The physical and chemical properties of hemp fiber prepared by alkaline pectinase–xylanase system

Abstract

Degumming is the vital and critical step in the preparation of hemp fiber for textile application. However, the traditional chemical degumming processes use large amounts of harmful chemicals, especially strong alkalis, which have caused severe challenges to the environment. The reaction conditions of alkaline pectinase and alkaline pectinase were studied in this research, and the alkaline pectinase-xylanase system was successfully applied to the degumming of hemp fibers in mild conditions (T = 55 °Cand pH = 8.0) without strong alkali. A comparative analysis of hemp fibers treated under different conditions showed that the alkaline pectinase-xylanase system degummed up to about 50% gum removal within 5.5 h, making the fibers smoother and stronger. After alkaline pectinase-xylanase system treatment (0.6 g pectinase, 0.3 g xylanase, 55 °C, pH 8.0, 5.5 h), the removal ratio of pectin and hemicellulose reached 75% and 40%, respectively. And linear density and tenacity of the fiber were 17.4 dtex and 5.62 cN/dtex, respectively. SEM, FT-IR and XRD analysis furthermore demonstrated the excellent effects of the proposed process. The degumming fiber had better water retention performance (513%) and moisture sorption (8.9%), which has more excellent application prospects in the textile industry. Moreover, the method abandons the use of acid and alkali and can provide an eco-friendly degumming process for hemp fiber.Graphical abstract