New Ligands for the Living High-Molecular-Weight Anionic (Co)Polymerization of Acrylates in Toluene at 0 °C. 3. Ligation of sec-Butyllithium by Lithium Silanolates

Abstract

sec-Butyllithium combined with a new family of ligands, (i.e., lithium silanolates), has been used to initiate the ligated anionic polymerization of n-butyl acrylate (BuA) in toluene at low temperature. Compared to other μ-ligands, sBuMe2SiOLi is a more efficient stabilizer of the active centers. Thus, under selectively chosen reaction conditions, the polymerization proceeds quantitatively at −40 °C, producing a high-molecular-weight polymer with narrow-molecular-weight distribution ( / < 1.2). When the copolymerization of BuA is initiated by a living {PMMALi, 5·sBuDLi} in toluene at −78 °C, the experimental data agree with a well-controlled block copolymerization reaction, since the final molecular-weight distribution is very narrow ( / ≤ 1.1) and the polymerization efficiency very high.