Dispersion Polymerization of N-Vinylformamide in Polar Media. Preparation of Monodisperse Hydrophilic Polymer Particles

Abstract

Dispersion polymerization of N-vinylformamide (NVF) in polar media has been performed using poly(2-ethyl-2-oxazoline) as stabilizer. The polymerization in methanol gave micron-size monodisperse particles of highly hydrophilic polymers. Particle size increased as the stabilizer concentration decreased. Effects of the monomer concentration and the solvent composition upon the particle size and size distribution have been examined. The polymerization in the presence of a divinyl compound afforded crosslinking polymer particles. In using a hydrophilic poly(2-methyl-2-oxazoline) macromonomer bearing polymerizable styryl group instead of poly(2-ethyl-2-oxazoline), monodisperse polymer particles in the sub-micron range were obtained. The macromonomer acted as a stabilizer as well as a comonomer. The substituent of the macromonomer affected the particle size.