bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acrylonitrile Polymers, Survey and SAN
Authors: Ball Lawrence E. , Curatolo Benedict S. 
Published: August 2004

AbstractAcrylonitrile has found its way into a great variety of polymeric compositions based on its polar nature and reactivity. Some of these areas include adhesives and binders, antioxidants, medicines, dyes, electrical insulations, emulsifying agents, graphic arts materials, insecticides, leather, paper, plasticizers, soil‐modifying agents, solvents, surface coatings, textile treatments, viscosity modifiers, azeotropic distillations, artificial organs, lubricants, asphalt additives, water‐soluble polymers, hollow spheres, cross‐linking agents, and catalyst treatments. Styrene–acrylonitrile (SAN) resins possess many physical properties desired for thermoplastic applications. They are characteristically hard, rigid, and dimensionally stable with load bearing capabilities. Modifiers may include uv stabilizers, flow and processing aids, and reinforcing agents. SAN resins show considerable resistance to solvents and are insoluble in carbon tetrachloride, ethyl alcohol, gasoline, and hydrocarbon solvents. Polar solvents such as acetone, chloroform, and pyridine will dissolve SAN. The properties of SAN are significantly altered by water absorption. Commercially, SAN is manufactured by three processes: emulsion, suspension, and continuous bulk. Acrylonitrile copolymerizes readily with many electron‐donor monomers other than styrene. Hundreds of acrylonitrile copolymers have been reported. Copolymers of acrylonitrile and methyl acrylate and terpolymers of acrylonitrile, styrene, and methyl methacrylate are used as barrier polymers. Environmentally degradable polymers are useful in packaging. The largest portion of SAN (80%) is incorporated into ABS resins, and their markets are inexorably joined. SAN resins themselves appear to pose few health problems, and they have been approved by the FDA for food packaging use.
Carbides, Survey
Authors: Oyama S. Ted , Kieffer Richard 
Published: August 2004

AbstractCarbon reacts with many elements of the Periodic Table to form a diverse group of compounds known as carbides, some of which are extremely important in technology. For example, calcium carbide, CaC2, is a source of acetylene; silicon carbide, SiC, and boron carbide, B4C, are used as abrasives; tungsten carbide, WC, titanium carbide, TiC, and tantalum (niobium) carbide, TaC(NbC), find use as structural materials at extremely high temperatures or in corrosive atmospheres. Cementite, Fe3C, and the multimetallic complexes (Co,W)6C, (Cr,Fe,Mo)23C6, and (Cr,Fe)7C3are the components in tool steels and Stellite‐type alloys responsible for their hardness, wear resistance, and excellent cutting performance. There are also emerging applications of these materials as catalysts. Binary compounds of carbon are divided into four main groups: the salt‐like, metallic, diamond‐like, and volatile compounds of carbon. The nature of the bonding is correspondingly of ionic, metallic, semiconductor, or covalent character, but these divisions are not rigid and there are a number of transitional cases. A number of compounds, although containing carbon, fit only marginally in the category of carbides. This includes the acetylides and the alkali metal–graphite compounds, the coordination and organometallic compounds, ML. Carbides are generally prepared by the direct reaction of carbon with metals or metal‐like materials at elevated temperatures. Their most outstanding properties are extreme hardness and physical strength combined with high temperature stability.
Alcohols, Higher Aliphatic, Survey and Natural Alcohols Manufacture
Authors: Peters Richard A. 
Published: August 2004

AbstractThe monohydric aliphatic alcohols of six or more carbon atoms are generally referred to as higher alcohols. Historically, the higher alcohols were derived from natural fats, oils, and waxes and were called fatty alcohols, but now similar alcohols are widely available from synthetic processes using petrochemical feedstocks. Although the natural and synthetic alcohols are used interchangeably for many applications, for some applications the distinction still remains. The detergent range alcohols are used mainly as sulfate, ethoxy, and ethoxysulfate derivatives in a wide variety of detergent and surfactant applications. Most higher alcohols of commercial importance are primary alcohols; secondary alcohols have more limited specialty uses. Typical reactions of the higher alcohols include esterification, sulfation, etherification, halogenation, dehydration, oxidation, and amination. In the United States, most detergent range alcohol production is by synthetic processes. Most manufacturers sell a portion of their alcohol product on the merchant market, retaining a portion for internal use, typically for the manufacture of plasticizers. The higher alcohols are among the less toxic of commonly used chemicals. Fatty alcohols are produced by hydrogenolysis of methyl esters or fatty acids in the presence of a heterogeneous catalyst. There are three principal hydrogenolysis processes in worldwide use. Each process typically uses a copper chromite or copper‐zinc catalyst that is modified to meet the needs of the individual producer. The detergent range alcohols and their derivatives have a wide variety of uses in consumer and industrial products. The major use is as surfactants in detergents and cleaning products. They also are used extensively in cosmetics and pharmaceuticals. The plasticizer range alcohols are utilized primarily in plasticizers, but they also have a wide range of other uses.
Thermoplastic Elastomers
Authors: Holden Geoffrey 
Published: August 2004

