Controlled radical polymerization of styrene in the presence of different copper complexes and organic halides

The polymerization behaviors of Styrene (Sr) in the presence of CuX/L [X=Cl or Br; L = 2, 2'-bipyridine (bpy), 1,10-phenanthroline (phen) or 4,7-diphenyl-1,10-phenanthroline (DPP)] and R-X (R = trichloromethyl, benzyl or allyl; X = Cl or Br) have been studied and examined. In a CuCl/bpy/RCl/St system, a bimodal GPC peak at the early stage of polymerization was observed, and a concept of multi-active species was proposed to explain this phenomenon. In a CuCl/phen (DPP)/RCl/St system, the M-n of polystyrene (PS) increased linearly with St conversion and In [M](o)/[M] also increased linearly with time, indicating the 'living' nature of this system. Furthermore, the stability of the propagating active species in a CuBr/phen/RBr/St system is higher than that in the CuBr/phen/RBr/St system.