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Surface Protection (surface + protection)
Selected AbstractsThe use of fire-retardant intumescent mats for fire and heat protection of glass fibre-reinforced polyester composites: Thermal barrier propertiesFIRE AND MATERIALS, Issue 1 2010Everson Kandare Abstract This study investigates the use of integral, hybrid intumescent thermal barriers (mats) to provide surface protection to the core fibre-reinforced polyester composite structural integrity when exposed to a fire or heat source. Glass fibre-reinforced composites protected by intumescent mats/fabrics containing silicate fibres, expandable graphite and in some cases borosilicate glass bounded together by an organic matrix have been evaluated for fire performance under a constant heat flux of 50kW/m2. The effect of insulative fabric thickness as well as chemical composition on the flammability of the resultant hybrid composites is evaluated. Glass fibre-reinforced polyester (GRP) composites without any surface protection have a relatively higher time-to-ignition and peak heat release rate values when compared with core composites protected by insulative fabrics. Thermograms representing the variation of temperature on the reverse side of the hybrid composites with time when exposed to a constant heat flux show that the inclusion of intumescent surface barriers results in retarded temperature increments within the core GRP composites. Copyright © 2009 John Wiley & Sons, Ltd. [source] Microstructure,property,quality-correlated paint design: An LMC-based approachAICHE JOURNAL, Issue 1 2009Jie Xiao Abstract Paint is designed to offer various chemical and physical properties for surface protection, styling, and appearance. Nevertheless, the anticipated quality of the surface coating is frequently unsatisfactory, which is often attributed to paint formulation. As new demands on coating performance continuously emerge, paint formulation design becomes much more challenging than ever. It is recognized that paint design can be significantly improved with the help of advanced computational methods, as they can provide great freedom and control over the investigation of paint formulation through any number of in silico experiments virtually under any application conditions. This article introduces a lattice Monte Carlo based computational methodology for paint formulation design. By this methodology and structural analysis techniques, a variety of correlations among paint material, curing condition, coating microstructure, and coating qualities can be generated, which are critical for the development of superior paint formulations. A comprehensive study on acrylic-melamine-based paint design and analysis demonstrates the methodological efficacy. © 2008 American Institute of Chemical Engineers AIChE J, 2009 [source] Carbocationic Polymerizations for Profit and FunMACROMOLECULAR SYMPOSIA, Issue 1 2004Ralf M. Peetz Abstract This presentation consists of two largely independent parts: The first åfor Profit, part concerns a bird's eye view of recently commercialized carbocationic processes and materials created by these processes in the author's laboratories whose marketing started during the past ,5 years by various companies. These materials/processes include liquid telechelic polyisobutylene (PIB) for architectural sealants, poly(styrene- b -isobutylene- b -styrene) (PSt- b -PIB- b -PSt) triblocks for thermoplastic elastomers, PIB/PSt-based blocks for coating of medical devices, and PIB-based microemulsions for surface protection of painted metal surfaces. It is concluded that in order to enhance and solidify research in polymer synthesis it would behoove the scientific community to pay increased attention to intellectual property protection. Appropriately managed patenting and publishing activities are self-reinforcing and may be quite profitable. The second "for Fun" part concerns a brief review of the design, synthesis and characterization of two novel fully aliphatic star-block copolymers: ,(PIB- b -PNBD)3 and ,(PNBD- b -PIB)3 (where PNBD = polynorbornadiene). The constituent moieties of these star-blocks are identical except their block sequences are reversed. Motivation for the synthesis of ,(PIB- b -PNBD)3, consisting of a low Tg (,-73°C) PIB inner-corona attached to a high Tg (,320°C) PNBD outer corona, was the expectation that this star-block would exhibit thermoplastic elastomer characteristics, and that it could be used in applications where similar polyaromatic-based TPEs cannot be employed (e.g., magnetic signal storage). The other star-block, ,(PNBD- b -PIB)3, comprises the same building blocks with the PIB and PNBD sequences reversed. We found that the secondary chlorine at the PNBD chain end, in conjunction with TiCl4, is able to initiate the polymerization of isobutylene. Details of the carbocationic polymerization of NBD, together with the microstructure of PNBD, will be discussed. [source] Application