Structure and properties of the graft copolymer of starch and p-hydroxybenzoic acid using horseradish peroxidase

Abstract

A modified starch tannage was synthesized by free radical graft copolymerization of degraded starch with p-hydroxybenzoic acid (pHA) using horseradish peroxidase/H 2O 2 as the initiator. In this study, the effects of the degree of degradation of the starch, dosage of pHA, polymerization temperature, system pH, and horseradish peroxidase content on the tanning properties of the graft copolymer were investigated. The shrinkage temperature of leather tanned by the graft copolymer was 78°C. The thickness increment ratio of the retanned leather was 21.6%, and meanwhile the retanned leather showed better softness. The results indicate that the graft copolymer has excellent tanning and retanning properties. The structure of the graft copolymer was analyzed by Fourier Transform Infrared Spectroscopy (FTIR), 1Hydrogen-Nuclear Magnetic Resonance ( 1H-NMR), and 13Carbon-Nuclear Magnetic Resonance ( 13C-NMR) and Gel Permeation Chromatography (GPC). Compared with conventional methods, we show that a "green" leather tannage could be achieved using a radical graft copolymerization of starch and phenols. © 2011 John Wiley & Sons, Ltd.