A systematic study of the phase behavior, microstructure, and polymerization kinetics of n-hexyl methacrylate in mixed dodecyltrimethylammonium bromide/didodecyldimethyl ammonium bromide cationic microemulsions has led to the development of a simple but accurate parameter-free kinetic model. This model has been extended to predict the evolution of the absolute molecular weight and particle-size distribution. Results of online small-angle neutron scattering (SANS) studies on the polymerizing microemulsion support the assumptions of a polymer core/monomer shell particle morphology and equilibrium monomer partitioning between the monomer swollen micelle cores and the monomer shell of the particles. The SANS spectrum of the fully polymerized microemulsion is quantitatively represented by the particle-size distribution model using literature values for the polymerization parameters and three adjustable parameters, two of which can be accurately obtained from separate small-angle neutron scattering experiments on the monomer-free mixed surfactant system.

 

Recent and Current Researchers:
Kevin Hermanson
Jennifer O'Donnell
Selected Publications:
  • "Transition from Microemulsion to Emulsion Polymerization: Mechanism and Final Properties", E.W. Kaler and K. D. Hermanson, Journal of Polymer Science Part A, 20, 5253 (2004).
  • "Kinetics and Mechanism of the Multiple Addition Microemulsion Polymerization of Hexyl Methacrylate", K. D. Hermanson and E. W. Kaler, Macromolecules, 36, 1836 (2003).
  • "Microemulsion Polymerization. 3. Molecular Weight and Particle Size Distributions", C. C. Co, P. Cotts, S. Burauer, R. de Vries and E. W. Kaler, Macromolecules, 34, 3245 (2001).
  • "Microemulsion Polymerization. 1. Small-Angle Neutron Scattering Study of Monomer Partitioning", C. C. Co, R. de Vries and E. W. Kaler, Macromolecules, 34, 3224 (2001).
  • "Microemulsion Polymerization. 2. Influence of Monomer Partitioning, Termination, and Diffusion Limitations on Polymerization Kinetics", R. de Vries, C. C. Co and E. W. Kaler, Macromolecules, 34, 3233 (2001).
  • "Free Radical Polymerizations in Microemulsions", in "Reactions and Synthesis in Surfactant Systems", C. Co, R. de Vries and E. W. Kaler, edited by J. Texter (2001).
  • "Particle Size and Monomer Partitioning in Microemulsion Polymerization 2. Online Small Angle Neutron Scattering Studies," Macromolecules, 31, 3203 (1998).
  • "Particle Size and Monomer Partitioning in Microemulsion Polymerization 1. Calculation of the Particle Size Distribution," Macromolecules, 31, 3197(1998).
  • "Kinetics and Mechanism of Microemulsion Polymerization of Hexyl Methacrylate," Macromolecules, 30, 1897 (1997).
Patents:
  • "Microemulsion Polymerization Systems and Coated Materials Made Therefrom", US Patent 5,376,441 and US Patent 5,385,694.
  • "Process for Coating Microporous Substrates and Products Therefrom", US Patent 5,460,872.
  • "Microemulsion Polymerization Systems and Coated Materials Made Therefrom", US Patent 5,539,047.