bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phosphoric Acids and Phosphates
Authors: Gard David R. 
Published: July 2004

AbstractMost commercial applications of phosphorus‐containing materials are based on phosphoric acids and the phosphates. Uses, other than as fertilizer, include applications in detergency, foods and food processing, dental materials, dentifrices, metal surface treatments, flame retardency, etc. Structures and properties of orthophosphoric acid and condensed phosphoric acids are presented. The manufacture of technical‐ and food‐grade phosphoric acids by thermal and wet acid purification processes, as well as some of the uses of the various phosphoric acids, are discussed.The chemistry and properties of orthophosphates and condensed phosphates are presented. Emphasis is placed on alkali metal and calcium salts and their solution properties. Properties specific to condensed phosphate salts such as hydrolysis and metal ion complexation are outlined. Manufacturing schemes for the phosphates are described and attention is given to the control of product properties.
Fluorine Compounds, Inorganic, Phosphorus
Authors: Lindahl Charles B. , Mahmood Tariq 
Published: July 2004

AbstractPhosphorus forms many fluorine compounds, including the binary fluorides, oxyfluorides, thiofluoride, and the various fluorophosphoric acids and their salts. Whereas PF5behaves as a Lewis acid, phosphorus trifluoride behaves as a Lewis base. PF5is used as a catalyst in the electronics industry and in ion implantation for semiconductors. The mono‐, di‐, and hexafluorophosphoric acids are commercially available. Hexafluorophosphoric acid is used in polymerization and preparation of its salts, a number of which exist. Particularly important commercially are sodium monofluorophosphate and potassium hexafluorophosphate, used as a dentifrice additive and as a catalyst for polymerization processes, respectively. The highly toxic fluorophosphate esters have found use in medical applications as well as in warfare. The polymerized esters are also known.
Phosphors
Authors: Srivastava Alok M. , Soules Thomas F. 
Published: July 2004

AbstractLuminescent Materials (Phosphors). Commercial phosphors are typically inorganic powders which convert some form of invisible exciting energy into visible light. For this reason and because they can be quite efficient energy converters, they are commonly used in lamps, television screens, display terminals, x‐ray machines, and a variety of other applications. All of these types of phosphors are discussed in some detail. What phosphors consist of, how they work, how they are made, and some of the technological aspects of their production and use in each application are described. There are a wide variety of materials which luminesce under some form of excitation including common minerals and many organic dyes. However probably less than a hundred of these materials are efficient enough and maintain their efficiency well enough in the environment of their application to have any technological significance. All of these materials are inorganic compounds although there are many more organic compounds which fluoresce. The article is intended to be comprehensive but does not include specialized knowledge about certain phosphor materials or information on new or experimental phosphors or phosphor applications which are not widespread, eg, infrared‐to‐visible converting phosphors which although very interesting are used only in certain laser applications.
Chromogenic Materials, Photochromic
Authors: Samat A. , Guglielmetti R. 
Published: July 2004

AbstractPhotochromism has been defined as a reversible change in the color, or darkening of a material caused by absorption more generally of ultraviolet or visible light. The change in color is due to a modification of the compound structure and implies a change in the absorption spectrum in the visible range (400–750 nm). The reversion of the system to its original state can be driven either by thermal or photochemical energy (photobleaching), or both, depending on the chemical systems. Photochromic systems are naturally divided into two broad categories : inorganic and organic.Within the inorganic category, the most well‐studied and commercially used systems are those containing silver halide crystallites dispersed throughout a glass matrix. The mechanism of the silver halide photochromism is the reversible formation of silver metal. Both the photochemical formation of silver and the thermal reformation of silver halide are catalyzed by copper ions. The silver halide glass systems have been used commercially in photochromic eyewear.Since 1990, the organic photochromic systems have been a dramatic development in the area of variable optical transmission materials and especially for ophthalmic applications. Indeed polymer glasses have also been greatly developed and are compatible with organic pigments. The most common families are those involving electrocyclic reactions and within this class thermoreversible indolinospirooxazines and naphthopyrans have received the most attention.Indolinospirooxazines were the first photochromic compound used in the preparation of commercially acceptable organic photochromic ophthalmic lenses.Moreover, the area of optical memories and switches has been also a prodigious development and the families of photoreversible fulgides and diaryl (or heteroaryl) ethenes have been extensively studied and used for this type of applications.Finally, many potential applications are possible with photochromic pigments using not only the change of color, but the modifications of physico‐chemical properties under the effect of light irradiation.
Photovoltaic Cells
Authors: Gay Charles F. , Eberspacher Chris 
Published: July 2004

