐sensitive. These characteristics allow it to be handled safely in air. Because it does liberate hydrogen upon contact with water it should be handled with care. The predominant use for sodium borohydride is in wood pulp bleaching. The next largest commercial use is as a reducing agent of functional groups in organic synthesis. A significant application in pharmaceutical synthesis is the stereospecific and selective reduction in steroid production. Borane complexes are the most widely used commercial boron compounds, after sodium borohydride. Examples used in organic synthesis are amine borane complexes and borane complexes of tetrahydrofuran and dimethyl sulfide. Although not commercial as yet, boron neutron capture therapy (bnct) involves the uptake of boron compounds enriched with the boron‐10,10B, isotope, selectively accumulating in cancerous tumors.
Semiconductors, Compound Semiconductors
Authors: Drummond Timothy J. , Biefeld Robert M. , Sherwin Marc E. , Crawford Mary H.
Published: July 2004

The term compound semiconductor encompasses a large number of materials, most of which crystallize in either the zincblende, wurtzite, or rock salt crystal structures. This article focuses primarily on the properties of the most extensively studied Groups III and V and Groups (2, 12) II–VI compound semiconductors. A summary of the physical (mechanical and electrical) properties of the zincblende cubic semiconductors, a description of the metal organic chemical vapor deposition process, the physics and applications of electronic and photonic devices, and the fabrication process technology in use to create both electronic and photonic devices and circuits are discussed.
Computer‐Aided Design and Manufacturing (CAD/CAM)
Authors: Pao Y. C. , Clements L. D.
Published: July 2004

Design has a long history but computer‐aided design (CAD) offers a new, modern connotation. With the exception of the physical processes, such as cutting, forging, and mixing used to a manufacture items, the commonly discussed topics in computer‐aided manufacturing (CAM), such as material planning, process and procedure designs, numerical control, and scheduling, can also be considered CAD because design is involved. This article reviews the history of computer‐aided design beginning with ENIAC, the first electronic computer, which was developed for the army during World War II, through the recent introduction of a computer that has a speed of 100–250 million floating‐point operations per second (flops). In automating chemical processes and computations, companies must decide whether to use commercial software packages or to develop in‐house CAD/CAM programs. Many of the underlying principles employed in the design of the prevailing commercial software packages are discussed. These principles can also guide the development of in‐house programs. The topics covered include absorption to waste management, and range from drafting isometric pipeline systems and the interactive manipulation of block diagrams involved in chemical processes to the solid modeling of molecular structures.
Petroleum, Composition
Authors: Robbins Winston K. , Hsu Chang Samuel
Published: July 2004

Petroleum is a complex mixture, consisting primarily of hydrocarbons, derived from ancient living organisms deposited as geological sediments. The composition of petroleum conveniently described in terms of refinery distillation varies greatly from one source to another. The naphtha, middle‐distillate, vacuum gas oil, and vacuum resid fractions increase in complexity and molecular weight. The elemental and molecular composition of these fractions show a general shift from simple saturated hydrocarbons in the naphtha to more complex aromatics and eventually sulfur‐, nitrogen‐, and oxygen‐containing hydrocarbons in the heavier distillates. The nondistillable vacuum resid includes still larger molecules that appear to contain several groups of the benzologues of smaller molecular structures linked together plus the largest portion of the S, N, O, and metal compounds. Complete compositional analysis of petroleum is possible only for low boiling fractions. For high boiling fractions, composition is usually determined by compound types and carbon number ranges. For nonvolatile fractions, only average structure can be obtained. Elaborate separation into well‐defined fractions can aid in compositional analysis by sophisticated analytical techniques.
Noble‐Gas Compounds
Authors: Schrobilgen Gary J. , Moran Matthew D.
Published: July 2004

