OXIDATIVE POLYMERIZATION OF PHENYLENEDIAMINES CATALYZED BY HORSERADISH-PEROXIDASE

Ortho-, meta-, and para-phenylenediamines were polymerized using hydro gen peroxide as an oxidant and horseradish peroxidase as a catalyst in mixed solvents of 1,4-dioxane and water. The yield of the polymers wa s strongly dependent on solvent composition, and maximum yields were o btained at 15-30% 1,4-dioxane. The analysis of circular dichroic spect ra of the enzyme suggested that enzyme structure was significantly mod ified at high 1,4-dioxane contents, which may be responsible for the d ecrease of catalytic activity of the enzyme. On the basis of IR and el ectronic spectra of the polymers, it was considered that o- and p-phen ylenediamine polymers retain disubstituted benzene nuclei, which sugge sts that the polymerization proceeded mainly via N-N coupling. (C) 199 8 John Wiley & Sons, Inc.