AbstractIssues such as global warming, ozone depletion, acid rain, safety of nuclear power plants, and disposal of radioactive waste products are prompting broad debate as to the viability of conventional sources of energy on economic and environmental terms. The combination of a rising demand for reliable, low cost energy and this increased awareness of environmental quality issues is creating new business opportunities for photovoltaics, especially in applications without an installed electric utility grid line.The photovoltaics (PV) industry has been evolving since the 1970s and is rapidly expanding. During the early 1990s, the compound annual growth rate of the PV industry has been greater than 15% with the 1994 worldwide market estimated to be about 68 MW per year; approximately $350 million for PV modules and nearly an equal amount of revenue from the components necessary to make an operational system. Much of this growth is a result of technology cost reduction through economies of scale and evolutionary learning experience as well as market development reflecting the increasing awareness of the versatility, reliability, and economy of PV electric supply systems.The PV market expansion is being filled primarily by well‐established crystalline silicon technologies, which are low cost, large‐area relatives to integrated circuit technology. Incremental improvements in crystalline silicon technologies are lowering PV costs and fueling further market expansion. However, the most significant growth will occur as a result of the increasing involvement of international financing institutions and participation of utilities as marketing organizations.
Metal Surface Treatments, Pickling
Authors: Hacias Kenneth 
Published: July 2004

Abstract
Pickling of metals and metal alloys involves the use of chemical cleaning agents to remove oxides from metal surfaces. The oxides may be in the form of corrosion by‐products or heat treatment scales. Chemical pickling is an extremely effective and economical method for oxide removal, particularly for intricate shapes not readily cleaned mechanically. The choice of acid or alkali pickling product is generally dictated by the base metal or alloy that is to be cleaned. Sulfuric acid is the most commonly used pickling agent for ferrous metals. Mixtures of acids are often a better choice for nonferrous alloys.
Pilot Plants
Authors: Palluzi Richard P. 
Published: July 2004

Abstract
Pilot plants are a generic term covering numerous types of special equipment and systems designed to support or conduct research activities on a scale larger than glassware in a hood. This article briefly covers some of the principal topics and concerns and provides references for further information. Included are some different methods of categorizing pilot plants as well as information about typical units. The importance of scale‐up and planned experimentation are reviewed. The article discusses some of the more common concerns, highlighting the way pilot plants differ from commercial plants. Subjects include design, costs, schedules, and space. Control and instrumentation are also briefly covered. The importance and difficulty of start‐up is noted as is the difficulty of ensuring safety in such atypical equipment and operations.
Pipelines
Authors: Whaley Thomas P. , Long George M. 
Published: July 2004

