Synthesis of Hyperbranched and Highly Branched Methacrylates by Self-Condensing Group Transfer Copolymerization

摘要: We report a study of the self-condensing group transfer copolymerization initiator−monomer (“inimer”) 2-(2-methyl-1-triethylsiloxy-1-propenyloxy)ethyl methacrylate (MTSHEMA) with methyl (MMA). The highly branched polymethacrylates were characterized by multidetector SEC and NMR. Kinetic measurements show that cyclization, i.e., intramolecular reaction an active center vinyl polymer, limits molecular weights lowers polydispersity. Depending on comonomer ratio, γ = [MMA]0/[MTSHEMA]0, up to Mw 240 000 at polydispersity Mw/Mn ≈ 3 could be obtained. Mark−Houwink exponent these copolymers depends ratio is significantly lower (0.45 ≥ α 0.23) than linear PMMA (α 0.69). Only 4% inimer are necessary half value PMMA. Using slow addition mixture monofunctional initiator 1-methoxy-3-(trimethylsilyloxy)-2-methyl-...