Emulsion and miniemulsion polymerization by Nitroxide mediated radical polymerization at low temperatures

Abstract

Among the techniques of controlled radical polymerization, nitroxide mediated polymerization (MRP), using TEMPO (2,2,6,6-Tetramethyl-1-piperidinyloxy) as controller has become effective, versatile, safe, inexpensive and simple technique, and will be used in this work. In the literature, the vast majority of articles presents the application of this technique in homogeneous media (bulk polymerization), and a few papers deal with heterogeneous polymerization (emulsion and miniemulsion). One of the major disadvantages of NMP polymerization in heterogeneous systems is the need of using high temperatures, around 115 to 125 ° C, which are temperatures above the boiling point of water, which may destabilize the system.In our research group, it was possible to successfully perform the controlled polymerization in emulsion using TEMPO at temperatures lower than 100 ° C (90 and 95 º C). In this project, further experiments are performed in emulsion, in order to understand factors affecting the process, for example, the relationship between the acceleration of the reaction and the concentration of sodium bicarbonate (NaHCO3), the relationship between the time induction and operating temperature, etc.. (see more details of the process in the paper Montezuma et al. (2012). and Patent 018110045780. Moreover, the methodology used for the emulsion process will be tested for the miniemulsion process, with the goal of trying to achieve a synthesis in miniemulsion at temperatures below 100 º C, which is a big advantage for the industrial point of view, and is unprecedented in the literature, to our knowledge, for the controller TEMPO. (AU)