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  • 1
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 176 (1975), S. 2861-2870 
    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 Polymerisation von Acrylamid, gestartet mit dem Redoxpaar Kaliumpermanganat/Thioglykolsäure (1), wurde in saurer wäßriger Lösung bei 30±0,1°C unter trockenem sauerstofffreiem Stickstoff untersucht. Die Anfangsgeschwindigkeit der Polymerisation war im Bereich von 2,0.10-3 bis 6,0.10-3mol/l der ersten Potenz der Kaliumpermanganat-Konzentration nahezu proportional. Außerdem war die Polymerisationsgeschwindigkeit zur ersten Potenz der Acrylamidkonzentration im Bereich von 8,0.10-2 bis 10,0.10-2 mol l-1 proportional. Die Reaktionsgeschwindigkeit scheint außerdem von der Thioglykolsäure-Konzentration im Bereich von 1,0.10-2 bis 1,2.10-2 mol/l unabhängig zu sein. Bei höheren Konzentrationen von 1 vermindern sich jedoch die Geschwindigkeit und der maximale Umsatz. Überschiissige Schwefelsäure beeinflußt die Polymerisationsgeschwindigkeit nur wenig und Säuremangel bringt die Reaktion bei den Versuchsbedingungen früh zum Erliegen, woraus für eine glatte Polymerisationsauslösung eine optimale Schwefelsäuremenge hervorgeht.Kalium- und Ammoniumchlorid vermindern die Anfangs-Polymerisationsgeschwindigkeit, während umgekehrt Mangansulfathydrat und Natriumoxaiat sie beschleunigen. Methanol, Äthanol, 2-Propanol und Butanol drücken den Polymerisationsumsatz herab.
    Notes: The polymerization of acrylamide in aqueous media, initiated by the acidified potassium permanganate/thioglycolic acid (1) redox pair was studied at 30±0,1°C in an inert atmosphere of dry and oxygen-free nitrogen. The initial rate of polymerization was found to be proportional to nearly the first power of potassium permanganate concentration within the range of 2,0.10-3 to 6,0.10-3 moll-1. The rate was also found to be proportional to the first power of [acrylamide] in the range of 8,0.10-2 to 10,0.10-2 moll-1. The rate of polymerization appears to be independent of thioglycolic acid (1) concentration in the range of 1,0.10-2 to 1,2.10-2moll-1. At still higher concentrations, however, the amount of 1 depresses the rate and maximum conversion. An excess of sulphuric acid was found to affect the rate of polymerization to a slight extent and a deficiency of the acid makes the reaction to stop at an early stage, during the range studied. This indicates, therefore, the presence of an optimum concentration of H2SO4 for the smooth initiation of polymerization.A study on the effect of salts reveals that KCl and NH4Cl lower the initial rate of polymerization, whereas the reverse is true for MnSO4.H2O and Na2C2O4. The water-miscible aliphatic alcohols e.g. CH3OH, C2H5OH, (CH3)2CHOH, and C4H9OH were found to depress the extent of polymerization.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 177 (1976), S. 2919-2926 
    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 mit dem Redoxpaar Kaliumpersulfat/2-Mercaptoäthanol ausgelöste Polymerisation von Acrylamid wurde in wäßriger Lösung unter Stickstoff bei 30°C untersucht. Die anfängliche Polymerisationsgeschwindigkeit war proportional zur ca. 1,5ten Potenz der Kaliumpersulfatkonzentration im Bereich von 0,6 bis 2,0 mmol l-1 und der ersten Potenz der Acrylamidkonzentration im Bereich von 0,1 bis 0,14 mol l-1. Die Geschwindigkeit war auch proportional der ersten Potenz der 2-Mercaptoäthanolkonzentration im Bereich von 4,0 bis 8,0 mmol l-1. Die Gesamtaktivierungsenergie war 134 kJ mol-1.Weiterhin wurde der Einfluß von Salzen (NaCl, KCl, NH4Cl, Na2C2O4, K2C2O4·H2O, (NH4)2C2O4, MnSO4·4H2O und NaF) und von verschiedenen aliphatischen Alkoholen (Methanol, Äthanol und Propanol) untersucht.
    Notes: The polymerization of acrylamide in aqueous media initiated by the potassium persulfate/2-mercaptoethanol redox pair was studied at 30°C under nitrogen atmosphere. The initial rate of polymerization was found to be proportional to nearly the 1,5th power of the potassium persulfate concentration within the range of 0,6 to 2,0 mmol l-1 and to the first power of acrylamide concentration in the range of 0,1 to 0,14 mol l-1. The rate was also found to be proportional to the first power of the 2-mercaptoethanol concentration within the range 4,0 to 8,0 mmol l-1. The overall activation energy was found to be 134 kJ mol-1.Further the effect of salts (NaCl, KCl, NH4Cl, Na2C2O4, K2C2O4·H2O, (NH4)2C2O4,MnSO4·4H2O, and NaF) and aliphatic alcohols (methanol, ethanol, and propanol) was tested.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 179 (1978), S. 295-300 
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Aqueous polymerization of acrylamide, initiated by the potassium persulfate-thioglycolic acid redox pair, was studied at 30°C under introgen. The initial rate of polymerization R was found to be approximately proportional to the 0,5th power of potassium persulfate concentration within the range of 0,6 to 1,0 mmol-1. R was also found to vary linearly with the monomer concentration between 0,8 · 10-1 and 1,0·10-1 mol l-1 and to increase with the thioglycolic acid concentration in the interval of 3,0 to 4,0 mmol l-1. The activation energy was estimated to be 126 kJ mol-1. Addition ot NaCl, NaF, and (CH3)4NI lowered the initial rate R while MnSO4 increased it. Some aliphatic alcohols were observed to be polymerization retarders.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
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