Mortamet, A. C. and Pethrick, R. A. (2012) Redox initiated free radical polymerization of 4-methylstyrene. Journal of Applied Polymer Science, 123 (3). pp. 1539-1547. ISSN 0021-8995Full text not available in this repository. (Request a copy from the Strathclyde author)
Studies of the thermally initiated polymerization of 4-methylstyrene using alkylperoxide in conjunction with cobalt and tertiary amine catalysts are reported. Addition of cobalt salts leads to a facile low temperature initiation of the polymerization process. The polymerization process was investigated using differential scanning calorimetry [DSC] and vibrating probe rheological measurements. Color changes which occur when the cobalt complex and peroxide are combined were studied using UV-visible spectroscopy. The kinetics of polymerization was investigated using two different cobalt complexes. The initiation step in the polymerization is the conversion of the cobalt (II) to cobalt (III). The presence of the tertiary amine does not affect the oxidation state of the cobalt complex. The cobalt (III) complex gives a better rate of conversion than the cobalt (II) complex. The polymerization process is discussed in terms of redox reaction between the cobalt complex and the alkyperoxide. At low temperatures, the rate of conversion obeys simple Arrhenius kinetics. At higher temperatures the effects of gelation and catalysts inhibition influence the polymerization process. The polymerization process is sensitive to the level of available oxygen during the initiation step and inhibition by aldehyde is observed.
|Keywords:||cobalt catalysis, cobaltic ion, aqueous solution, gelation, 4-methylstyrene, vinyl polymerization, benzaldehyde inhibition, free radical polymerization, Haber-Weiss catalytic cycle, Physical and theoretical chemistry, Materials Chemistry, Polymers and Plastics, Surfaces, Coatings and Films, Chemistry(all)|
|Subjects:||Science > Chemistry > Physical and theoretical chemistry|
|Department:||Faculty of Science > Pure and Applied Chemistry|
|Depositing user:||Pure Administrator|
|Date Deposited:||22 Jun 2012 14:21|
|Last modified:||27 Apr 2016 18:40|