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For the synthesis of a new biologically functional polymer from a natural resource by an environment-friendly method, the laccase-catalyzed polymerization of a lignin-based macromonomer, lignocatechol, was carried out for the first time in ethanol-phosphate buffer solvent system to give crosslinked polymers in good yields. Lignocatechol was prepared by the phase separation system of lignin and catechol in aqueous sulfuric acid. The copolymerization was also performed with urushiol to afford the corresponding copolymers in high yields. The polymerization mechanism was estimated by the IR and pyrolysis GC-MS measurements, suggesting that the polymerization proceeded mainly at the catechol ring through a quinone radical intermediate. The thermal properties were measured by the DSC, TG, and TMA analyses, indicating that the polymers had high thermal stabilities because of the crosslinked structures. In addition, it was found that the resulting polymers had the affinity of bovine serum albumin (BSA) and glucoamylase.

Peroxidase-catalyzed polymerization of lignin-based macromonomer, lignocresol, which was prepared by the phase-separation system of lignin and p-cresol in aqueous sulfuric acid, was carried out for the first time in aqueous organic solvents to give insoluble polymers in 55% yield. It was found that the polymerizability of lignocresol by peroxidase was enhanced by the introduction of p-cresol in lignin side-chains compared to that of original lignin. Copolymerization of lignocresol with p-cresol gave the corresponding copolymers in high yields. From the IR results, lignocresol might be polymerized through a phenoxyl radical. The pyrolysis gas chromatography-mass spectrometry (GC-MS) analysis of the polymers obtained indicated that the polymerization of lignocresol involved mainly the oxidative coupling at the introduced p-cresol. The thermal properties of the polymers obtained were characterized by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) measurements, suggesting that the polymers have high thermal stability according to the crosslinked structures. Copyright © 2005 John Wiley & Sons, Ltd.