Semicontinuous heterophase polymerization under monomer starved conditions to prepare nanoparticles with narrow size distribution |
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| Authors: | Raquel Ledezma M Esther Treviño Luis E Elizalde Lourdes A Pérez‐Carrillo Eduardo Mendizábal Jorge E Puig Raúl G López |
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| Institution: | 1. Centro de Investigación en Química Aplicada, Boul. Ing. Enrique Reyna No. 140, Saltillo, Coah. 25253, México;2. Departamentos de Química e Ingeniería Química, Universidad de Guadalajara, Boul. M. García Barragán No. 1451, Guadalajara, Jal. 44430, México;3. Centro de Investigación en Química Aplicada, Boul. Ing. Enrique Reyna No. 140, Saltillo, Coah. 25253, MéxicoCentro de Investigación en Química Aplicada, Boul. Ing. Enrique Reyna No. 140, Saltillo, Coah. 25253, México |
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| Abstract: | The semicontinuous polymerization of methyl methacrylate (MMA) in heterogeneous medium under monomer‐starved conditions is reported here. The effect of monomer addition rate on kinetics, particle size, particle number, and PMMA average molar masses are reported. This process permits the synthesis of high‐solid content latexes containing nano‐sized particles (<40 nm) with narrow particle size distributions (Dw/Dn) < 1.1]. Moreover, the molar masses (Mn ≈ 0.3–1.2 × 106 g/mol) are much lower than those expected by chain transfer to monomer, which is the typical termination mechanism in 0–1 emulsion and microemulsion reactions. Both particle size and average molar masses decrease as the rate of monomer addition is diminished. Possible explanations for this process are provided. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1463–1473, 2007 |
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| Keywords: | kinetics (polymerization) latexes nanoparticles particle size distribution radical polymerization |
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