Catalytic effect of dimethyl sulfoxide in the Cu(0)/tris(2-dimethylaminoethyl)amine-catalyzed living radical polymerization of methyl methacrylate at 0-90 °C initiated with CH3CHClI as a model compound for α,ω-di(iodo)poly(vinyl chloride) chain ends

A variety of conditions, including catalysts [CuCl, CuI, Cu2O, and Cu(0)], ligands [2,2'-bipyridine (bpy), tris(2-dimethylaminoethyl)amine (Me-6-TREN), polyethyleneimine, and hexamethyl triethylenetetramine], initiators [CH3CHClI, CH2,I-2 CHI3, and F(CF2)(8)I], solvents [diphenyl ether, toluene, tetrahydrofuran, dimethyl sulfoxide (DMSO), dimethylformamide, ethylene carbonate, dimethylacetamide, and cyclohexanone], and temperatures [90, 25, and 0 degrees C] were studied to assess previous methods for poly(methyl methacrylate)-b-poly(vinyl chloride)-b-poly(methyl methacrylate) (PMMA-b-PVC-b-PMMA) synthesis by the living radical block copolymerization of methyl methacrylate (MMA) initiated with alpha,omega-di(iodo)poly(vinyl chloride). CH3CHClI was used as a model for a,co-di(iodo)poly(vinyl chloride) employed as a macroinitiator in the living radical block copolymerization of MMA. Two groups of methods evolved. The first involved CuCl/bpy or Me-6-TREN at 90 degrees C, whereas the second involved Cu(O)/Me-6-TREN in DMSO at 25 or 0 degrees C. Related ligands were used in both methods. The highest initiator efficiency and rate of polymerization were obtained with Cu(O)/Me-6-TREN in DMSO at 25 degrees C. This demonstrated that the ultrafast block copolymerization reported previously is the most efficient with respect to the rate of polymerization and precision of the PMMA-b-PVC-b-PMMA architecture. Moreover, Cu(O)/Me-6-TREN-catalyzed polymerization exhibits an external first order of reaction in DMSO, and so this solvent has a catalytic effect in this living radical polymerization (LRP). This polymerization can be performed between 90 and 0 degrees C and provides access to controlled poly(methyl methacrylate) tacticity by LRP and block copolymerization. (c) 2005 Wiley Periodicals, Inc.