On the basis of former reports,C 60Cl n 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 C 60Cl n 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 C 60 and its derivatives.The results revealed that there is a new peak containing C 60 after coupling reaction between C 60Cl n 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 C 60Cl n.It was calculated that about two polystyrene chains are attached to a C 60Cl n molecule,and it demonstrated that two mechanisms,i.e.substitution reaction and addition reaction,have taken place simultaneously during the coupling reaction.
The fullerenes chloride,C 60 Cl n /C 70 Cl n, was used as a novel coupling agent in n BuLi initiated anionic polymerization of butadiene(Bd).Its coupling behavior was investigated by comparing with the commonly used coupling agent SiCl 4.The broader polydispersity of the coupling products and a new peak in GPC chromatograms demonstrated that coupling reactions happened and polybutadiene chains were covalently bonded to the molecule of C 60 Cl n /C 70 Cl n .But the coupling efficiency needs to be improved.The intrinsic viscosity of the coupling products([ η ]) was also measured.Double peaks in the coupling agent curves appeared when C 60 Cl n /C 70 Cl n was used,while a single peak in the coupling agent curves occurred when SiCl 4 was used.The results above showed that C 60 Cl n /C 70 Cl n had the specific coupling mechanisms which were different from SiCl 4.Two coupling mechanisms of C 60 Cl n /C 70 Cl n including addition and substitution were deduced.The experiment also revealed that in the anionic polymerization of Bd,the molecule C 60 could influence the polymerization.A new living center formed in the reaction system by n BuLi and C 60 might be able to initiate the polymerization of Bd,which increased the products’ molar mass and broadened polydispersity.The structure of the star shaped products with polybutadiene as arms and C 60 Cl n /C 70 Cl n as core should be studied further.
