Anionic Polymerization of (Meth)acrylic Monomers. 7. Macrocyclic Crown Ethers as Promoters of the Living Polymerization of Methyl Methacrylate Using Monofunctional Initiators

peer reviewedIt has been previously shown that μ-coordinating inorganic salts, such as LiCl, were effective in preventing the anionic polymerization of methacrylic esters and hindered alkyl acrylates from being disturbed by secondary transfer and termination reactions. That strategy has opened the way to the “living” polymerization of these monomers and their controlled sequential polymerization with monomers lacking a carbonyl-conjugated group. That control is however limited to THF at low temperatures for methyl methacrylate and tert-butyl acrylate. It is reported now that the polymerization mechanism remains strictly controlled in apolar solvents, such as toluene, and at temperatures as high as 0 °C, when crown ethers are used in relation to their capability of chelating the alkali-metal counterion and surrounding it with a steric barrier blocking a large enough space area around the metal-containing ion pair. © 1992, American Chemical Society. All rights reserved