AbstractPipelines are continuous large‐diameter pipes, usually buried underground, for transporting gases, liquids, or solid slurries over distances ranging from a few to several thousand kilometers. The largest uses are the transport of natural gas or crude oil from producing fields to terminals or processing plants, or petroleum products from oil refineries or natural gas processing plants to distribution points. Pipeline systems in the oil and gas industries consist of small‐diameter gathering pipelines that carry oil or natural gas from producing, wells, and large‐diameter cross‐country pipelines with either compressor stations (for gases) or pumping stations (for liquids) along the route to maintain flow velocities over great distances. Small‐diameter pipe in distribution systems is not part of a pipeline system. Despite great similarities between gas and liquid pipelines in these industries, their regulation has been significantly different. Pipelines are also used to transport anhydrous ammonia, hydrogen, carbon dioxide, molten sulfur, chlorine, nitrogen, oxygen, helium, and other liquid or gaseous chemicals. Freight pipelines transport solids, either as finely divided particles slurried in water or other fluids, or encased in capsules propelled by compressed air or flowing water. Slurry pipelines transport coal, iron ore, phosphate rock, mine‐tailings, municipal wastes, wood fibers, and other finely divided solids suspended in water, the slurry often being dewatered at the terminus. Pipeline transport of materials is probably the safest, least costly, and most environmentally benign of all forms of over‐land transport of materials.
Growth Regulators, Plant
Authors: Cutler Horace G. 
Published: July 2004

AbstractThe arrival of new plant growth regulators on the market in the early 1990s, especially synthetic ones, is in a static state. Many growth regulators continue to be used experimentally, but the transition to approved usage is being delayed for several reasons. On the financial side, a number of mergers, buy‐outs, and other dispositions of chemical companies has led to a decrease in the number of commercial compounds available. Moreover, the cost of registration has prompted some producers to withdraw chemicals from the market. Some older plant growth regulators have undergone several trade name changes, adding confusion to the field.The ideal plant growth regulator should leave no harmful persistent residue in a finished product or crop and the paradigm compounds are ones that have high specific activity, are target specific, and are environmentally biodegradable. The most acceptable growth regulators appear to be those compounds that already occur in nature and elicit certain desirable responses in economic crops.
Plant Location
Authors: Meissner Roland E. 
Published: July 2004

Abstract
Health and safety of personnel and loss prevention are paramount concerns of the chemical industry. Several industry groups encourage members to improve the management of safety and improve manufacturing procedures and practices to minimize hazards. Moreover, state and federal authorities have legislated improvements for the safety of both employees and the public. Particular emphasis has been given to process safety in the legislation and in industry guidelines, and chemical manufacturers are required to follow detailed steps in ensuring adequate training, comprehensive operating procedures, thorough analysis of processes for hazards and investigation of accidents, diligent maintenance of facilities, well‐developed emergency plans, and self‐audits for compliance. Process safety management, including process production hazards and the various engineering and administrative controls, is discussed. The role of plant location, design and operation of facilities, and hazard prevention are presented, as are safe work practices and hazard analysis.
Fractionation, Plasma
Authors: Foster Peter R. 
Published: July 2004

AbstractBlood plasma fractionation is a biopharmaceutical manufacturing operation in which high quality, proteinaceous products are prepared for clinical use from human plasma. Products prepared in this manner include albumin, eg, human serum albumin, and plasma protein fraction, for volume and protein replacement in surgery and for the treatment of injury and disease; coagulation factors, eg, Factor VIII and Factor IX Complex, for the prevention and treatment of bleeding disorders; and immunoglobulins, eg, immune serum globulin and immune globulin intravenous, for the prevention and treatment of infectious diseases and immune disorders.A number of highly integrated bioseparation processes are employed to fractionate human plasma into its different constituents. These range from established cold‐ethanol precipitation technology, devised in the 1940s, to more recently developed solid‐phase adsorption/desorption techniques.The principal developments since 1980 have been immunoglobulin products for intravenous use, and highly effective technologies for the inactivation of viral contaminants, such as hepatitis viruses and Human Immunodeficiency Virus (HIV), which were associated with earlier coagulation factor preparations.
Plastics Testing
Authors: Furches Barbara J. 
Published: July 2004

