Grafting of polyesters onto carbon black. III. Polymerization of β-propiolactone initiated by quaternary ammonium carboxylate groups on the surface of carbon black

By use of carbon black containing quaternary ammonium carboxylate (COO^?N⁺R₄) groups as catalyst, the anionic ring opening polymerization of β-propiolactone (PL) was carried out at 50°C. Although carbon black itself was unable to initiate the polymerization of PL, carbon black containing COO^?N⁺R₄ groups, which was prepared by the reaction of carboxyl groups with corresponding quaternary ammonium hydroxide, was found to be able to initiate the polymerization. The carbon black obtained from the polymerization gave a stable colloidal dispersion in an organic solvent, and it was confirmed that the polyester formed was effectively grafted onto the surface. In addition, the effect of quaternary ammonium countercation on the polymerization was investigated.