of thermally sprayed coatings of the type WC/CoCr in reverse osmosis processes for seawater desalinationMATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 11 2008A. Dwars Abstract Seawater desalination based on the reverse osmosis process requires a variety of hydraulic systems. The material concepts of these hydraulic systems are designed to reliably resist the corrosive properties of seawater and brine as well as the tribological loads. Strong tribological loads typically occur during the start-up and shutdown of multi-stage high-pressure pumps. Thermally sprayed coatings can be used to increase the wear resistance and also the tribological properties of bearings. Also in pressure exchangers for energy recovery, high tribological loads occur on the surfaces of rotors which operate with a clearance gap of 40,100 µm. Today, thermally sprayed coatings are used for the surface protection of these rotors. To resist the various tribological loads, the material pairs are optimized for each case. Thermally sprayed coatings with high surface hardness have proven to be particularly successful. A coating system, based on a CoCr matrix, has been developed especially for these applications. [source] Engineering and Design of Wear and Corrosion Resistant PVD Coatings Regarding the Exceptional Properties of Magnesium SubstratesPLASMA PROCESSES AND POLYMERS, Issue S1 2007Holger Hoche Abstract Although magnesium alloys were popular in the first half of the 20th century, the bad corrosion properties prevented their breakthrough in industrial mass production. Since the technology for the production of high purity alloys was introduced in the 1970s, magnesium alloys became more and more in the focus of industrial attention. Today magnesium alloys are state-of-the-art in construction parts in automotive industry. Despite its outstanding properties like good castability, low density and nearly unlimited availability the negative aspects like weak corrosion and wear behaviour still limit the application of magnesiums in industry, due to the need of sufficient surface protection (E. Aghion, B. Bronfin, Mater. Sci. Forum2000, 350,351, 19). Today, plasma electrolytic anodisations are state-of-the-art (H. Haferkamp, "Magnesiumkorrosion,Prozesse, Schutz von Anode und Kathode", in: Moderne Beschichtungsverfahren, F.-W. Bach, T. Duda, Eds., Wiley-VCH, Weinheim 2000, ISBN 3-527-30117-8, 242; M. Thoma, Metalloberfläche1984, 38, 393; T. W. Jelinek, Galvanotechnik2003, 94, 46; A. Kuhn, Galvanotechnik2003, 94, 1114). They provide acceptable corrosion resistance and protect the magnesium from mechanical damage due to their high hardness. On the other hand, their high porosity limits their use in combination with electrochemically noble materials, leading to galvanic corrosion (J. Senf, "Untersuchung und Beschreibung von Magnesiumdruckgusslegierungen unter tribologischer, korrosiver und mechanisch-korrosiver Beanspruchung, Berichte aus der Werkstofftechnik", Shaker Verlag, Germany 2001, ISBN 3-8265-8428-7). In addition, the high surface roughness of the plasma electrolytic anodisations restricts their use in tribological applications, particularly under sliding conditions (H. Hoche, "Grundlegende Untersuchungen zur Entwicklung von PVD-Beschichtungen auf Magnesiumlegierungen im Hinblick auf die Erhöhung der Verschleißbeständigkeit und unter Berücksichtigung des Korrosionsverhaltens", Dissertation, TU-Darmstadt D17, Shaker Verlag, Germany 2004). In order to achieve smooth surfaces with high quality, the PVD technology moves into the centre of interest. Since the 1980s PVD coatings are well established and widely used for different industrial applications, mainly for steel and tool coatings. The authors were the first who carried out serious studies on the development of PVD coatings for magnesium alloys in 1999 (J. Senf, "Untersuchung und Beschreibung von Magnesiumdruckgusslegierungen unter tribologischer, korrosiver und mechanisch-korrosiver Beanspruchung, Berichte aus der Werkstofftechnik", Shaker Verlag, Germany 2001, ISBN 3-8265-8428-7; H. Hoche, "Grundlegende Untersuchungen zur Entwicklung von PVD-Beschichtungen auf Magnesiumlegierungen im Hinblick auf die Erhöhung der Verschleißbeständigkeit und unter Berücksichtigung des Korrosionsverhaltens", Dissertation, TU-Darmstadt D17, Shaker Verlag, Germany 2004). The extensive research activities lead to the recent development of a coating system, which provides both, good wear properties as well as good corrosion behaviour. [source] Schutz und Instandsetzung von Betonbauteilen mit genormten Produkten nach EN 1504BETON- UND STAHLBETONBAU, Issue 10 2006M. Raupach Prof. Dr.