Schiff base as a novel kind of catalyst for reversible complexation-mediated radical polymerization of methyl methacrylate

Two kinds of Schiff base, N,N '-dibenzylidene-1,2-diaminoethane (NDBE) and N,N '-disalicylidene-1,2-diaminoethane, have been found as efficient organic catalyst for reversible complexation-mediated radical polymerization (RCMP) of methyl methacrylate (MMA) for the first time. The polymerization results show obvious features of "living"/controlled radical polymerization. Well-defined and low-polydispersity polymers (M-w/M-n = 1.20-1.40) are obtained in RCMP of MMA catalyzed by Schiff base at mild temperature (65-80 degrees C). Moreover, Schiff base also exhibits a particularly high reactivity for RCMP of MMA with in situ formed alkyl iodide initiator. The polymer molecular weight and its polydispersity (M-w/M-n is around 1.20) are well controlled even with high monomer conversion. Notably, when the dosage of azo initiator is same as the dosage of iodine, the polymerization could also be realized in the presence of NDBE. The living feature of synthesized polymer is confirmed through the chain extension experiment. In short, Schiff base is a kind of high-efficient catalyst for RCMP and reverse RCMP of MMA, which can be one of the most powerful and robust techniques for polymer synthesis. (c) 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1653-1663