Study on the reverse atom transfer radical polymerization of methyl methacrylate

The reverse atom transfer radical polymerization (RATRP) of methyl methacrylate (MMA), with acetonitrile as solvent and AIBN (AIBN/CuCl2. 2H(2)O/1, 10 - phenanthroline or bpy = 1:2:4 molar ratio) as initiator at 60 degreesC has been achieved successfully. It was found that the polydispersity of poly (methyl methacrylate) (PMMA) synthesized by using RATRP with bpy as ligand was as narrow as 1.08, but the inducing period of polymerization was quite long. While bpy was replaced with 1,10 - phenanthroline (phen) as ligand, increases of both polymerization rate for MMA and polydispersity index (at round 1.40) for PMMA were observed. Thus, the mixture ligand of bpy and phen could be used to adjust the polymerization rate of MMA and the polydispersity of PMMA for such a RATRP system. The prepared PMMA containing end group of chlorine with narrow polydispersity could initiate the styrene (St) quantitatively to synthesize the well - defined block copolymer of MMA and St with CuX/bpy as catalyst at 120 degreesC. Such a block copolymer was characterized by using GPC and H-1 NMR respectively. It was found that the possibility of general free radical polymerization of MMA in RATRP due to the decomposition of AIBN could be neglected.