AbstractThermoplastic elastomers have many of the physical properties of vulcanized rubbers but can be processed as thermoplastics. This unique behavior has opened a new field of polymer science and technology. Since their commercial introduction in the 1960s, thermoplastic elastomers have become a significant part of the polymer industry. They are used in applications as diverse as adhesives, footwear, medical devices, automobile parts, and asphalt modification. Many of them are block copolymers with alternating hard and soft segments. The thermoplastic elastomers with polystyrene hard segments are the larget group and probably the most versatile; they can be produced over a wide range of hardness values and applied either in the molten state or from solution. Other examples are block copolymers with elastomers, either vulcanized or unvulcanized, in which the two components are intimately mixed together, but in most cases still remain as separate phases. Thermoplastic elastomers of this type are generally used as replacements for vulcanized rubbers. This article reviews the synthesis, morphology, structure‐property relationships, and commercial applications of thermoplastic elastomers of all types.
Tungsten and Tungsten Alloys
Authors: Penrice Thomas W. 
Published: August 2004

AbstractTungsten, discovered in 1755 and produced as a metal in 1783, is notable for having a very low vapor pressure, the highest melting point of any metal, and the highest tensile strength of any metal above 1650°C. It has been used formerly in the manufacture of high speed steels and as a metal filament in electric lamps, where it was fabricated by powder metallurgy using the Coolidge process. The largest modern application is in the manufacture of cemented carbide cutting tools. Tungsten is rated as a strategic material in the U.S. economy.Tungsten occurs in a number of mineral forms, the most important being scheelite and wolframite. The beneficiation and hydrometallurgy are described, together with the principal intermediate compounds used to make the metal powder by hydrogen reduction. Technically it is possible to process compacted powder by arc or electron‐beam melting, but commercially the power metallurgy process of compaction, sintering, and working is used exclusively.The largest reserves of ores occur in China, which has, in more recent years, become the principal source of supply not only for ores but for metal powder and intermediates at prices that have caused most U.S. mines to be closed. About 65% of tungsten usage is as tungsten carbide in cutting and mining tools. The instability of the market as well as economic and environmental factors have favored development of recycling processes. Used cutting tools can be treated with molten zinc and both are recovered tungsten carbide and cobalt binder as mixed powders after vacuum‐distilling off the zinc. It is estimated that 25% of cutting tools are recycled in this way in the United States.Tungsten alloyed with nickel and iron is used for a range of high density compositions that find applications as counterweights in aircraft, as armor‐piercing penetrators, and for collimators and shielding in x‐ray machines. These alloys are characterized by high density and high modulus, which make them suitable for use in critical dynamic structures. Tungsten forms only a few alloys; tungsten–rhenium is important for thermocouples and as a tough lamp filament alloy. Insoluble tungsten has relatively low toxicity, but aerosols with cobalt and with impurities found in mining can have some effect and require controls of exposure level.
Tungsten Compounds
Authors: Penrice Thomas W. 
Published: August 2004

AbstractTungsten combines with many other elements to form simple stable compounds. It readily polymerizes but the chemistry of aqueous solutions is very complex. This is exemplified by the large number of polytungstates. The chemical uses of tungsten have increased substantially in more recent years.The hexacarbonyl has potential as a lubricant additive and as a dye and pigment. The halides are useful as a starting materials in the chemical vapor deposition of tungsten. The oxides are important intermediate products in the stepwise reduction in hydrogen to the metal. Tungsten bronzes constitute a series of well‐defined nonstoichiometric compounds. The sodium tungsten bronzes are interesting not only for their intense color range but exhibit both positive and negative coefficient of resistance as the sodium:tungsten ratio changes. Sodium tungsten bronzes help the catalytic oxidation of carbon monoxide and reformer gas in fuel cells.The tungstates are an important class of materials. The metatungstates are important starting materials for production of tungsten catalysts because of the high solubility in water. Ammonium paratungstate is the intermediate material of choice between chemical recovery from ores and the reduction to tungsten metal. The interstitial compounds, particularly with carbon, represent the largest application for tungsten in cemented carbides. Tungsten compounds, especially the oxides, sulphides, and heteropoly complexes, form stable catalysts for a variety of chemical processes in the petroleum industry and in chemical synthesis. Other uses include fireproofing of textiles, as additives in lubricants and antifreeze solutions, in inks and dyes, as phosphors in fluorescent lights, and for improvement of conductivity of tin oxide coatings on aircraft windows. Because soluble tungsten compounds show varying degrees of toxicity, exposures in the workplace are regulated.
Supercritical water oxidation of a carbon particle by Schlieren photography
Authors: Sugiyama Masakazu , Tagawa Sumiko , Ohmura Hisao , Koda Seiichiro 
Published: August 2004