AbstractPlastics testing covers analytical, thermal, physical, and environmental procedures for determining the composition, structure, as well as mechanical and other responses to a variety of environmental conditions of plastic materials. General uses of Fourier transform infrared, nuclear magnetic resonance, Raman, and X‐ray techniques are reviewed and illustrated with specific examples. Developments in neutron and X‐ray scattering techniques, as well as molecular weight determination techniques such as gel‐permeation chromatography and turbidimetric methods, are also covered. Thermal tests, thermogravimetric analysis, differential thermal analysis, differential scanning calorimetry, and dynamic mechanical analysis are all useful for understanding degradation and phase changes in polymers and their influence on material behavior. New techniques of atomic force microscopy and positron annihilation are allowing studies of the microstructure of polymers and free volume determinations. Several mechanical testing techniques are used in plastics for normal quality control testing and initial application screening of polymers. These tests and those used for more fundamental understanding of polymer response to stress, including fracture mechanics procedures, are referenced. Flammability tests commonly used for plastics include oxygen index, flammability ratings, and smoke generation. Work on the use of cone calorimeters to characterize behavior of plastics under fire conditions is also covered. Finally, environmental testing, chemical exposure, weathering, radiation, and biological agents are reviewed. Emphasis is given to test development or applications reported since 1990.
Polyamides, Plastics
Authors: Palmer Robert J. 
Published: July 2004

Abstract
Polyamides (nylons) are important engineering plastics as well as being well known for fiber applications. This article covers the properties, manufacture, processing and use of polyamide plastics together with information on specifications, sales, pricing and suppliers. Materials discussed include nylon‐6,6, nylon‐6, nylon‐6,9, nylon‐6,12, nylon‐11, nylon‐12, nylon‐4,6, amorphous nylon and other semi‐aromatic nylons. Physical properties described are crystallinity, thermal properties, moisture absorption, electrical properties and flammability. Chemical properties are hydrolysis/polycondensation, thermal degradation, oxidation, UV ageing and effect of chemicals and solvents. Manufacture is described including solid state polymerization, compounding, and pultrusion. Compounding also includes a review of additives and modifications covering lubricants, nucleants, stabilizers, impact modifiers, flame retardants, plasticizers, reinforcements, nanocomposites and polymer blends. The following processing routes are detailed: injection molding, extrusion, film, tubing and pipe, monofilament, rods and profiles, wire and cable coating, blow molding, rotomolding, reaction injection molding (RIM), powder coating and also assembly techniques. Uses and automotive, electrical/electronic, consumer and industrial applications are described. A discussion of recycling is followed by a summary of economic aspects including suppliers, sales and pricing. Specifications, standards and quality control are also reviewed with an indication of appropriate test methods.
Plastics Processing
Authors: Xanthos M. , Todd D. B. 
Published: July 2004

AbstractProcessing of plastics comprises a variety of operations involving flow and shaping of polymer melts into finished articles. For thermoplastic resins the most common processing operations are extrusion and molding. In extrusion, solid plastic resin is melted and then shaped in a continuous part of a defined cross‐section by screw‐conveying and forcing the melt to flow through a die. Die forming is used in pipe and tubing, film, sheet, wire, and cable coating. Molding involves such noncontinuous processes as injection molding, blow molding, rotational molding, and compression molding, in which three‐dimensional parts are made in a closed mold. Molded products are solid, hollow, or foamed. Other thermoplastics operations include thermoforming, calendering, and casting. In contrast to thermoplastics, thermosetting resins use low viscosity components which, through chemical reaction, produce the solid part in the mold. Common processing methods for thermoset systems are compression molding, transfer molding, and injection molding. Specialized techniques developed for fiber‐reinforced thermosets include open‐mold processing, pultrusion, resin transfer molding, and reaction injection molding. Specific processing methods for making low density articles from thermoset polyurethanes are described.
Polishes
Authors: Randall Francis J. , Dwyer Seán G. 
Published: July 2004

