Grafting of polymers onto vapor grown carbon fiber surface by ligand-exchange reaction of ferrocene moieties of polymer with polycondensed aromatic rings of the wall-surface

To improve the dispersibility of vapor grown carbon fiber (VGCF) in solvents, the grafting of copolymer containing vinyl ferrocene (VFE) onto the surface by ligand-exchange reaction between ferrocene moieties of the copolymer and polycondensed aromatic rings of VGCF was investigated. The copolymer containing VFE was prepared by the radical copolymerization of VFE with methyl methacrylate (MMA) using 2, 2′-azobisisobutyronitrole as an initiator. It was found that by heating of VGCF with poly(VFE-co-MMA) in the presence of AlCl₃ and Al powder, the copolymer was grafted onto the wall-surface: the percentage of grafting reached to 57.5%. It is considered that the copolymer was grafted onto VGCF surface by ligand-exchange reaction between ferrocene moieties of the copolymer and polycondensed aromatic rings of VGCF. In addition, carboxyl groups were successfully introduced onto VGCF wall-surface by the ligand-exchange reaction of 1,1′-dicarboxyferrocene with VGCF in the presence of AlCl₃ and Al powder. The carboxyl groups on VGCF were reacted with hydroxyl-terminated polymers to give the corresponding polymer-grafted VGCF. The polymer-grafted VGCF gave a stable colloidal dispersion in solvents for grafted polymer. The electric properties of composite prepared from polymer-grafted VGCF in solvent vapor were investigated.