Enzymatic oxidative polymerization of 2,6-dimethylphenol has been carried out in an aqueous organic solvent at room temperature under air. Laccase derived from Pycnoporus coccineous and horseradish and soybean peroxidases were active for the polymerization, yielding polymeric materials with molecular weights of several thousands. The product polymer was in all cases soluble in common organic solvents. The polymerization behavior was dependent on the enzyme type. The effects of the solvent composition have been systematically investigated with respect to the polymer yield and molecular weight. The mixing ratio between the organic solvent and buffer affected the polymer yield, and the highest yield was achieved in 60% buffer. Various water-miscible organic solvents such as acetone, methanol, and 1,4-dioxane were available as components of the mixed solvent. In using laccase catalyst, the acidic buffer afforded the polymer in high yields. NMR and matrix-assisted laser desorption/ionization time of flight mass spectroscopic analyses showed that the present polymer was exclusively composed of 2,6-dimethyl-1,4-oxyphenylene units.

: Enzymatic oxidative polymerization of 4-hydroxybenzoic acid derivatives using oxidoreductases has been carried out in an aqueous organic solvent at room temperature under air. The monomers used in this study were 4-hydroxybenzoic acid, 3,5-dimethoxy-4-hydroxybenzoic acid (syringic acid) and 3,5-dimethyl-4-hydroxybenzoic acid. The latter two monomers were subjected to oxidative polymerization using horseradish peroxidase (HRP), which involved elimination of carbon dioxide and hydrogen from the monomer to produce poly(1,4-oxyphenylene). Oxidoreductases, soybean and Coprinus cinerius peroxidases, Pycnoporus coccineus and Myceliophthore laccases, were active for the polymerization and the enzyme type and its origin greatly a †ected the polymerization behaviour. The e †ects of solvent composition have been systematically investigated with respect to polymer yield and molecular weight. In the case of HRP-catalysed polymerization of syringic acid, the highest molecular weight (1É5 ] 104) was achieved in acetone/phosphate bu †er (pH 7) (40 : 60 vol%). NMR, IR and matrix-assisted laser desorption/ionizationÈtime of Ñight mass spectroscopic analyses of the polymer showed that the present polymer consisted made exclusively of 1,4-oxyphenylene unit and that the terminal structure was a carboxylic acid group at one end and a phenolic hydroxyl group at the other.of Chemical Industry ( 1998 Society Polym. Int. 47, 295È301 (1998)

Enzymatic oxidative polymerization of phenol has been carried out in an aqueous organic solvent using horseradish peroxidase as catalyst. The polymerization in a mixture of 1,4-dioxane and phosphate buffer (pH 7.0) (80 : 20 vol%) produced powdery polymeric materials, which were partly soluble in DMF and DMSO. The molecular weight of the DMF-soluble part determined by GPC was 3.5 × 104. Polymerization conditions have been investigated with respect to the polymer yield, solubility, and molecular weight. The solvent composition enormously affected the polymerization. The polymer structure was estimated by IR and NMR spectroscopies and found to contain a mixture of phenylene and oxyphenylene units. From TG analysis, the polymer was found to possess high thermal stability; 43 weight % of the polymer remained up to 1000 °C under nitrogen. DSC measurement showed no clear glass transition temperature or melting point.

Enzymatic oxidative polymerization of p‐alkylphenols using horseradish peroxidase as catalyst has been carried out in two polymerization solvent systems: a mixture of phosphate buffer (pH 7) and 1,4‐dioxane, and a reverse micellar solution, yielding powdery polymeric materials. The polymer yield was much dependent upon the type of alkyl group in the monomer as well as the solvent type. In case of the polymerization of umbranched alkylphenols in the aqueous 1,4‐dioxane, the polymer yield increased with increasing chain length of the alkyl group from 1 to 5, and the yield of the polymer from hexyl or heptylphenol was almost the same as that of the pentyl derivative. The relationship between the type of substituent and the polymer yield in the reverse micellar system was different from that in the aqueous 1,4‐dioxane; the highest yield was achieved from ethylphenol. The resulting polymers had molecular weight of several thousands. The polymer was estimated to be composed from a mixture of phenylene and oxyphenylene units from IR analyses. TG measurement exhibited that the polymer had relatively high thermal stability. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 1453–1459, 1997

SUMMARY Enzymatic oxidative polymerization of bisphenol-A was carried out in an aqueous organic solvent using horseradish and soybean peroxidases (HRP and SBP, respectively) as catalysts. The SBP-catalyzed polymerization in an equivolume mixture of methanol and phosphate buffer (pH 7.0) affords a new class of polyphenol quantitatively, which is readily soluble in polar organic solvents such as acetone, methanol, N,Ndimethylformamide, and dimethyl sulfoxide, but insoluble in chloroform, diethyl ether, and water. NMR and IR analyses show that the polymer is mainly composed of a mixture of phenylene and oxyphenylene units. The effects of the type of enzyme and the solvent composition were systematically investigated in respect to the yield and molecular weight of the polymer. The thermal treatment of the polymer produces an insoluble product and the curing temperature and the molecular weight of the starting polymer affect the thermal properties of the product. Crosslinking reaction of the present polyphenol with an epoxide resin affords insoluble polymeric material showing high thermal stability.