Synthesis of Urea-Formaldehyde Polymeric Nanoparticles via two Microemulsions Method

Urea–formaldehyde (UF) resins can be used in various fields; such as wood adhesives, paper industry, pigments, varnish, lightweight filling materials and additives in the plasticsindustry [1]. Also, there are a plenty of patents registered about the preparation and applications of UF resin powders,indicating the industrial and commercial importance of these materials [2]. Furthermore, if one can make some improvements in mechanical and physical properties of thesepolymers, the range of their applications will be increased extensively. For example, the shape and size of polymericparticles have a great influence on the specific properties and consequently, on their applicability. Hence, investigation and development of the novel techniques for the preparation of these polymeric nanoparticles, with a well defined and specific shape and size, as well as size distribution is animportant issue for the polymer chemists. In this work, the urea-formaldehyde resin nanoparticles were synthesized byemploying two microemulsions method. Microemulsions as a thermodynamically stable mixtures of at least one oil, a surfactant and aqueous phase, offer a very powerful tool forthe preparation of nanostructured materials [3]. The preparation of the phase diagrams of the micremulsions is aspecially important issue in this field to determine the propercompositions of the two required microemulsions [4]. Waterin- oil (w/o) microemulsions have been introduced as a simpleway for the synthesis of polymeric nanoparticles with low polydispersity under a very mild reaction conditions. Thistechnique allows us to tune the size and even shape of the produced nanoparticles [5].