Synthesis of zwitterionic polymer by SET-LRP at room temperature in aqueous

摘要

The Cu~0-mediated single electron transfer-living radical polymerization of acrylamide and N,N-dimethyl-N-methacryloyloxyethyl-N- sulfobutyl ammonium in aqueous at 25 °C using 2-chloropropionamide as initiator with Cu~0 powder/tris-(2-dimethylamino ethyl)amine (Me 6-TREN) as catalyst system is studied. The results showed the characteristic of the "living" polymerization that were the M _n of polymers increased linearly with monomer conversion and the ln([M]_0/[M]) increased linearly with time too, meanwhile the narrow molecular of weight distributions were found at most cases. Because of the high rate constant of propagation and bimolecular termination of the acrylamide, the external addition of CuCl_2 is required to mediate deactivation the early stage of polymerization. In addition, the disproportionation constant of CuIX/L in H_2O is higher than in other solvents and the coordination of amino group and Cu~(II) takes place easily, so the isopropanol or N,N-dimethylformamide is added to control the polymerization. High conversions were achieved within short time and the polymers prepared showed good antipolyelectrolyte properties in inorganic salts solutions.