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  • 1
    Electronic Resource
    Electronic Resource
    Preparation and gas permeability of polymer blend membranes of polystyrene and poly[1,1,1-tris(trimethylsiloxy)methacrylate propylsilane] (1982)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 27 (1982), S. 2025-2032 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    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: The gas permeability of O2 and CO2 was sutidied for various polymer blend membranes of polystyrene (PSt) and poly[1,1,1-tris(trimethylsiloxy)methacrylate propylsilane (PTMPS). In order to improve the compatibility of these polymer blends, the effect of addition of the graft copolymer was also investigated. The gas permeability of various composition polymer-blend membranes increases rapidly with an increasing content of PTMPS in the polymer blend. In the polymer blend membranes containing the graft copolymer, the gas permeability decreases with an increase in the graft copolymer content and then reaches a nearly constant value, when the PTMPS content remains constant. This result is attributed to a decrease in interstices at phase boundaries, owing to improvement in compatibility of the component polymers. This method of membrane preparation is very useful for making membranes with required properties.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1982.070270615
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  • 2
    Electronic Resource
    Electronic Resource
    Monitoring of spatial expression of firefly luciferase in transformed zebrafish (1995)
    New York : Wiley-Blackwell
    Journal of Bioluminescence and Chemiluminescence 10 (1995), S. 271-275 
    Details
    ISSN: 0884-3996
    Keywords: firefly luciferase ; zebrafish transformation ; image analysis ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: The firefly luciferase gene attached to the cytomegalovirus promoter was transferred into zebrafish (Brachydanio rerio) by microinjection of fertilized eggs. Light emission could be monitored in vivo in eggs and throughout the early development of the fish by low-light video-image analysis. Gene expression was transient in most of the cases lasting for about 2 weeks. This gene cassette proved to be a very convenient and nondestructive transformation marker and the firefly luciferase gene appears to be a powerful tool for real-time imaging of tissue-specific gene expression in transgenic fish.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bio.1170100503
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  • 3
    Electronic Resource
    Electronic Resource
    The kinetics of heterogeneous mutual radiation grafting (1966)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 95 (1966), S. 106-116 
    Details
    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: Die in heterogenen Systemen durch γ-Bestrahlung gestarteten Pfropfungsreaktionen zeigen oft ähnliche Zeitabhängigkeiten. Nach anfänglicher Selbstbeschleunigung erreicht die Polymerisationsgeschwindigkeit ein Maximum, um dann zu einem tieferen, konstanten Wert abzusinken. Eine derartige Umsatzkurve wurde bei der Pfropfung von Styrol auf Wolle gefunden. Eine befriedigende Begründung für diese spezifische Zeitabhängigkeit der Pfropfungsreaktion wurde bisher trotz zahlreicher kinetischer Behandlungen nicht gegeben. Die in vorliegender Arbeit gebrachte kinetische Behandlung gründet auf der Annahme, daß während der Pfropfungsreaktion die Menge an freien Radikalen stetig zunimmt, wodurch im gequollenen Mutterpolymeren eine Verarmung an Monomerem eintritt, die schließlich zu einer diffusionsbestimmten Pfropfungsgeschwindigkeit führt. Ein solcher Mechanismus ergibt eine Zeitkurve mit einem Maximum der Pfropfungsgeschwindigkeit, wie auch experimentell gefunden wurde. Für die beiden extremen Bereiche der Pfropfungsreaktion wurden beim System Wolle-Styrol die nötigen kinetischen Parameter abgeschätzt und durch Iteration verbessert. Eine gute Übereinstimmung zwischen experimentellen und berechneten Pfropfungsgeschwindigkeiten wurde erhalten.
    Notes: The grafting-time curves of heterogeneous mutual radiation grafting systems are often of the same type. There is a small auto-accelerative period after which the rate rises to a maximum and then levels off to a steady, lower rate. The grafting of styrene to wool fibers is shown to give this type of conversion curve. The reasons for this particular rate-time behavior have not been successfully explained although a number of kinetic treatments have been presented. A kinetic treatment is presented in this paper which postulates that the radical content continues to build up during the grafting process, leading to the gradual depletion of monomer in the substrate polymer and a final diffusion-controlled rate of grafting. This situation leads to the maximum rate type of grafting-time curve actually found. The necessary kinetic parameters have been estimated for the two extreme portions of the grafting curve in the case of the wool-styrene system and further approximated by trial and error. Good agreement between the calculated and experimental rates of grafting was obtained.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1966.020950108
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  • 4
    Electronic Resource
    Electronic Resource
    Radiation-induced emulsion polymerization of vinyl acetate and styrene (1969)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 13 (1969), S. 1175-1189 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    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: Studies have been made of the γ-induced emulsion polymerization of styrene and comparisons made with chemically initiated emulsion polymerization. The polymerization proceeded smoothly to high conversions at 0 and 60°C, the reaction showing a high G (monomer) value. Complete conversions were obtained with total doses of less than 0.05 Mrad. In accordance with the behavior expected of systems having a constant rate of initiation, the molecular weight was found to decrease with decreasing temperature. The molecular weight and particle size distributions were narrower than those obtained in chemically initiated emulsion polymerizations at the same temperature. The radiation-induced emulsion polymerization of vinyl acetate proceeded smoothly at temperatures in the range 0-50°C to give polymers of much higher molecular weight than these obtained from chemically initiated polymerizations at the same temperature. Complete conversion was attained after a dose of 0.02 Mrad for latices approaching 50% solids. The elimination of ionic endgroups in the poly(vinyl acetate) radicals tends to drive the polymerization from the aqueous phase, resulting in faster rates and higher molecular weights than are obtained from chemically initiated systems. Rates of polymerization were found to be independent of temperature and the molecular weight of the polymer to be independent of dose rate. Latices of poly(vinyl acetate) of high solids content were evaluated for latex and film properties and found to have improvements over commercially available samples in both areas, especially in clarity of film and scrub resistance. A number of acrylate and maleate esters were copolymerized with vinyl acetate in a radiation-initiated emulsion system. High molecular weight copolymers were produced after low dose.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1969.070130607
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  • 5
    Electronic Resource
    Electronic Resource
    Radiation grafting of vinyl monomers to wool. Part I (1965)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A: General Papers 3 (1965), S. 3763-3779 
    Details
    ISSN: 0449-2951
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A number of vinyl monomers have been grafted to wool by using the mutual radiation technique. Styrene has been studied in considerable detail in dioxane solution; water or methanol was found to be necessary for successful grafting. It is believed that these function as swelling agents, enabling the monomer to diffuse to the active centers created in the wool by the radiation. The rate of grafting always went through a maximum and then leveled off to a slower rate. This is believed to be due to the slow build-up of the radical population, leading eventually to a diffusion-controlled rate of grafting. Considerable post-polymerization grafting was found to take place. Acrylonitrile and a number of allyl monomers were also successfully grafted to wool by the mutual radiation method in dimethylformamide solution. Again water or methanol was found to be necessary; the grafting rate leveled off close to zero at a degree of grafting depending on the amount of swelling agent present.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1965.100031108
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