Noble‐gas reactivity was discovered in 1962 when Neil Bartlett showed that xenon gas was oxidized by PtF6to XePtF6. Pursuant to his discovery, numerous xenon and krypton compounds were synthesized in macroscopic quantities. Among the noble‐gas elements, xenon has the most extensive chemistry, and can possess formal oxidation states of 0, +½, +2, +4, +6 and +8 in its compounds by forming fluorides, oxides and oxide fluorides as well as derivatives in which xenon is bonded to polyatomic groups through oxygen, nitrogen and carbon. In addition, several compounds containing Xe‐Au bonds and one compound containing an Xe‐Xe bond are known. Other xenon‐element bonds are known in the gas phase or in low‐temperature matrices, which provide examples of Xe‐H, Xe‐Si, Xe‐S, Xe‐X (X = Cl, Br, I) and Xe‐U bonds. Krypton chemistry is more limited. Only compounds with krypton in the +2 oxidation state are known, namely, KrF2, salts of the KrF+and Kr2F3+cations, by analogy with xenon, Kr(OTeF5)2and several species containing Kr‐N bonds. Several gas‐phase and matrix‐isolated species in which krypton is bonded to carbon, hydrogen and halides other than fluorine are also known. Radon is believed to form RnF2and RnF+by analogy with krypton and xenon. The only argon species that are known are the ArF+cation, which has been observed in the gas phase, and HArF, which has been stabilized in a low‐temperature argon matrix. To date, no argon, neon or helium compounds have been isolated in macroscopic amounts. Noble‐gas compounds have been utilized as oxidizers and oxidative fluorinating agents in chemical syntheses.
Computer‐Aided Chemical Engineering
Authors: Johns W. R.
Published: July 2004

Computer‐Aided Chemical Engineering is reviewed from its beginnings in the 1950s to the present state in which virtually all chemical engineering is computer‐aided. Over 200 computer‐based computations routinely undertaken by chemical engineers are listed. Computer‐aids are used at every stage from deciding what chemical species to make, through the conceptual design of the processes, the detailed design, the on‐line control, optimization and retrofit design, up to the decommissioning. Computer‐aids are important for assessing and minimizing environmental impacts and hazards. This chapter does not discuss any of these topics in detail. It concentrates on the design of reliable software and the correct use of software supplied by third parties. Guidance is given for designing software that properly meets the technical requirements of the end users. The program structure and test procedures necessary to validate the software are described. Methods for ensuring that the program properly incorporates the physical models on which it is based are outlined including emphasis on dimensionally consistent programming. The importance of data validation is emphasized. It is further emphasized that these design guidelines apply equally to models written in special‐purpose modeling systems as they do to models written in general‐purpose computer‐programming languages. The elements of numerical analysis are introduced and illustrated with common examples from chemical engineering. Even simple computations, such as log–mean temperature difference, can be grossly in error if the numerical limitations of computers are ignored. Reliable, easily solved models should be near‐linear and explicit, and steps to achieve such models are included. The treatment is designed to be adequate for engineers writing small programs, or small parts of larger programs. References are introduced to enable professional engineering programmers to pursue the topics in greater depth.

End‐users of chemical engineering software have responsibility for the decisions taken based on computed results. They must ensure that the software is adequate for its purpose, that all data is properly validated, and that the computed results are properly interpreted. They are also responsible for scoping the uncertainties in the computation and assessing their impact on the decisions taken. This chapter describes the steps that should be taken to ensure that computer aids are properly used and decisions are properly reached. It gives further reading for engineers likely to manage projects in which extensive use is made of computer tools.

A brief introduction is given to some of the rapidly advancing areas of computer‐aided chemical engineering.
Computer Technology
Authors: Watson Ian
Published: July 2004

Computers are an integral part of modern chemistry. As computers have become faster, less expensive, and more functional, chemists have come to rely more and more on their use. These trends are expected to continue. This article provides brief overviews of the principal classes of computers commonly used in chemistry today, together with some of the roles they play. Within each class, there is discussion of the historical significance and changing role of the computer for chemistry. Emphasis is on computers that find application in computational chemistry and other numerically intensive areas. Given the rapidly accelerating rates of change in computer technology, it is expected that this article will provide mostly a historical perspective soon after its publication.
Contraceptives
Authors: Hahn D. W. , McGuire J. L. , Bialy Gabriel
Published: July 2004

Millions of people throughout the world use a variety of methods to regulate human fertility, including oral contraceptives, sterilization, vaginal and barrier contraceptives, long‐acting injectable and implantable contraceptives, intrauterine devices, and natural family planning. Each of these methods has its advantages and disadvantages, and contraceptive use varies significantly by country and geographical region. It is generally accepted that none of these methods represents the ideal method of fertility regulation for everyone, and research is focused on new methods such as contraceptive vaccines, GnRH analogues, and progesterone antagonists in many countries throughout the world today.
Contact Lenses
Authors: Lai Yu‐chin , Wilson Alan C. , Zantos Steve G.
Published: July 2004