AbstractThe flow pattern around a carbon particle (∼ 3.5 mm in diameter) during the supercritical water oxidation (SCWO) process (25 MPa, 723 K, 3.6 wt % O2 concentration) was visualized for the first time by the use of Schlieren optics and a SCWO reactor equipped with transparent sapphire windows. To link Schlieren images with flow fields, computational fluid dynamics (CFD) simulations were executed, assuming temperature‐dependent density of supercritical water and heat of a surface reaction, and then the obtained density fields around the particle were numerically converted to Schlieren images. Numerically obtained Schlieren images agreed well with observed images, confirming that the CFD simulation was able to predict the flow field in SCWO processes. Such a combined approach of CFD and flow visualization revealed that, in SCWO of solid substances with a fast reaction rate, the heat of surface reaction increased the temperature of the fluid and induced an upward flow from the particle with higher fluid temperature than that of the surroundings. Such flow can increase reaction rates by enhancing the mass transfer of O2 to solids. Therefore, a flow field in SCWO is an important factor controlling the progress of reaction and it can be reasonably predicted by CFD simulations. © 2004 American Institute of Chemical Engineers AIChE J, 50: 2082–2089, 2004
Clinicopathological correlates in frontotemporal dementia
Authors: Hodges John R. , Davies R. Rhys , Xuereb John H. , Casey Barney , Broe Melissa , Bak Thomas H. , Kril Jillian J. , Halliday Glenda M. 
Published: August 2004

AbstractThe term frontotemporal dementia (FTD) encompasses a range of clinical syndromes that are believed not to map reliably onto the spectrum of recognized pathologies. This study reexamines the relationships between clinical and pathological subtypes of FTD in a large series from two centers (n = 61). Clinical subtypes defined were behavioral variant FTD (n = 26), language variants (semantic dementia, n = 9; and progressive nonfluent aphasia, n = 8), and motor variants (corticobasal degeneration, n = 9; and motor neuron disease, n = 9), although most cases presented with a combination of behavioral and language problems. Unexpectedly, some behavioral cases (n = 5) had marked amnesia at presentation. The pathological subtypes were those with tau‐immunopositive inclusions (with Pick bodies, n = 20; or without, n = 11), those with ubiquitin immunopositive inclusions (n = 16), and those lacking distinctive histology (n = 14). Behavioral symptoms and semantic dementia were associated with a range of pathologies. In contrast, other clinical phenotypes had relatively uniform underlying pathologies: motor neuron disease predicted ubiquitinated inclusions, parkinsonism and apraxia predicted corticobasal pathology, and nonfluent aphasia predicted Pick bodies. Therefore, the pathological substrate can be predicted in a significant proportion of FTD patients, which has important implications for studies targeting mechanistic treatments. Ann Neurol 2004
Hemispheric mediation of spatial attention: Pseudoneglect after callosal stroke
Authors: Wolk David A. , Coslett H. Branch 
Published: August 2004

AbstractStudy of patients with callosal lesions can provide insight into the mediation of spatial attention‐intention by each hemisphere. Two patients with anterior callosal strokes bisected lines to the left of midline with the left hand and to the right of midline with the right in both a visual and tactile bisection task. The patients demonstrated a similar pattern of performance on pointing to body‐midline in space. These results are consistent with the notion that each hemisphere supports spatial attention‐intention toward contralateral space and that the corpus callosum is critical in the integration of such information. Ann Neurol 2004
Crystallographic report: Di(p‐fluorobenzyl)tin bis(N,N‐dimethyldithiocarbamate)
Authors: Yin Han‐Dong , Wang Chuan‐Hua 
Published: August 2004

