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  • 1
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: High-melting paraffin waxes (melting range about 131 °C., molecular weight up to 7000) are synthesized by feeding CO into a suspension of finely divided metallic Ruthenium in H2O at pressures from 75 to 200 at and temperatures from 150 to 260 °C. Byproducts are CO2 and small amounts of CH4 and H2. A CO-conversion up to 100% may be achieved.In this single step synthesis technique water is simultaneously reactant, suspension liquid, heat transfer medium as well as cooling medium by vaporization.The kinetics are of the type of closed cycle consecutive reactions. The reaction velocity is influenced under certain conditions by the mass transfer of CO from gas to liquid phase. The reaction mechanism probably consists of alternating steps of condensation and hydrogenation, involving intermediate chemisorption complexes at the surface of the catalyst, which presumably are similar to hydrocarbonyls.
    Notes: Leitet man CO bei Drucken von 75 bis 200 atü und Temperaturen von 150 bis 260 °C durch eine wäßrige Suspension feinverteilten metallischen Rutheniums, so bilden sich hochschmelzende Paraffinkohlenwasserstoffe vom Schmelzbereich bis zu 131 °C und Molekulargewichten bis zu 7000. Als Nebenprodukt tritt CO2 mit geringen Mengen von CH4 und H2 auf. Es werden CO-Umsätze bis zu 100% erreicht.In dieser verfahrenstechnisch einstufigen Synthese ist das Wasser gleichzeitig Reaktand, Suspensionsträger, Wärmeübertragungsmedium und durch Verdampfung direkt wirkendes Kühlmittel.Kinetisch liegt eine geschlossene Folge vor. Die Reaktionsgeschwindigkeit wird bereichsweise von der Stoffübergangsgeschwindigkeit des CO von der Gasphase in die flüssige Phase beeinflußt. Der Reaktionsmechanismus umfaßt wahrscheinlich alternierende Kondensations-und Hydrierungsschritte, die über vermutlich carbonylwasserstoffartige Chemisorptions-Komplexe an der Oberfläche des Katalysators verlaufen.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 29 (1989), S. 954-959 
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: In this paper we describe the synthesis, characterization, and lithographic evaluations of novel positive photoresists based on hydroxy polyimides and polyamides containing 6-F linking groups. The polymers were synthesized using solution condensation techniques and characterized using solution viscosity, GPC, FTIR, NMR, UV, TGA, and DSC. Tg's of these polymers range from 250 to 300°C. Both polyimides and polyamides are soluble in a variety of solvents commonly utilized for photoresist applications. When formulated with diazonaphthoquinone sensitizers, these polymers provide an improved high-temperature resistant, aqueous base developable positive photoresist system with good photospeed, contrast, and resolution characteristics. High resolution relief images were obtained which are comparable to 1300 Series AZ type photoresists. No thermal deformation, loss in resolution or defects were noticed when relief patterns were annealed to 250°C. Additionally, the hydroxy polyamide based resists, when thermally annealed to 300°C, provide a photoresist system with even higher thermal stability (400 to 450°C) and excellent resistance to solvents. Also, the photoresist formulations have excellent storage stability at room temperature and can be processed like conventional positive photoresists using broad band UV radiation sources.
    Additional Material: 7 Ill.
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 14 (1881), S. 1985-1999 
    ISSN: 0365-9496
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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