GRAFTING POLYESTERS ONTO CARBON-BLACK .I. POLYMERIZATION OF BETA-PROPIOLACTONE INITIATED BY ALKALI-METAL CARBOXYLATE GROUP ON THE SURFACE OF CARBON-BLACK

In the reported experiments, by using carbon black that contained alkali metal carboxylate (-COOM; M equals Li, Na, K, Rb, or Cs) group as catalyst the anionic polymerization of beta -propiolactone (PL) was carried out at 50 degree C and the grafting of polyester onto the carbon black surface was investigated. Carbon black that contained -COOM group was prepared by the reaction of carboxyl group on the surface with corresponding alkali metal hydroxide and was able to initiate the anionic ring-opening polymerization of PL. The carbon black obtained from the reaction gave a stable colloidal dispersion in an organic solvent. It was confirmed that the polyester formed was grafted effectively onto the surface. Furthermore, the effect of alkali metal countercation (M** plus ) on the polymerization was studied. The initiating activity of -COOM group on the surface increased in the following order: -COOLi less than -COONa less than -COOK less than -COORb less than -COOCs. This order was in agreement with that of increasing electropositivity of these alkali metals.