Get access

A new method to determine monomer concentration in the polymer particles of emulsion polymerization systems by dynamic light scattering

Authors

  • Mahdi Abdollahi,

    Corresponding author
    1. Division of Polymer Science and Technology, Research Institute of Petroleum Industry (RIPI), Tehran 14665-1998, Iran
    • Division of Polymer Science and Technology, Research Institute of Petroleum Industry (RIPI), Tehran 14665-1998, Iran
    Search for more papers by this author
  • Mahmoud Hemmati

    1. Division of Polymer Science and Technology, Research Institute of Petroleum Industry (RIPI), Tehran 14665-1998, Iran
    Search for more papers by this author

Abstract

Emulsifier-free emulsion polymerization of styrene was performed in the presence of small amount of methacrylic and itaconic acids as carboxylic acid monomers and potassium persulfate as an initiator at 70°C to prepare monodisperse polymer particles. Diameter of monomer swollen polymer particles (dpswol) was measured by dynamic light scattering for samples taken from the reaction mixture during the Intervals II and III of the emulsion polymerization. Graphically treatment of dpswol versus conversion data allowed us for the first time to directly determine the critical monomer conversion (xc), from which constant monomer concentration in the polymer particles (CMP) during the Interval II was then calculated. xc and CMP were obtained to be 0.379 and 5.68, respectively. CMP value is in good agreement with that obtained by centrifugation method and those reported in the literature for the similar system. Attempts were also made to evaluate the average number of growing chain per particle ( equation image) during the Interval II of emulsion polymerization of styrene. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Get access to the full text of this article

Ancillary