The chemo-enzymatic modification and degumming of hemp fiber by the laccase-2,2,6,6-tetramethylpiperidine-1-oxyl radical-hemicellulase system and physico-chemical properties of the products

In this study, we found an environmentally friendly system in the degumming of hemp fiber without using a strong acid and alkali. The chemo-enzymatic modification and degumming of hemp fiber used an acetic acid–sodium acetate buffer solution containing laccase, hemicellulase and 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO) under a mild condition (pH = 5, T = 50℃). Through comparing and analyzing the physical and chemical properties of fiber products under different treatments, we found the method involving treatment with TEMPO/laccase/hemicellulase not only greatly removed most of the gum attached on the surface of the raw hemp fiber, but also introduced surface-active aldehyde and carboxyl groups into the fiber. The performances of the hemp fibers with different treatments were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy and X-ray diffraction. We also found the product was finer, with a lower content of non-cellulosic components and it had better water uptake properties (moisture sorption and water retention value), which has potential application values in textile industries.