Coupling effect of C60Cln on anionic living polystyrene and on polystyrene-b-polyisoprene block copolymer

On the basis of former reports, C60Cln was used as a novel coupling agent to react with active polymer chains in anionic polymerization of styrene and copolymerization of styrene and isoprene initiated by n- BuLi, respectively. The UV-Vis spectra of coupling products showed that C60Cln was bonded to the polymer chain. The various samples were analyzed by GPC using a refractive index (RI) detector and an ultraviolet (UV) detector set at 340 nm for the absorption of C60 and its derivatives. The results revealed that there is a new peak containing C60 after coupling reaction between C60Cln and polymer chains, and the polydispersity of the coupling products is broadened, which demonstrated that coupling reaction has taken place and polymer chains are covalently bonded to the molecule of C60Cln. It was calculated that about two polystyrene chains are attached to a C 60Cln molecule, and it demonstrated that two mechanisms, i.e. substitution reaction and addition reaction, have taken place simultaneously during the coupling reaction.