Grafting onto carbon black by the reaction of reactive carbon black having epoxide groups with several polymers

The grafting of functional polymers onto carbon black surface by the reaction of epoxide groups introduced onto the surface was investigated. The introduction of epoxide groups was achieved by the reaction of the phenolic hydroxyl and carboxyl groups on carbon black with chloromethyloxirane in the presence of sodium hydroxide. The amount of epoxide groups introduced onto the channel black Neospectra II was equal to 0.40 meq/g. The epoxide groups were reacted with polypropylene glycol, silicone diol (SDO), silicone diamine (SDA), and polyethyleneimine to give polymer-grafted carbon blacks. For example, the percentage of grafting of SDO (M_n = 1.0 × 10³) and SDA (M_n = 3.9 × 10³) reached to 23.6 and 67.2%, respectively. The percentage of grafting increased with the molecular weight (M_n) of the polymers, while the number of grafted chain (G_n) decreased. In the case of SDO, the relationship between M_n and G_n was found to be G_n = 4.68 × 10^?2 M. The carbon black obtained from the reaction gave stable colloidal dispersions in tetrahydrofuran and the stability of dispersion increased with an increase in the percentage of grafting.