BRANCHED POLYMER-GRAFTED CARBON-BLACK WITH A HIGH PERCENTAGE OF GRAFTING - POSTGRAFTING OF POLYESTERS FROM GRAFTED POLYMER-CHAINS ON CARBON-BLACK SURFACE

To prepare a branched polymer-grafted carbon black with a high percentage of grafting, the postgrafting of polyesters from previously grafted polymer chain on the carbon black surface was investigated. For the initiation of postgraft polymerization from grafted polymer chains on the carbon black surface, poly(potassium acrylate) (PPA) and poly(styrene-co-PA) were grafted onto the carbon black surface by the polymerization and copolymerization of the corresponding vinyl monomers initiated by azo groups introduced onto the surface. The anionic ring-opening alternating copolymerizations of epoxides with cyclic acid anhydrides were successfully initiated by pendant potassium carboxylate groups of grafted PPA and poly(styrene-co-PA) on the carbon black surface. During the polymerization, the corresponding polyesters were effectively grafted from these grafted polymer chains to give branched polymer-grafted carbon black with a high percentage of grafting; the percentage of grafting of polyester onto PPA was determined to be 17.1 approximately 116.5%. The rate of the postgraft polymerization of epoxides with cyclic acid anhydrides and grafting of polyester were remarkably affected by the structure of grafted PPA and poly(styrene-co-PA) and by the solubility of these grafted polymer chains in the polymerization system. The branched polymer-grafted carbon black with a high percentage of grafting produced a stable colloidal dispersion in organic solvents.