Effect of Styrene/Initiator Ratios in Cp2TiCl Catalyzed Radical Polymerizations from Oxiranes, Carbonyls and Thermal Initiators

摘要

The ability of living radical polymerization (LRP) to control molecular weight and polydispersity via a reversible termination of propagating chains has enabled its wide applications in the synthesis of complex macromolecular structures. Catalytic systems based on late transition metal have proven very successful in LRP. Thus, atom transfer radical polymerization is accomplished by Cu, Ni, Fe, or Ru1,2 complexes while the organometallic dissociation-combination (DC) or degenerative transfer (DT) mechanisms are mediated by Co,3a Te,3b Sb3c and Mo.d These systems typically employ only activated halides or thermal initiators.a,b Thus, a broader initiators and catalyst selection will enlarge the synthetic scope of these polymerizations.