Use of functionalized organocobalt initiators in processes of emulsion polymerization

Characteristics of novel organocobalt–tridentate Schiff base chelates bearing a heteroatomic group capable of donating an electron couple, namely amino or hydroxyl function, or the carboxylate anion, at the terminal position of an alkyl ligand, are reported in respect to their presumable application as initiators of radical polymerization. These processes were studied in water emulsions using styrene as a model monomer at various pH and temperatures. Polymerization rates proved relatively low if both the length of carbon chain of the alkyl ligand and pH range favored extra chelation in the given initiator due to coordination of the functional group. With this reservation, the complexes in question act as highly effective pH-dependent initiators of emulsion polymerization, by general analogy with the corresponding non-functionalized initiators. Characteristics of the polymer products, including latexes, are presented and discussed.