Dependencies of the first and second moments of copolymer composition on conversion - a new discrimination tool of radical copolymerization mechanisms
✍ Scribed by Georgiev, Georgi S; Koseva, Nely S; Christov, Latchezar K
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 114 KB
- Volume
- 48
- Category
- Article
- ISSN
- 0959-8103
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✦ Synopsis
A method discriminating between terminal and complex copolymerization mechanisms based on the comparison of the experimentally-determined dependences of the average and the instantaneous copolymer composition and its dispersion on conversion with those derived from the model schemes is suggested. The analysis of the conversion dependences allows the assessment of the copolymer compositional homogeneity and the dominating mechanism of chain propagation. An easily applicable criterion proving monomer complex participation for the cases when the composition curve crosses the azeotropic line has been de®ned on the dependence of the monomer feed composition at which dispersion has minimum value on conversion. It is also shown that conversion curves carry information about changes in the kinetic, hydrodynamic and thermodynamic characteristics of the reaction medium. The ef®ciency of the suggested methods has been tested for the copolymerization of acrylic acid and 1-vinyl-2-pyrrolidone.