-Ing. Die Europäische Normenreihe EN 1504 für Schutz und Instandsetzung von Betonbauteilen steht unmittelbar vor ihrer Fertigstellung. Sie besteht aus 10 Hauptnormen und 62 zugehörigen Europäischen Prüfnormen. Die Hauptnormen EN 1504-2 bis 7 regeln die Produktgruppen Oberflächenschutzsysteme, Mörtel, Klebstoffe für Verstärkungen, Riß- und Hohlraumfüllstoffe, Ankermörtel sowie die Stahlbeschichtungen. Die Prinzipien für den Gebrauch der Produkte sowie die Anwendung der Produkte auf der Baustelle mit zugehöriger Qualitätssicherung sind in den Teilen 9 und 10 enthalten. Ferner ist die Qualitätssicherung der Produkte in Teil 8 geregelt. Somit liegt in Kürze ein umfassendes Normenwerk für Schutz und Instandsetzung von Betonbauteilen vor. Derzeit wird beraten, wie dieses Normenwerk in Deutschland eingeführt wird. Aus verschiedenen Gründen wurde beschlossen, daß die Teile für Planung und Anwendung in Deutschland nicht eingeführt werden, weil mit den bestehenden Richtlinien des DAfStb "Schutz und Instandsetzung von Betonbauwerken" sowie der ZTV-ING langjährig bewehrte Regelwerke vorliegen. Um die Europäisch zukünftig mit CE-Zeichen markierten Produkte für Schutz und Instandsetzung von Betonbauwerken verwenden zu können, wurden für den Oberflächenschutz, die Mörtel, Rißfüllstoffe und die Stahlbeschichtungen inzwischen entsprechende Restnormen (DIN V 18026 bis 18028) erarbeitet, während die Kleber und Ankermörtel wie bisher in Zulassungen geregelt werden. In diesem Beitrag wird beschrieben wie zukünftig in Deutschland Schutz und Instandsetzung von Betonbauteilen mit genormten Produkten nach EN 1504 erfolgen soll. Repair and protection of concrete structures using products according to the standard EN 1504 The European series of standards EN 1504 for protection and repair of concrete structures is actually more or less finished. It consists of 10 main standards and 62 European test standards. The main standards EN 1504-2 to 7 refer to the product classes surface protection systems, mortars, adhesives for strengthening, materials for filling of cracks and voids, anchoring products as well as protection materials for the steel surface. The principles for the use of the products and systems as well as the application of the products on site including quality assurance are regulated in parts 9 and 10. Furthermore the quality assurance for the products is described in part 8. In this way within the next months an extensive set of standards for protection and repair of concrete structures is available. Actually it is discussed, how this set of standards will be introduced in Germany. Due to different reasons it has been decided, that the parts for design and application will not be introduced in Germany, because the existing standards of the DAfStb "Protection and repair of concrete structures" as well as the ZTV-ING have been used successfully for several years. To be able to use the European CE-marked products for protection and repair of concrete structures in future in Germany, for surface protection, mortars, materials for filling of cracks and voids as well as steel coatings in the meantime additional standards (DIN V 18026 to 18028) have been worked out, while the adhesives and anchoring products will be handled via approvals as before. This paper describes, how protection and repair of concrete structures will be carried out in Germany with CE-marked products according to EN 1504. [source] Ocular surface retention time and extensions of TFBUT of a lubricating eye dropACTA OPHTHALMOLOGICA, Issue 2007M IPINAZAR UNDURRAGA Purpose: The tear film in subjects with ocular dryness is often unstable and incapable of maintaining the protective qualities that are intrinsic to its structure and function. Until recently, lubricating eye drops have provided only transient relief from ocular dryness. The purpose of these studies is to determine if a lubricating eye drop, containing PG/PEG/HP-Guar, will extend ocular protection. Methods: To compare the ocular residence time of lubricating eye drops, subjects with dry feeling eyes were administered a solution of Fluoroscein Isothiocyanate-dextran mixed with a the eye drops. The residence time was measured by a scanning fluorometer. To compare TFBUT, subjects with moderately dry feeling eyes were administered a single drop of a lubricating eye drop. After instillation, TFBUT was measured at 0, 5, 10, 15, 20, 30, 45, 60, and 90 minutes. Results: Tear film retention of the PG/PEG/HP-Guar product was significantly greater than a HPMC and a CMC lubricating eye drop. The product containing PG/PEG/HP-Guar was measured in the tear film as much as 37 minutes post instillation, while the HPMC and CMC drops were only 25 and 23 minutes, respectively. The PG/PEG/HP-Guar tear yielded a significantly greater increase in TFBUT from baseline at 45, 60, and 90 minutes post-installation compared to eyes dosed with a CMC/Glycerin drop. Conclusions: Based on these results, it can be postulated that the extended duration of retention observed with the PG/PEG/HP-Guar tear allows the necessary time for restructuring of the unstable tear film into a more stable tear film. This leads to a long-term tear film stabilization and enhancement of TFBUT and ultimately, extended ocular surface protection [source] | |||||||||||||