Contact LensesContact lenses are small, hemispherical‐shaped optical devices placed in contact with the transparent tissue at the front of the eye called the cornea. Contact lenses are used to correct vision deficiencies such as myopia (nearsightedness), hyperopia (farsightedness), presbyopia (loss of near focusing power with age), and astigmatism. An increasingly common use of contact lenses is to change the color of a normal eye or to improve the appearance of an eye disfigured by injury or disease. Contact lenses can also be used as therapeutic devices in the medical treatment of certain eye diseases or injuries. The 1980s saw the widespread introduction of lens products made of more oxygen‐permeable materials, ie, rigid gaspermeable (RGP) materials that made PMMA lenses virtually obsolete and high water content hydrogels that competed with HEMA‐based lenses. Research continues for materials having improved oxygen permeability, deposit resistance, and comfort. In addition, there is the search for breakthrough lens designs, such as bifocal contact lens products. Competition includes developing new surgical techniques, eg, excimer laser refractive surgery that modifies the shape of the cornea to correct vision, potentially without the use of eyeglasses or contact lenses. No particular contact lens type or product is considered universally superior. To remain safe and efficacious on the eye, contact lenses must maintain clear and wetted surfaces, provide an adequate supply of atmospheric oxygen to and adequate expulsion of carbon dioxide from the cornea, allow adequate flow of the eye's tear fluid, and avoid excessive abrasion of the ocular surface or eyelids, all under a variety of environmental conditions. Clinical experience has shown that certain types of lens materials are more prone to deposit problems. All contact lenses can be divided according to the wearing modality. It is convenient to classify lenses according to whether they are rigid (hard) or flexible (soft). Some newer materials give rise to lenses that can be termed semirigid, semisoft, and the combination soft–rigid. The flexibility of a contact lens material dictates, to a large extent, the design of the lens. Not every polymer can be manufactured successfully into a contact lens. Several important properties for both ocular physiology and patient handling are required of a material for a contact lens application. Various lenses are discussed:rigid (hard) lenses; hydrogel contact lenses (includes silicone and fluorohydrogels); flexible nonhydrogel lenses; Tinted lenses; and surface‐modified lenses.Today, most contact lens materials, including xerogels, ie hydrogels in their dry state, can by produced in a disklike form (button) that allows lathe cutting for accurate manufacture of contact lenses. Cast molding is an increasingly used manufacturing process for both rigid gas‐permeable and hydrogel contact lenses.
Packaging, Containers for Industrial Materials
Authors: Olsson David L. , Chapman A. Ray
Published: July 2004

Packaging fulfills several important functions in the safe delivery of chemical products through the distribution system to customers: containment, protection, use features, and communication. Development of industrial packaging with these functions in mind is critical for the safe efficient delivery of industrial products.

There are many regulations making demands on package development, including domestic rail and motor freight classifications as well as other carrier requirements, and U. N. recommendations for international transport of dangerous goods (perhaps virtually all chemicals), which are restated in U.S. Department of Transportation regulations.

Many types and sizes of industrial packages for chemicals are in use, ranging from small boxes, pails, and drums, through intermediate bulk containers, to specialized rail cars. The variety of packaging alternatives, sizes, materials, and applications are all discussed.
Packaging, Converting
Authors: Batelka Joseph J.
Published: July 2004

Various types of paper and paperboard packaging are discussed with respect to the various package manufacturing processes and the materials and chemicals used in these processes. Specific package types described include corrugated paperboard boxes, solid fiber paperboard boxes, multiwall paper bags, paper grocery sacks, paper retail bags, folding paperboard cartons, fiber drums, and fiber cans. The principal categories of uncoated, coated, nonwet‐strength and wet‐strength paper and paperboard substrates are discussed. The various typical paper mill and package plant coatings and chemical additives applied to achieve various package properties are listed. The package performance characteristics covered are moisture resistance, humidity resistance, oil and grease resistance, abrasion resistance, adhesion release properties, nonskid properties, flame‐retardant properties, static electricity control, noncorrosive properties, and gloss. Printing inks and process steam boiler chemicals are specifically excluded from the discussion.
Coordination Compounds
Authors: Fromm Katharina M.
Published: July 2004

