Thermodynamic enhancement of oligomers in dynamic living polymer system involving end-group interaction. Distribution of living oligomers in equilibrated polydimethylsiloxanes
✍ Scribed by M. Mazurek; M. Šcibiorek; J. Chojnowski; B.G. Zavin; A.A. Zhdanov
- Publisher
- Elsevier Science
- Year
- 1980
- Tongue
- English
- Weight
- 559 KB
- Volume
- 16
- Category
- Article
- ISSN
- 0014-3057
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✦ Synopsis
Al~traet--The concentrations of living oligomers of structure MtO[Si(Me)20],Mt (n = 1 to 8, Mt = Na, K or Cs) are studied at equilibrium in the polymerization of permethylcyclopolysiloxanes initiated with alkali metal silanolates. The amounts of these oligomers are considerably higher than expected from the most probable distribution of molecular sizes, which is generally accepted as the distribution of linear chain size in equilibrated polydimethylsiloxane. This phenomenon is a consequence of interaction between living ends in connection with a dynamic character of a living polydimethylsiloxane system in which fast chain scrambling occurs. Other systems showing these features are expected to exhibit similar effects.