Preparation of Polyvinylpyrrolidone Fine Particles by Inverse Emulsification-Evaporation Process in Solvent

The paper presents a novel preparation method for polyvinylpyrrolidone (PVP) fine particles in nonpolar aliphatic hydrocarbons, using Isopar as a continuous phase. The particles have been prepared by the inverse emulsification of methanol droplets containing PVP into Isopar in the presence of Solsperse 17000 as a dispersant, followed by an evaporation process in the solvent. The factors which affect the particle size and distribution are the viscosity values of continuous and dispersed phases, the concentration of PVP and dispersant. Submicronsized PVP fine particles are found to be obtained under favorable condition, using Isopar-M as a continuous medium: 30wt% of PVP tomethanol, 2.6wt% of solsparse 17000 to Isopar-M. The present technique is found to be a promising method to prepare the functional colored polymeric particles in the hydrocarbon media.