ANIONIC RING-OPENING POLYMERIZATION OF CYCLODISILAZANES .2. INFLUENCEOF ADDITIVES ON THE KINETICS OF POLYMERIZATION

The kinetics of the anionic ring-opening polymerization of the (DNMeDN Me)-D-Vi cyclodisilazane, initiated by benzyllithium, has been investi gated in different experimental conditions. In non-polar solvents, the active centers are aggregated ion pairs which are in equilibrium with a small amount of monomeric species. In the presence of additives suc h as THF, dioxane or tetramethyl-ethylenediamine, there is only one ty pe of active center. The aggregates are dissociated into tight ion pai rs externally solvated by the additive. The paper demonstrates also th at the kinetics of the polymerization (i. e., rate constant of propaga tion k(p)) is a function of both the nature and the amount of additive s.