Syntheses Of Branched Polystrene By Self-condensing Atom Transfer Radical Copolymerization

branched polystyrene was prepared by atom transfer radical polymerization ofstyrene with p-styrenesulfonyl chloride as the initiator. The molecular weights andmolecular weight distributions of the polymers obtained at different ratios of initiatorto monomer and different monomer conversions were determined by gel permeationchromatography. It was found that the molecular weights were higher than thecalculated ones by assuming that one polymer chain was generated perp-styrenesulfonyl chloride molecule, and that the molecular weight distributions werebroad with multi-peaks. The reactivity ratios for the conventional free radical copolymerization ofp-styrenesulfonyl choloride (M1) with methyl methacrylate (M2) were also determined.The compositions of p-styrenesulfonyl choloride -methyl methacrylate copolymerwere analyzed by H NMR spectra. Monomer reactivity ratios were calculated using 1three different methods, Fineman - Ross method, Kelen - Tudos method andYezrielev - Brokhina - Roskin method. The results are r1=2.438,r2=0.263(G-Hmethod) ; r1=3.004,r2=0.366(G'-H' method) from Fineman-Ross method, r1= 2.725,r2=0.319(G-H method);r1=2.712,r2=0.316(G'-H' method) from Kelen-Tudosmethod, and r1=2.703,r2=0.317 from Yezrielev-Brokhina-Roskin method.