SYNTHESIS AND CHARACTERIZATION OF EPOXY-FUNCTIONAL POLYSTYRENE PARTICLES

Colloidal polystyrene particles with surface epoxy groups have been sy nthesized through surfactant-free emulsion copolymerization of styrene with glycidyl methacrylate; and through copolymerization of glycidyl methacrylate (GMA) and methyl methacrylate as shells around existing p olystyrene seed particles. We developed two titration methods to quant ify the number of epoxy groups that survived the polymerization proces ses. The styrene-GMA copolymer particles were judged to be unsatisfact ory as model colloidal materials due to their size polydispersity and unknown internal distribution of epoxy groups. The core-shell particle s had high epoxy surface densities with at least 60% of the initial ep oxy groups surviving the synthesis process. Transmission electron micr oscopy shows that the thickness of the epoxy-rich shell is less than e xpected based on the volume of monomers added, suggesting that some of the monomer forms water-soluble oligomers. Photon correlation spectro scopy measurements imply that the shell is swollen with water and cons ists of polymer configurations which extend out into solution. The mor phological details vary consistently with the GMA content, and hence t he hydrophilicity, of the shell polymer. (C) 1995 John Wiley and Sons, Inc.