This article reviews coordination compounds starting with their definition. It gives an overview on the classification of ligands, deals with the most common examples of nomenclature, and describes the possible isomers encountered with the described ligand types. A new chapter of examples of representative coordination compounds throughout the Periodic Table of elements has been added in order to show the different behavior of coordination found for alkali and alkaline earth metal ions, main group elements, transition metals, and rare earths. These examples are followed by the theories of coordination and bonding, as well as their chemical and physical properties, ie, stability, steric selectivity, reactivity comprising oxidation and reduction, photochemistry and magnetism. In a later section, applications of coordination compounds will be given. The role of these compounds in industrial processes as well as potential applications in research are described, and examples are shown. This article also gives some examples of supramolecular compounds, which are part of coordination chemistry, however, supramolecular chemistry is given a chapter on its own elsewhere in this series.
Copper
Authors: Kundig K. J. A. , Dresher W. H.
Published: July 2004

Copper and its various alloys are used in industrial and consumer applications because of high electrical and thermal conductivities, wear and corrosion resistance, and mechanical and aesthetic properties. These metals are vital to nearly every industrial sector. Uses of copper and alloy mill products may be broken down into five principal markets: building construction, electrical and electronic products, industrial machinery and equipment, transportation, and consumer and general products. In addition, copper and its alloys are a strategic material essential to the production of equipment critical to the U.S. economy and national defense.

The various copper minerals, mining, ore treatment, smelting, and refining are discussed as is fabrication of products and the chemical reactions specific to these processes. There have been significant process innovations in the copper industry, particularly in hydrometallurgy, solvent‐extraction technology, and continuous casting production methods.

Pure copper is most often produced by electrorefining. Sulfuric acid is a principal by‐product of copper smelting. The United States is a world leader in smelting and refining capacity. It is the second largest copper ore producer and repository of one‐fifth of the world's recoverable reserves. U.S. and world production is discussed.
Corrosion and Corrosion Control
Authors: Natishan Paul , Moran Patrick
Published: July 2004

This article discusses the various types of corrosion and the fundamental mechanisms responsible for corrosion. The importance of electrochemical reactions in causing and controlling corrosion phenomena is emphasized. The influence of environmental factors and metallurgical variables is reviewed and the predominant corrosion modes for technologically significant metal and alloy systems are discussed. The various methods of corrosion prevention such as cathodic protection, coatings, and inhibitors are also described. Throughout the article, references to additional information are included.
Cosmetics
Authors: Rieger Martin M.
Published: July 2004

General cosmetic industry regulations and practices, and cosmetic compositional details of various products (except fragrances) are presented. Coverage emphasizes U.S. regulations concerning the use of color additives and the differences between cosmetics and over‐the‐counter (OTC) drugs. Safety testing procedures, means for preventing microbial contamination, and the usage of several groups of cosmetic ingredients are discussed. The preparation of emulsions and of products in stick form is reviewed. The formulations of cosmetic and OTC skin preparations, cleansing products for skin, hair, and the oral cavity, nail‐care products, hair preparations for styling, waving, and coloring, and makeup products is described.

The utility and benefits of cosmetic ingredients in various types of cosmetics are discussed and those ingredients are listed. Literature references to specific cosmetic formulations are provided.
Packaging, Cosmetics and Pharmaceuticals
Authors: Rosette Jack L.
Published: July 2004

Cosmetics and pharmaceuticals each have their own special packaging requirements, although the primary purpose of packaging for both is to provide a means to store and distribute the product until the entire contents of the package are used. Cosmetic packaging is used to enhance the image of the product, and though pharmaceutical packaging has the same basic objectives, product stability and safe packaging requirements dictate different parameters regarding tampering prevention and child safety requirements of the FDA and the Consumer Product Safety Commission.

