Emulsifier-free, organotellurium-mediated living radical emulsion polymerization (emulsion TERP): Effect of monomer hydrophilicity

• Published in: Journal of polymer science. Part A, Polymer chemistry Polymer chemistry, 2013-02, Vol.51 (3), p.716-723
• Main Authors: Kitayama, Yukiya, Kishida, Kazuya, Okubo, Masayoshi
• Format: Article
• Language: English
• Subjects: Applied sciences; Control equipment; Droplets; Emulsion polymerization; Exact sciences and technology; Monomers; Organic polymers; organotellurium-mediated living radical polymerization (TERP); particle; Physicochemistry of polymers; Polymerization; Polymethyl methacrylates; Preparation, kinetics, thermodynamics, mechanism and catalysts; Radicals; self-assembly; Stirring; styrene
• ISSN: 0887-624X; 1099-0518
• DOI: 10.1002/pola.26430

Emulsifier‐free, organotellurium‐mediated living radical emulsion polymerizations (emulsion TERPs) of methyl methacrylate (MMA) and n‐butyl methacrylate (BMA) with dimethyl ditelluride were carried out at two different stirring rates (220 rpm and 1000 rpm). In the emulsion TERP of MMA as a hydrophilic monomer, the molecular weight distribution (MWD) controls with both stirring rates were good with high polymerization rate (100% conversion at 1.5 h). On the other hand, in the emulsion TERP of BMA as a hydrophobic monomer, at 220 rpm the polymerization rate was much slow (∼50% conversion at 22 h) and the MWD control was bad, but at 1000 rpm the polymerization was completed within 7 h and MWD control was good. These results suggest that monomer transportation from droplets to polymerizing particles via aqueous medium is important for good MWD control and steady polymerization in the emulsion TERP. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013 The effect of monomer hydrophilicity was investigated in emulsifier‐free, organotellurium‐mediated living radical polymerization (emulsion TERP) using methyl methacrylate and butyl methacrylate. When hydrophilic monomer was used, MWD control was good only at an efficient and inefficient stirring rates. However, when hydrophobic monomer was used, good MWD control was obtained only at an efficient stirring rate. These results suggest that monomer transportation from droplets to polymerizing particles via aqueous medium is important for good MWD control.