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  • 1960-1964
  • 1950-1954  (3)
  • 1952  (3)
  • Chemistry  (3)
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  • 1960-1964
  • 1950-1954  (3)
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  • 1
    Electronic Resource
    Electronic Resource
    Redox recipes. VII. A recipe with ferric versenate, hydrazine, and hydroperoxide as activating system (veroxazine recipe)This investigation was carried out under the sponsorship of the Reconstruction Finance Corp., Synthetic Rubber Division, in connection with the U. S. Government Synthetic Rubber Program. (1952)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 9 (1952), S. 343-367 
    Details
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A new initiating system, named the “Veroxazine” system, for the copolymerization of butadiene (75)-styrene (25) is described. Ferric versenate is reduced by hydrazine to the ferrous complex which in turn reacts with hydroperoxide to produce the radicals which initiate polymerization. At 5°C., with 5 parts of K-fatty acid soap, 0.1 part of Diox D, 0.1 part of N2H4·H2SO4, 0.0615 part of sodium hydroxide (to give free hydrazine base from the salt), 0.0005 M ferric iron (equivalent to 0.036 part ferric nitrate nonahydrate per 100 parts monomers), 0.0005 M versene, 1 part of K4P2O7 and 0.3 part sulfole, 70% conversion is reached in 12 hours. The rate of conversion can be varied within wide limits by changing the concentration of ferric iron, versene, or hydrazine. Typical conversion-time data at 5°C. with K-fatty acid soap, 0.1 Diox D, and 1 part of K4P2O7 are summarized below. TextFe(III)VN2H4·H2SO4, partConversion, %124812 hrs.0.005M0.002M0.114254790 - 0.002M0.001M0.111224475 - 0.001M0.0008M0.19193264850.0005M0.0005M0.16162848700.0003M0.0002M0.14101938530.001M0.0005M0.417315292 - 0.001M0.0005M0.215274081 - 0.001M0.0005M0.111213362830.001M0.0005M0.05614274766With a given concentration of ferric iron the maximum rate is found with a molar concentration of versene slightly smaller than that of ferric iron. The excess of ferric iron over versene is kept in aqueous solution as the complex with pyrophosphate. The addition of potassium pyrophosphate up to one part increases the rate of conversion and yields a normal latex free from precoagulation. In the absence of pyrophosphate a viscous latex subject to precoagulation is obtained. The effects of kind and amounts of soap, of free acid or base, of kind and concentration of hydroperoxide, kind and concentration of mercaptan, of oxygen, of methanol, and of shortstops have been investigated. Veroxazine recipes which give from 55 to 70% conversion in 12 hours at -5°C. are described.
    Additional Material: 28 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1952.120090406
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  • 2
    Electronic Resource
    Electronic Resource
    Redox recipes. VIII. A recipe with ferric versenate, sodium sulfide and hydroperoxide as activating system (veroxasulfide recipe)This investigation was carried out under the sponsorship of the Reconstruction Finance Corporation, Synthetic Rubber Division, in connection with the U. S. Government Synthetic Rubber Program. (1952)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 9 (1952), S. 433-452 
    Details
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A new recipe called the Veroxasulfide Recipe is described for the polymerization of butadiene (75)-styrene (25). The initiating system is composed of ferric versenate, sodium sulfide, and a hydroperoxide. With K-fatty acid soap as emulsifier, the use of 0.00728 part of ferric nitrate nonahydrate (corresponding to 10-4 M ferric iron in the aqueous phase), 10-4 M versene, 0.02 part of sodium sulfide, and 0.1 part of Diox D, the following conversions are found at 5°C.: TextTime, hrs.124812Conversion, %816326685The optimum amount of sodium sulfide is 0.02 part (equivalent to 0.062 part of the nonahydrate) but the rate does not depend critically on the amount. The optimum rate is found with approximately 0.00025 M ferric versenate (8.3% in 8 hours at 5°C.) and the rate may be adjusted conveniently by adjustment of the amount of ferric versenate. The presence of a considerable excess of versene over ferric iron does not affect the rate. With less versene than the amount equimolar to the amount of ferric iron the rate corresponds approximately to that observed with the corresponding amount of ferric versenate; that is, the rate is determined by the amount of ferric versenate rather than by the total amount of ferric iron. Latex of normal fluidity is obtained with charges containing 0.5 part or more of potassium chloride; without added electrolyte thick latex subject to precoagulation is obtained. Satisfactory rates are found with mixtures of Dresinate 214 and K-fatty acid soap. Mercaptan is not needed for initiation; the same rate is found with n-dodecyl mercaptan, with sulfole mercaptan, and without mercaptan. The kind of agitation has no or slight effect on the rate. Added oxygen has only a slight effect which is largely eliminated by the addition of sodium dithionite. A recipe is given which at -5°C. yields 70-75% conversion in 12 hours. Polymerization using the Veroxasulfide recipe at 25°C. may provide a sensitive test for traces of iron in ingredients used in polymerization recipes, since with 2 × 10-6 M ferric versenate (corresponding to 0.1 p.p.m. of ferric iron per liter of aqueous phase), 32% conversion is reached in 11 hours, whereas in the absence of iron 3% conversion is reached in the same time.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1952.120090505
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    Redox recipes. VI. Redox systems containing potassium chromate as oxidizing constituentThis investigation was carried out under the sponsorship of the Reconstruction Finance Corporation, Synthetic Rubber Division, in connection with the U. S. Government Synthetic Rubber Program. (1952)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 9 (1952), S. 327-342 
    Details
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The emulsion copolymerization of butadiene (75)-styrene (25) is initiated by redox systems containing potassium chromate as oxidizing constituent. In alkaline (soap) recipes, the system chromate-arsenic trioxide is especially effective, giving a rate of conversion of about 20% per hour at 30°C. with 5 parts of potassium myristate (0.3 part of potassium chromate and 0.07 part of arsenic trioxide per 100 parts of monomers). Other fatty acid soaps or sodium alkyl sulfate may be used instead of myristate, although no other soap or emulsifier tested gives a rate as large as does myristate. Mercaptan has a slight accelerating effect but the presence of mercaptan is not necessary for initiation of polymerization. The use of arsenic trisulfide as reducing agent gives rise to rapid polymerization but the rates vary with different suspensions of arsenic trisulfide. Potassium antimonyl tartrate also may be used in combination with chromate to give rapid polymerization at 40°C. with fatty acid soap. Tin(II) is much less effective than either arsenic(III) or antimony(III). Inorganic reducing agents which in combination with chromate are inefficient in initiating the copolymerization include iron(II), thallium(I), dithionite, hydrazine, hydroxylamine, and sulfide.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1952.120090405
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    Paper (German National Licenses)
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