The FDA Rule requires the use of tamper‐evident packaging on all over‐the‐counter drugs and some cosmetics. However, if a product in an adulterated form could harm a consumer, manufacturers have the responsibility of protecting the product and consumer against tampering, meaning that tamper‐evident packaging transcends FDA regulations. No single feature is best for all products and all features can be violated in some manner, but effective tamper‐evident features provide greater difficulty in doing so. Consumers should be aware of what to look for in tamper‐evident packaging and pay attention to what product is being used.
Coumarin
Authors: Boisde Paul M. , Meuly Walter C.
Published: July 2004

Coumarin is an important aroma chemical widely used in the perfumery, soap, and cosmetic industries for its characteristic herbaceous odor and as a valuable odor fixative. It also has several other unrelated industrial uses. It occurs naturally in many plants and was first extracted from Tonka beans in 1820. Coumarin is a crystalline solid. The commercial product is manufactured synthetically and the usual preparation methods start fromo‐cresol, phenol, and most currently from salicylaldehyde. The perfume‐grade product is highly purified and purification methods are given as well as the manufacturers' specifications. Production figures and commercial prices in the United States are listed since the 1940s.

Health and safety data are reported. Since 1954, the use of coumarin in foods has been banned in the United States by the FDA. The carcinogenicity of coumarin has been debated. Recent studies have led IARC to classify coumarin as a Group 3 chemical indicating insufficient evidence of carcinogenicity in humans.

In addition to its use in the fragrance industry and as an industrial odorant or odor masking agent, coumarin is also an electroplating adjuvant. Coumarin and some of its derivatives are used as fluorescent brighteners and as pharmaceuticals in anticoagulant therapy. Several of the most important coumarin derivatives are described including 3,4‐dihydrocoumarin, 3‐ and 6‐methyl coumarins, 4‐hydroxycoumarin, umbelliferone, dicoumarol, and warfarin.
Cumene
Authors: Hwang S. Y. , Chen S. S.
Published: July 2004

Production of cumene was considered a rather dull business for many years, but has generated considerable excitement recently for two reasons. First, the demand for cumene in the production of polycarbonates is accelerating, owing to the broadening applications of polycarbonates. Second, successful development and commercialization of the zeolite‐based technology for the production of cumene has rendered obsolete the older processes based on solid phosphoric acid and aluminum chloride. Within a period of just over 2 years during 1996–1998, over one‐half of the cumene capacity in the world was converted to the new technology. This article provides technical insights into the successful new zeolite‐based process, as well as the older processes based on solid phosphoric acid and aluminum chloride.
Cyanides
Authors: Pesce Lawrence D.
Published: July 2004

The industrially important cyanides are hydrogen cyanide; sodium, potassium, and lithium cyanide; ammonium cyanide; and calcium cyanide. These compounds have been variously used as poisons and fumigants, in electroplating baths, in extractive metallurgy, and in the synthesis of such diverse chemicals as pharmaceuticals, dyes, and chelating agents.

Hydrogen cyanide is the most used cyanide, and it is produced by the Andrussow process. The other cyanides are generally prepared by the neutralization or wet process. Compounds differ in reactivity, purity, price, and stability. Safe practices for handling these compounds are discussed.
Dyes, Cyanine
Authors: Sturmer David M.
Published: July 2004

Cyanine dyes and the related merocyanines and oxonols are commercially important dyes for high technology uses, including spectral sensitization of photographic films, optical filtering/light modulation, dye lasers, and biological staining agents. The primary chromophores and heterocycles in these dyes are outlined with specific reference to chemical reactions that allow the synthesis of almost every type of cyanine and related dye. Known structure–property relationships for the cyanines are extensive, and examples are included for properties such as color, substituent effects, solubility, self‐association (aggregation), electrochemical behavior, photochemical reactions, and biological uses.
Cyanocarbons
Authors: Webster Owen W.
Published: July 2004

Cyanocarbons are organic compounds in which a substantial portion of the total functionality consists of cyano groups. As a consequence of the large number of cyano groups, the cyanocarbons are highly reactive electrophilic molecules. The most important members of the cyanocarbon family are tetracyanomethane, hexacyanoethane, tetracyanoethylene (TCNE), tetracyanoquinodimethan (TCNQ), hexacyanobutadiene, dicyanoacetylene, hexacyanobenzene, tetracyanoquinone, tricyanomethanide, pentacyanopropenide, pentacyanocyclopentadienide, tetracyanoethylene oxide, tetracyanofuran, tetracyanothiophene, tetracyanodithiin, diaminomaleonitrile (DAMN), diiminosuccinonitrile, tetracyanopyrazine, diazotetracyanocyclopentadiene, diazodicyanoimidazole, tetracyanopyrole, tricyanoimidazole, and pentacyanopyridine.