AbstractThe tin atom in (p–FC6H4CH2)2(S2CNMe)2 is in a skewed‐trapezoidal bipyramidal geometry defined by two sets of sulfur donors derived from the dithiocarbamate ligands and two carbon atoms from the tin‐bound p‐fluorobenzyl substituents; CSnC is 129.2(2)°. Copyright © 2004 John Wiley & Sons, Ltd.
Ring‐opening metathesis polymerization of cyclododecene using an electrochemically reduced tungsten‐based catalyst
Authors: Karabulut Solmaz , Çetinkaya Sevil , Düz Bülent , İmamoǧlu Yavuz 
Published: August 2004

AbstractThe ring‐opening metathesis polymerization of cyclododecene using an electrochemically reduced tungsten‐based catalyst (WCl6e−AlCH2Cl2) is described. In addition, the influence of reaction conditions on the polymerization yield was determined. The resulting polymer has been characterized by NMR, IR, gel permeation chromatography and differential scanning calorimetry. The glass transition temperature and melting point of the polydodecenamer are 19.6°C and 70.0°C respectively. Furthermore, cyclododecene has been polymerized into a low‐molecular‐weight polymer (12.0 × 103) with a polydispersity of 2.06 in high yields (94%). IR and NMR analysis indicate that the polydodecenamer has a high trans content (60%). Copyright © 2004 John Wiley & Sons, Ltd.
Crystallographic report: Crystal structure of tris(2,6‐di‐tert‐butyl‐4‐methylphenolato‐O) (tetrahydrofuran‐O) erbium toluene solvate
Authors: Xu Xiaoping , Yao Yingming , Zhang Yong , Shen Qi 
Published: August 2004

AbstractA low‐coordinate aryloxo erbium complex, [(ArO)3Er(THF)](MePh), has been synthesized by the reaction of anhydrous ErCl3 with three equivalents of NaOAr in tetrahydrofuran. The central erbium atom is coordinated by three oxygen atoms of the aryloxo ligands and one oxygen atom of the tetrahydrofuran molecule, resulting in a distorted tetrahedron. Copyright © 2004 John Wiley & Sons, Ltd.
Crystallographic report: Bis[tris(morpholindithiocarbamato)bismuth(III)]
Authors: Yin Han‐Dong , Wang Chuan‐Hua 
Published: August 2004

AbstractThe dimeric and centrosymmetric structure of {Bi[S2CN(CH2CH2)2O]3}2 features chelating dithiocarbamate ligands and intermolecular BiS interactions, so that a distorted pentagonal bipyramidal S7 coordination geometry results. Copyright © 2004 John Wiley & Sons, Ltd.
Crystallographic report: Diisopropylammonium [3‐(2‐thienyl)‐2‐sulfanylpropenoato]triphenylstannate
Authors: Casas José S. , Couce Marıa D. , Sánchez Agustín , Sordo José , Varela José M. , Vázquez‐López Ezequiel M. 
Published: August 2004

AbstractThe title compound comprises trigonal bipyramidal SnPh3(tspa) anions and iPr2NH2 cations linked into centrosymmetric dimers by NH·O hydrogen bonds. Copyright © 2004 John Wiley & Sons, Ltd.
Crystallographic report: A two‐dimensional zinc phosphate framework: [H3N(CH2)3NH3]0.5[Zn2(PO4)(HPO4)]
Authors: Wang Lei , Li Guanghua , Ma Jingjing , Feng Shouhua 
Published: August 2004

AbstractThe two‐dimensional zinc phosphate [H3N(CH2)3NH3]0.5[Zn2(PO4)(HPO4)], has been synthesized hydrothermally using 1,3‐diaminopropane as the template. Its structure contains an inorganic framework with three‐, four‐, or six‐membered rings, built from PO4, PO3(OH) and ZnO4 tetrahedral moieties sharing vertexes. The protonated 1,3‐diaminopropane molecules interact with the framework through hydrogen bonds. Copyright © 2004 John Wiley & Sons, Ltd.
Crystallographic report: [(η5‐C5H5)Fe(CO)2]2Ga3Cl3(OSiMe2OSiMe2O)2: a diiron complex of a tetracyclic trigallasiloxane
Authors: Bunn Natalie R. , Aldridge Simon , Jones Cameron 
Published: August 2004

