Synthesis and characterization of macroinitiator polystyrene and block copolymerization in the presence of sodium nitrite and iron(II) sulfate

In the presence of sodium nitrite and iron( I) sulfate the controlled polystyrenes with different molecular weight weres synthesized. The polystyrene macroinitiator could initiate the polymerization of methyl methacrylate (MMA), methyl acrylate (MA) ethyl acrylate (EA), and styrene (St). All the polymerizations have the characters of the living polymerization that the molecular. weight of the copolymer gradually increased with conversion and the polydispersity indexes are below 1.5. In addition, block copolymer's experimental molecular weight is similar to theoretical molecular weight. The basic mechanism for the control of radical polymerization is thus a nitroxide-mediated process, such as TEMPO, and the price was reduced greatly, which is of benefits to the industries application. The block copolymerization formation was confirmed by H-1 NMR and GPC measurements.