The synthesis of urea-formaldehyde resin microspheres has been conducted with different surfactants under the acidic conditions. Narrow size distributions of resin microspheres are obtained in the presence of neutral surfactant Tween80 and cationic CTAB, while in that of anionic surfactant the resin product displays severe aggregation. After the prepolymer particles develop under conditions of neutral or cationic surfactant, the dispersity and spherical integrity of the microspheres improve significantly. Crystallinity of the microsphere products increases and the initial reaction rate slows in the presence of surfactant. In the case of neutral or cationic surfactant, the induction period of the prepolymer particles extends, the Raman absorption enhances, and the charge of the particles is positive, however, in the case of anion surfactant, the results are opposite to that described above. These results could be explained by the influence of surfactant amphiphilic and electrical properties on the nucleation and growth process of urea-formaldehyde resin microspheres.

Key words: urea-formaldehyde resin microsphere, Tween, SDBS, CTAB