A. Molenberg, M. Möller
Mar 1, 1997
Citations
1
Influential Citations
12
Citations
Journal
Macromolecular Chemistry and Physics
Abstract
The use of the phosphazene base P 2 -Et a) as a promoter for the anionic polymerization of hexamethylcyclotrisiloxane (D 3 Me ) or hexaethylcyclotrisiloxane (D 3 Et ) initiated by an organolithium compound leads to well-defined polysiloxanes. At low conversion (< ca. 9%) the polymerization of D 3 Me behaves like a living polymerization, however, polymers with a narrow molecular weight distribution (M W /M n < 1.1) are obtained up to much higher conversions (ca. 70%). Kinetic data and NMR spectroscopy revealed the existence of a dynamic equilibrium between complexed and uncomplexed lithium silanolates. Below ambient temperature several different types of aggregates were indicated. The occurrence of an acceleration was observed after ca. 9% conversion.