Examples of unusual reactivity are numerous. TCNE forms colored charge‐transfer complexes with aromatic hydrocarbons, tetracyanoethylene oxide adds to olefins by cleavage of its carbon‐carbon bond, and TCNE and TCNQ react with metals to produce anion radicals.
Cyanuric and Isocyanuric Acids
Authors: Wojtowicz John
Published: July 2004

Cyanuric acid has been known for over 200 years, but achieved commercial importance only in the mid‐1950s primarily via its derivatives. The chemistry of cyanuric acid is diversified because of multiple reaction sites.N‐Chlorination of cyanuric acid produces chloroisocyanurates that are widely used as disinfectants, sanitizers, and bleaches. The triallyl and tris(2‐hydroxyethyl) derivatives are employed as cross‐linking and curing agents, and tris(2,3‐epoxypropyl)isocyanurate is used in weather‐resistant powder coatings. Melamine cyanurate finds significant use as a fire retardant in plastics. Considerable interest has developed in the use of cyanuric acid for reduction of nitrogen oxides in exhaust gases from combustion of oil, gas, and coal.

Nomenclature is based on the keto–enol tautomers. The trihydroxy form is variously designated cyanuric acid,s‐triazine‐2,4,6‐triol or 2,4,6‐trihydroxy‐s‐triazine. The trioxo structure, ors‐triazine‐2,4,6(1H,3H,5H)‐trione is the basis for the isocyanuric acid nomenclature. The triazine‐based system is preferred in the scientific literature and is used by government regulatory agencies; however, the less cumbersome (iso)cyanurate designations persist in commerce. The keto form normally predominates in cases of keto‐enol tautomerism. In alkaline solution, the anion formed is that of the hydroxy tautomer. Through common usage, both forms are collectively called cyanuric acid (CA).
Cyclohexanol and Cyclohexanone
Authors: Fisher William B. , VanPeppen Jan F.
Published: July 2004

Cyclohexanol is a colorless, viscous liquid with a camphoraceous odor. It is used chiefly as a chemical intermediate, a stabilizer, and a homogenizer for various soap and detergent emulsions, and as a solvent for lacquers and varnishes. Cyclohexanone is a colorless, mobile liquid with an odor suggestive of peppermint and acetone. It is used chiefly as a chemical intermediate and as a solvent for resins, lacquers, dyes, and insecticides.

Both cyclohexanol and cyclohexanone are produced commercially by the catalytic oxidation of cyclohexane or the catalytic hydrogenation of phenol. Information presented includes physical properties; manufacture; reactions, derivatives, and uses; economic aspects; specifications and analysis; and health and safety factors.
Cyclopentadiene and Dicyclopentadiene
Authors: Cheung T. T. Peter
Published: July 2004

Cyclopentadiene and dicyclopentadiene, which occur as byproducts in the steam cracking process in ethylene plants, are the major ingredients in the production of hydrocarbon resins, unsaturated polyester resins, elastomers, pesticides, flame retardants and a host of specialty chemicals. The versatility of cyclopentadiene as the building block in so many chemicals stems from the high reactivity of its conjugated double bonds. They react readily with dienophiles, compounds with ethylenic or acetylenic unsaturation, to give Diels‐Alder adducts, with oxygen and halogen to give oxygenates and halide derivatives. Cyclopentadiene dimerizes readily, via the Diels‐Alder mechanism, to dicyclopentadiene at ambient conditions. The dimerization is highly exothermic. Because of its reactivity, cyclopentadiene is normally available only in the stable dimer form. Pure cyclopentadiene can be produced in‐situ by the thermal cracking of the dicyclopentadiene at a temperature near the normal boiling point of the dicyclopentadiene.
Dairy Substitutes
Authors: Harper W. James
Published: July 2004

Dairy substitutes encompass a wide range of products and are manufactured by most food companies, utilizing fats, proteins, carbohydrates, and functional food additives including starches, gums, and emulsifiers. The specific requirements for individual ingredients is dependent on the type of product being manufactured and the processing methods employed. Substitutes are available for every common dairy food.

