Homogeneous atom transfer radical polymerization of methyl methacrylate under pulsed microwave irradiation

The homogeneous atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) was successfully carried out under pulsed microwave irradiation (PMI), using N,N-dimethylformamide (DMF) as a solvent, with ethyl 2-bromobutyrate (EBB)/CuCl/N,N,N',N',N"-pentamethyidiethylenetriamine (PMDETA) as an initiating system. Plots of ln([M](0)/[M]) vs. time and molecular weight with narrow dispersities, 1.1 < M-w/M-n < 1.5, vs. conversion showed a linear dependence. The dependences of the rate of polymerization on mole ratios of [MMA](0)/[EBB](0)/[CuCl](0)/[PMDETA](0) and the concentrations of ligand were presented. In comparison with the identical ATRP of MMA under the conventional heating (CH), the apparent rate constant of polymerization (k(P)(app)) under PMI was 5.3-12.8 times larger than that under CH, indicating a significant increase of the polymerization rate of homogeneous ATRP of MMA under PMI.