The reverse atom transfer radical polymerization of methyl methacrylate in the presence of some polar solvents

The reverse atom transfer radical polymerization (RATRP) of methyl methacrylate (MMA), with AIBN (AIBN/CuCl2/bpy=1:2:4) as initiator and acetonitrile as solvent at 60°C can be achieved successfully. It was found that the polydispersity index (PI) of poly(methyl methacrylate) (PMMA) synthesized by using RATRP with bipyridine as ligand was as narrow as 1.08, but the polymerization induction time was quite long. The effects of reaction temperatures, different ligands and solvents on this RATRP system were studied in detail. The RATRP of MMA with 1,10-phenanthroline as ligand and acetonitrile as solvent is a `livingʹ/controlled polymerization. When the N,N-dimethylformamide was used to replace the acetonitrile, the RATRP rate of MMA is faster and the PI of PMMA is narrower. The prepared PMMA containing chlorine end groups with narrow polydispersity can initiate the polymerization of styrene (St) quantitatively to produce well-defined P(MMA-b-St) with CuX/bpy as catalyst at 120°C. This block copolymer was characterized by 1H-NMR. It is evident that the possibility of conventional free radical polymerization of MMA in RATRP due to the decomposition of AIBN could be neglected.