AbstractThe structure of the penta‐metallic diiron trigallasiloxane, [(η5‐C5H5)Fe(CO)2]2Ga3Cl3(OSiMe2 OSiMe2O)2, reveals two distinct gallium coordination environments and FeGa bond lengths (2.3258(6) Å), consistent with bonding of the iron centres to four‐coordinate gallyl ligands. Copyright © 2004 John Wiley & Sons, Ltd.
Crystallographic report: 6‐Mercaptopurinate complex of tribenzyltin(IV), (PhCH2)3Sn(C5H3N4S)Sn(PhCH2)3OMe
Authors: Ma Chunlin , Sun Jiafeng 
Published: August 2004

AbstractThe title complex displays a binuclear structure in which the geometries of tin atoms are different: one is cis‐trigonal bipyramidal (with a C3NS donor set) and the other is trans‐trigonal bipyramidal (C3NO). Copyright © 2004 John Wiley & Sons, Ltd.
Crystallographic report: Bis[N,N‐dimethyl‐N′‐(pyrid‐2‐ylmethyl)‐ethylenediamine]zinc(II) diperchlorate
Authors: Bian He‐Dong , Yu Qing , Liang Hong , Yan Shi‐Ping , Liao Dai‐Zheng , Cheng Peng , Jiang Zong‐Hui 
Published: August 2004

AbstractThe zinc(II) atom in the centrosymmetric complex is in a distorted N6 octahedral geometry defined by two tridentate ligands. Copyright © 2004 John Wiley & Sons, Ltd.
Crystallographic report: Dibenzyltin(IV) bis(N,N‐dibenzyldithiocarbamate)
Authors: Yin Han‐Dong , Xue Sheng‐Cai 
Published: August 2004

AbstractA distorted octahedron C2S4 geometry is found for the tin atom in the title compound; CSnC is 136.61(19)°. Copyright © 2004 John Wiley & Sons, Ltd.
Studies on the catalysis of the reaction of organotin phenoxides with bis(2,2,2‐trichloroethyl) azodicarboxylate by lithium perchlorate
Authors: Kinart Wojciech J. , Kinart Cezary M. , Tran Quang T. , Oszczȩda Rafał , Nazarski Ryszard B. 
Published: August 2004

AbstractOrganotin phenoxides, which are distinctly more active than the corresponding phenols, react at room temperature with bis(2,2,2‐trichloroethyl) azodicarboxylate to produce para‐substituted phenolic hydrazides in high yields. Copyright © 2004 John Wiley & Sons, Ltd.
Synthesis and characterization of some penicillins modified with germanium‐containing moieties
Authors: Imafuku Yoko , Takeuchi Yoshito 
Published: August 2004

AbstractPenicillin derivatives, penicillin G (1), penicillin V (2) and ampicillin (3), were modified with germanium‐containing moieties and their structures were confirmed based on NMR spectroscopy and MALDI‐TOF. Their antibacterial ability was tested. None of these exhibited activity stronger than the parent penicillins. Copyright © 2004 John Wiley & Sons, Ltd.
Modification of low energy polymer surfaces by immobilization of fluorinated carboxylates with zirconium‐based coupling agents
Authors: Textor Torsten , Schollmeyer Hauke , Bahners Thomas , Schollmeyer Eckhard 
Published: August 2004

AbstractAfter the photochemical generation of carboxylates onto surfaces of several aromatic polymers, complexes based on zirconyl‐(IV)‐acetylacetonate are immobilized. These zirconium compounds tend to form strong bonds to carboxylates. Subsequently, zirconium modified surfaces are treated with solutions of a highly fluorinated lithium carboxylate yielding oil‐ and water‐repellent surfaces. It is shown that combined with excimer‐UV‐laser‐induced micro structuring, the treatments lead to super‐repellent surfaces showing contact angles of water up to 160°. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 789–795, 2004
Influence of ammonium polyphosphate on the mechanism of thermal degradation of an acrylic binder resin
Authors: Drevelle Christophe , Duquesne Sophie , Le Bras Michel , Lefebvre Jérôme , Delobel René , Castrovinci Andrea , Magniez Carole , Vouters Moïse 
Published: August 2004

AbstractThe thermal behavior of an acrylic binder resin used in back coatings for textile applications was studied. The influence of the crystalline form of the fire‐retardant additive on the thermal behavior was investigated. This resin formed a carbon char during its thermal degradation, so it may be assumed that it acts as a charring agent in intumescent systems with ammonium polyphosphate (APP) as the acid source. Thermogravimetric and spectroscopic analyses of acrylic binder resin/APP mixtures demonstrated the influence of the crystalline form of APP. The degradation mechanism of the binder resin could be described by ring closure and the formation of unsaturations. APP leads to the formation of a phosphocarbon structure that is thermally stable, whatever the crystalline form was of APP. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 717–729, 2004