Synthesis of star polymethyl acrylate by SET-LRP at ambient temperature

The star-shaped polymethyl acrylate (PMA) was synthesized by single electron transfer living radical polymerization (SET-LRP) at 30 °C in dimethyl sulfoxide, using 2,2-dibromomethyl-1,3-dibromopropane as the multifunctional initiator, Cu0 powder and tris-(2-dimethylamino ethyl)amine (Me6-TREN) as catalyst. The structure of polymer was analyzed by 1H NMR, and the results showed that the star-shaped PMA had perfect chain ends (–Br) retention. In addition, the polymerization proceeded smoothly and the time dependence of ln([M]0/[M]) was linear, which could indicate a first order propagation rate with respect to both radicals and monomer concentration, the polymerization was the living polymerization. The M n and M w/M n of polymer were being measured by Gel Permeation Chromatography. The k p app = 0.0367 h−1 and the conversion was 36.3% at 16 h, meanwhile the M n GPC of the polymer was 13,300 and the M w/M n was 1.40.