Synthesis and characterizations of poly(ethylene oxide) methyl ether grafted on the expanded graphite with isocyanate groups

Introducing isocyanate (NCO) groups onto the surface of expanded graphite (EG) was achieved by treatment of the EG with excess toluene-2,4-diisocyanate in dimethyl sulfoxide (DMSO). The reaction of NCO group on the EG with the hydroxyl group in the poly(ethylene oxide) methyl ether (MPEO) to yield MPEO-grafted EG was carried out for modifying the surface properties of graphite. The influence factors, such as reaction time, temperature and the ratio of the reactants, on the grafting reaction and grafting ratio were investigated.