| 초록 |
We used photo-initiated RAFT process to synthesis poly(N-vinylpyrrolidone) (PVP) with controlled MW and MWD. To achieve successful photo-initiated RAFT process, it is required to use photo-chemically stable chain transfer agent (CTA), along with additional photoinitiator, BAPO. On testing various xanthate CTA for thermal RAFT of NVP, methyl (ethoxycarbonothioyl)sulfanyl propionate (MESP) was identified as an effective RAFT agent for the polymerization of PVP. However, when photo-initiation process was applied, the polymerization system loses its control to give high polydispersity index. The reason of the poor control was turned out to be the decomposition of MESP under the conditions of UV irradiation. A set-up of varying UV energy was developed by using LEDs with different wavelength to prevent the decomposition of MESP. Detailed results of photo-initiated RAFT process of NVP under the conditions will be discussed. |
