Photo-induced single-electron transfer living radical polymerization (SET-LRP) of MMA in the presence of ZnO

In this study, the photo-induced single-electron transfer living radical polymerization (SET-LRP) of methyl methacrylate (MMA) was successfully performed in N,N-dimethylformamide (DMF) with ethyl alpha-bromoisobutyrate(EBiB)/Fe(0)/tetramethylethylenedia mine(TMEDA)/[ZnO] as the initiating system. ZnO was used as the inorganic photoinitiator. The living nature of the photo-induced SET-LRP of MMA was confirmed by kinetic studies in the presence or absence of air. The plot of ln([M](0)/[M]) versus polymerization reaction time was linear, and the molecular weight distribution (MWD) of the resulting PMMA was narrow. The effects of the amounts of Fe(0)/TMEDA, EBiB, ZnO, and light intensity on the photo-induced SET-LRP of MMA were investigated. The conversion increased with increasing the amounts of Fe(0)/TMEDA, EBiB, and ZnO. Increasing the light intensity resulted in a higher polymerization reaction rate. The catalyst and ZnO played important roles in the photo-induced SET-LRP of MMA. The polymerization proceeded in an uncontrollable fashion when the molar ratio of Fe(0)/TMEDA was 0: 0.1, and no reaction took placed in the absence of ZnO. In comparison with other SET-LRP of MMA in bulk or conventional solvents, the photo-induced SET-LRP of MMA proceeded periodically when the light was turned on or off under the mild experimental conditions. The polymerization did not take place when the light was turned off. However, the polymerization was very fast when the light was turned on. The chemical structure of resulting PMMA was characterized by (HNMR)-H-1. The living characteristics were demonstrated by chain extension experiment.