Peroxidase-Catalyzed Oxidative Polymerization of Cresols to a New Family of Polyphenols

Enzymatic oxidative polymerization of cresols has been performed by using peroxidase catalyst in two types of polymerization solvent: an aqueous organic solution and a reverse micellar solution, to produce polymeric materials. Peroxidases derived from horseradish and soybean were employed as catalyst. The resulting polymers were partly soluble in DMF and DMSO, but, insoluble in water and other common organic solvents. The molecular weight of the DMF-soluble part was measured by GPC as ca. 5000. The solubility and molecular weight were dependent upon the polymerization condition and monomer structure. From IR and UV analyses, the polymer was found to be composed of a mixture of phenylene and oxyphenylene units. The polymer possessed no clear glass transition or melting points. TG analysis exhibited that the present polymers have relatively high thermal stability. The stability of the polymer from o- and m-cresols was better than that from the p-isomer. The polymer remained in around 40 weight % yield at 1000 °C under nitrogen.