Zehentmaier S.,Dyneon GmbH
Gummi, Fasern, Kunststoffe | Year: 2015
More than 70 years after the discovery of polytetrafluoroethylene (PTFE), fluoropolymers have become well-established as an extremely useful material family in a variety of technical applications. In addition to PTFE itself, which cannot be processed with many of the conventional methods, utilised in plastics technology, a whole series of fluorothermoplastics that are flexible to handle has gained a place in everyday life. In film applications they stand out among other things by exceptional resistance to tear propagation and chemical resistance. Most visible for many consumers are fluorothermoplastic films in outdoor applications: PTFE-derived fluorinated plastics such as ethylene-tetrafluoroethylene (ETFE) are used among other things in photovoltaic systems and architecture. Here they convince for example due to their high robustness and self-cleaning properties. Another advantage is the considerably lower weight compared to glass, which enables the design of more filigree load-bearing structures or permits them in the first place. Not least, these weather-resistant films allow the realisation of very courageous and aesthetically pleasing architectural ideas. Also, the problem of heat build-up under transparent fluorothermoplastic roofs can now be solved, thanks to the new, multi-layer optical films.
Fluoroplastic materials for pressure tubes in Flue Gas heat exchangers under corrosive conditions of Flue Gas Desulfurization Plants [Fluorkunststoffe für Druckrohre in Rauchgaswärmetauschern unter korrosiven Bedingungen für die Rauchgasentschwefelung]
Gottschalk-Gaudig G.,Dyneon GmbH |
Broda S.,Heatec Co. |
Adamczyk F.,Babcock Borsig Service GmbH |
Kreilos K.,Babcock Borsig Service GmbH
VGB PowerTech | Year: 2010
Power stations are required to be equipped with Flue Gas Desulfurization Plants since the 1980s. Today's Babcock Borsig Service GmbH (BBS) developed corrosion resistant heat exchanger systems for cooling and re-heating flue gas below the acid dew point already at that time. Field tests performed at the Wilhelmshafen power plant showed corrosion below the coating in the metallic materials used back then for the flue gas cooling tubes. The by far best results were achieved with full plastic tubing. Experiences with a pilot heat exchanger with PTFE heat recovery tubes in the power plant of Witten-Herdecke lead to a raw material redesign of the already planned succession plant Schwandorf CID with PFA heat recovery tubes. Since then, about 30 BBS-designed reference power plants were equipped with PFA cooling tubes. Prior to industrial deployment, the PFA tubing was certified by the TÜV regarding strength-calculation and -evaluation. Not even after more than 60.000 operating hours did the PFA cooling tubes show any changes in their chemical structure. Aside from the development of polymer heat exchangers and their differences to alternative concepts, different types of fluoropolymers will be described, particularly highlighting the differences between PFA and PTFE. Starting with knowledge derived from the long- term utilization of PFA tubing in connection with different fuels and optimized manufacturing processes, a new prospective concept for the tube design for the future is Introduced.
Bottcher T.,Jacobs University Bremen |
Shyshkov O.,Dyneon GmbH |
Bremer M.,Merck KGaA |
Bassil B.S.,Jacobs University Bremen |
Roschenthaler G.-V.,Jacobs University Bremen
Organometallics | Year: 2012
Carbene-stabilized complexes of substituted and unsubstituted phosphorus(V) fluorides were obtained by oxidative addition of 2,2-difluorobis(dialkylamines) to phosphorus(III) halides. Octahedral and hydrolytically stable complexes were obtained in quantitative yields. All compounds were characterized in the solid state by single-crystal X-ray diffraction. © 2011 American Chemical Society.