Products that have gained the largest markets are substitutes for butter and creams. Substitute evaporated milk and whole milk powders have become widely established in Far Eastern countries, where they can replace up to 80% of standard dairy foods. Much of the basis for the development of substitute dairy foods lies in the lower cost of vegetable fats compared to butter fat. In certain cases the substitute food products have largely replaced dairy products. This is particularly true for vegetable‐based spreads (such as oleomargarines and related products, whipped toppings, and coffee whiteners).

Casein, a milk protein, is widely used in many dairy substitutes. Imitation dairy foods that are considered to be important in human nutrition must be nutritionally equivalent to the dairy product that they imitate.
Defoamers
Authors: Owen Michael J.
Published: July 2004

A review is presented of the materials used to control or eliminate foam in industrial processes and how they function. These materials are classified by their chemical type. Main active liquid‐phase components are hydrocarbon oils, polyethers, and silicone fluids; main solid‐phase components are waxy hydrocarbons and hydrophobic silica. Ancillary agents such as surfactants and carriers are also incorporated in some defoamer formulations. Sources of significant commercial defoamer products are listed. The theory of foaming and defoaming is outlined with emphasis on surface behavior such as entering, spreading, and dewetting phenomena. The role of dispersed hydrophobic solids is highlighted. Applications in various areas are briefly reviewed, including adhesives and sealants, chemical processing, cleaning compounds, construction, fermentation processes, fertilizers, food and beverages, leather, metal working, oil and petrochemicals, coatings, polymers, pulp and paper, textiles, and wastewater treatment. Economic and health and safety factors are considered. Test methods, such as pneumatic, dynamic, shaking, pour, stirring, and blending methods are also briefly reviewed.
Dentifrices
Authors: Pader Morton
Published: July 2004

Dentifrices are compositions used in conjunction with a toothbrush to remove stains from teeth and to leave the mouth feeling clean and refreshed after toothbrushing. A dentifrice has little to do with the control of dental plaque by toothbrushing; the toothbrush plays the primary role. In recent years dentifrices have become vehicles for the delivery of agents to fulfill specific therapeutic and cosmetic functions. These agents include fluoride, to inhibit the incidence of dental caries; pyrophosphates and zinc salts, to inhibit tartar formation; antimicrobial agents, to reduce plaque accumulation; and potassium nitrate, to reduce dentinal hypersensitivity.

Toothpaste, the most popular form of dentifrice, contains an abrasive, a humectant system, a surfactant, one or more gums or resins for cohesiveness and structure, flavor, color, and agents for specific effects. Two types of dentifrice predominate. One contains a relatively low level of an amorphous hydrated silica abrasive and a high level of humectant; the other has a high level of abrasive and a low level of humectant. Dental rinses are adjunctive to toothbrushing with dentifrice, and are discussed briefly. Tooth whiteners are on the market.
Dental Materials
Authors: Tesk John A. , Antonucci Joseph M. , Carey Clifton M. , Eichmiller Fred C. , Kelly J. Robert , Rupp Nelson W. , Waterstrat Richard W. , Fraker Anna C. , Chow Lawrence C. , George Laurie A. , Schumacher Gary E. , Stansbury Jeffrey W. , Parry Edward E.
Published: July 2004

Dentistry is a healing science that involves a huge number and variety of different materials. Restoring diseased teeth and supporting tissues can require the use of ceramics, metals, polymers, inorganic cements, and waxes. These materials are often ties used in various combinations. The one key factor that sets dental materials apart from most other uses of materials is that the clinician is often responsible for the formulation or manufacture of the final material. Most dental materials used to directly restore teeth are delivered in a state were the operating dentist controls the final setting reaction. When fillings are prefabricated in a laboratory, the cements or adhesives used for placing these restorations are still under the control of the operating dentist. For this reason, the physical properties of these materials can only be determined by laboratory simulations and may not completely reflect the properties achieved in actual use. This article describes these materials and their most common uses in clinical dentistry and in dental laboratories.