| 초록 |
We applied a RAFT agent bearing carboxyl acid group to miniemulsion polymerization of methyl methacrylate (MMA) in order to prepare stability-enhanced functionalized latex. At the polymerization temperatures of 60, 70, and 80℃, the polymerization kinetics, development of molecular weight and PDI are found to be strongly dependent on the temperature. The higher the temperature, the faster the polymerization rate, lower molecular weight and lower PDI are obtained. The PMMA nano-particles prepared by the miniemulsion polymerization using this type of RAFT agent show some interesting characteristics. According to the FT-IR investigation, it is ensured the RAFT agent is present in the synthesized polymer molecules, which will affect the properties of the final latex. As the RAFT agent increases, the magnitude of zeta potential and conductivity correspondingly increases and the size of the PMMA nano-particle decreases from 118.8 nm to 49.5 nm. These results imply that the carboxyl group (or partially in anionic form) are present on the surface of the polymer particles and therefore, the stability of the system is enhanced. With respect to the stability issue, no noticeable sign of creaming or destabilization was observed for at least several months by remaining homogeneous. |