« VW: 430,046 MY 2016 vehicles in Europe affected by “CO2 issue” | Main | Huawei unveils new fast-charging Li-ion batteries » 3M will supply Plug Power Inc. with membrane electrode assemblies (MEAs) to be used in Plug Power designed proton exchange membrane (PEM) fuel cell stacks under a new strategic supply agreement. Through this strategic supply agreement, fuel cell stacks will be manufactured in Plug Power’s Latham, NY and Spokane, WA facilities to support the $20-billion material handling market. Additionally, this new fuel cell stack technology will be utilized to expand Plug Power’s presence into hydrogen-enabled electric vehicle applications outside of the material handling market. Fuel cell systems using the 3M MEA’s and Plug Power stack design will begin shipments in the fourth quarter of 2015. 3M offers a broad portfolio of solutions for fuel cell construction—for low- and high-temperature applications—including fluoropolymers, membrane materials and advanced ceramics. 3M has applied its expertise in electrochemistry, fluoropolymer membrane, and high throughput manufacturing for advanced fuel cell MEAs. 3M Dyneon Fluoropolymers feature excellent chemical and temperature resistance, weatherability, permeation control and low surface energy— making them highe suited for PEM applications. For example, gaskets made from 3M Dyneon Ultra Low Viscosity Fluoroelastomers cure at low temperatures for seal-in-place solutions. Barrier films can be made from thermoplastics such as 3M Dyneon THV, which imparts oxidative stability; 3M thermoplastics also function as binders for bipolar plate applications. 3M’s fully integrated membrane electrode assembly is based on its catalyst coated membrane (CCM). The CCMs feature integrated, thrifted subgasketed construction, and combine low precious metal loadings with strong performance and durability. 3M researchers have been working for several years on a DOE-funded project to develop a durable, low-cost, robust, high-performance membrane electrode assembly (MEA) for transportation applications that is able to meet or exceed US Department of Energy 2020 MEA targets. Partners in the three-year, $4.6-million project include Johns Hopkins University, Oak Ridge National Laboratory, Lawrence Berkeley National Laboratory, Michigan Technological University, Freudenberg FCCT, Argonne National Laboratory, Los Alamos National Laboratory and GM. The approach 3M took with this advanced MEA research project was to optimize the integration of advanced anode and cathode catalysts, based on 3M’s nanostructured thin film (NSTF) catalyst technology platform, with next generation PFSA PEMs (polymer electrolyte membranes based on perfluorosulfonic acid); gas diffusion media; cathode interfacial layers; and flow fields to improve overall MEA performance, durability, robustness, and cost. Plug Power’s GenKey, provides an all-inclusive package for customers, incorporating GenFuel hydrogen and fueling infrastructure, GenCare aftermarket service and either GenDrive or ReliOn fuel cell systems. GenDrive, a lead-acid battery replacement, is used in electric lift trucks in high-throughput material handling applications. With more than 9,000 GenDrive units deployed with material handling customers, GenDrive has been proven reliable with over 107 million hours of runtime.
Cobos C.J.,National University of La Plata |
Hintzer K.,Dyneon GmbH |
Solter L.,University of Gottingen |
Tellbach E.,University of Gottingen |
And 3 more authors.
Physical Chemistry Chemical Physics | Year: 2015
The thermal dissociation of octafluorocyclobutane, c-C4F8, was studied in shock waves over the range 1150-2300 K by recording UV absorption signals of CF2. It was found that the primary reaction nearly exclusively produces 2 C2F4 which afterwards decomposes to 4 CF2. A primary reaction leading to CF2 + C3F6 is not detected (an upper limit to the yield of the latter channel was found to be about 10 percent). The temperature range of earlier single pulse shock wave experiments was extended. The reaction was shown to be close to its high pressure limit. Combining high and low temperature results leads to a rate constant for the primary dissociation of k1 = 1015.97 exp(-310.5 kJ mol-1/RT) s-1 in the range 630-1330 K, over which k1 varies over nearly 14 orders of magnitude. Calculations of the energetics of the reaction pathway and the rate constants support the conclusions from the experiments. Also they shed light on the role of the 1,4-biradical CF2CF2CF2CF2 as an intermediate of the reaction. © 2015 the Owner Societies.