Jin-Shan Wang

A new family of "ligated" anionic initiators for the "living" polymerization of (meth)acrylic esters

SummaryA new family of ligands (dual σ-π ligand), i.e. chelating lithium alkoxides, Li-O-(CH2-CH2O)nCH3, is shown to be very effective in promoting the living anionic polymerization of methacrylic and acrylic esters, including a number of primary alkyl acrylates such as n-butyl acrylate and 2-ethylhexylacrylate.

Anionic polymerization of various methacrylates initiated with LiCl-complexed sBuLi

Abstract A simple alkyl lithium initiator (sBuLi) complexed with LiCl (10 molar equiv.) has been used to initiate the anionic polymerization of various methacrylic monomers, i.e. methyl methacrylate (MMA), tert-butyl methacrylate (tBuMA), glycidyl methacrylate (GMA), and dimethyl amino ethyl methacrylate (DMAEMA) in tetrahydrofuran at −78°C. Only the homopolymerization of tBuMA proceeds in a living manner, as evidenced by both the linear plot of experimental molecular weight (Mnexp) vs theoretical ones (Mncal) (slope ≅ 0.93) and monomer resumption experiments. However, three types of block copolymers, i.e. PtBuMA-b-PMMA, PtBuMA-b-PGMA, PtBuMA-b-PDMAEMA, have been successfully synthesized with a predictable molecular weight, and narrow molecular weight distribution.