AbstractPolishes beautify and protect by coating or refinishing surfaces. Some also clean. Replacing natural waxes with synthetic polymers has improved quality, durability, and convenience. Furniture polishes include liquid or paste solvent waxes, clear or emulsion oils, emulsion waxes, sprays, and impregnated wipes. Each has cleaning, gloss, or durability advantages. Household floor polish trends stress convenience; institutional floor polish trends stress labor reduction through durability or speed. Ingredients include film formers, waxes for repairability, zinc oxide for hardness and removability, and additives for control of leveling or film forming. Some treatments for stone floors modify chemically rather than coat. Car polishes add gloss and remove soil or oxidized paint. Film agents, waxes, or silicones may provide detergent resistance or hide scratches. Industrial metal polishes use abrasives to make surfaces smooth and reflective, and household polishes control tarnish and clean. Gloss and protection are provided by shoe polishes, which are either self‐polishing liquids, emulsion creams, or solvent pastes that differ from paste furniture polishes in dye and wax content. Shoe creams are emulsions of waxes, solvents, and water. Health, safety, and environmental issues include toxicity, slipperiness, and volatile organic compound levels.
Fluorine‐Containing Polymers, Poly(Fluorosilicones)
Authors: Bajzer William X. , Kim Yung K. 
Published: July 2004

Abstract
Poly(fluorosilicones) are siloxane polymers with fluorinated organic substituents bonded to silicon. The combination of fluoroorganic and siloxane properties into one material has many unique applications. The monomer and polymer preparations are reviewed for the manufacture of poly(3,3,3‐trifluoropropyl)methylsiloxane and related poly(fluorosilicones). The polymers and their materials' application properties are discussed with a correlation to chemical structure and stability. The processing, compounding, and curing of the poly(fluorosilicones) into fluids, sealants, rubber, and related applications are described, along with information on safe handling characteristics. Specific examples of applications are covered. An estimation of global capacity is given along with a perspective on market aspects.
Polycarbonates
Authors: Brunelle Daniel J. 
Published: July 2004

AbstractPolycarbonates are an unusual and extremely useful class of polymers. The vast majority of polycarbonates are based on bisphenol A (BPA) and sold under the trade names Lexan, Makrolon, Calibre, and Panlite. BPA polycarbonates having high glass‐transition temperatures are widely regarded for optical clarity and exceptional impact resistance and ductility at room temperature and below. Other properties such as modulus, dielectric strength, or tensile strength are comparable to other amorphous thermoplastics at similar temperatures below their respective glass‐transition temperatures. Polycarbonates are prepared commercially by two processes: Schotten–Baumann reaction of phosgene and an aromatic diol in an amine‐catalyzed interfacial condensation reaction, or via base‐catalyzed transesterification of a bisphenol with a monomeric carbonate such as diphenyl carbonate. Important products are also based on polycarbonates in blends with other polymers, copolymers, branched resins, flame‐retardant compositions, foams, and other materials. Polycarbonate, produced globally, has been the object of research studies, owing to its widespread utility and unusual properties. This article summarizes the preparation, properties, and utility of polycarbonates.
Fluorine‐Containing Polymers, Polytetrafluoroethylene
Authors: Gangal Subhash V. 
Published: July 2004

AbstractPolytetrafluoroethylene (PTFE) has a unique position in the plastics industry because of its chemical inertness, heat resistance, excellent electrical insulation properties, and low coefficient of friction in a wide temperature range. This white to translucent solid polymer has an extremely high molecular weight in the 106–107range. It is a highly crystalline polymer and has a crystalline melting point, and its high thermal stability is due to the strong carbon‐fluorine bond, making PTFE a very useful high temperature polymer.Commercial PTFE is manufactured by two different polymerization processes that result in two different types of chemically identical polymers. Suspension polymerization produces a granular resin, and emulsion polymerization is used to produce coagulated dispersion or stabilized dispersion. Because of its high molecular weight, PTFE melt does not flow and cannot be fabricated by conventional techniques. The suspension polymerized PTFE is usually fabricated by modified metallurgy techniques. Emulsion polymerized, coagulated PTFE is processed by a cold extrusion process; the stabilized dispersions are processed according to latex processing techniques.