Atom transfer radical polymerizations of methyl methacrylate and styrene with an iniferter reagent as the initiator

摘要

Three novel iniferter reagents were synthesized and used as initiators for the polymerizations of methyl methacrylate (MMA) and styrene (St) in the presence of copper(I) bromide and N,N,N',N '',N ''-pentamethyl-diethylenetriamine at 90 and 115 degrees C, respectively. All the polymerizations were well controlled, with a linear increase in the number-average molecular weights during increased monomer conversions and relatively narrow molecular weight distributions (weight-average molecular weight/ number-average molecular weight <= 1.36) throughout the polymerization processes. The polymerization rate of MMA was faster in bulk than that in solution and was influenced by the different polarities of the solvents. A slight change in the chemical structures of the initiators had no obvious effect on the polymerization rates of MMA and St. The initiator efficiency toward MMA was lower than that toward St. The results of H-1-NMR, matrix-assisted laser desorption/ionization time-of-flight mass spectrum analysis, and chain-extension experiments demonstrated that well-defined poly(methyl methacrylate) and polystyrene bearing photolabile groups could be obtained via atom transfer radical polymerization (ATRP) with three iniferter reagents as initiators. The polymerization mechanism for this novel initiation system was a common ATRP process. (c) 2007 Wiley Periodicals, Inc.