A Facile Method to Manufacture the Sesamum Indicum Fibers by Glycolic Acid Assisted with Microwave

The Sesamum indicum bast contains more hemicellulose, lignin, and flaky parenchymal cells than the commonly used ramie bast, which are rigid for the degumming process. We explored a facile and greener method by using glycolic acid microwave-assisted treatment combined with alkaline treatment to effectively and low-cost prepare the high-quality Sesamum indicum single fibers. The chemical and physical properties of fibers were analyzed by chemical composition analysis, SEM, FTIR, XRD, TG, and GPC analysis. The residual gum content was decreased from 34.4% to 4.2%, resulting in a cleaner micro-surface of the Sesamum indicum fibers with increased cellulose crystallinity (75.2%–82.5%) and thermal stability (357°C–365°C). The fiber fineness (2.5 dtex) and breaking tenacity (4.9 cN/dtex) of the fibers produced by the novel treatment method exhibited the same level compared with the traditional two-step alkaline fibers. Besides, both the consumption of water and the chemicals was decreased compared with traditional degumming. This work provided a novel green and facile degumming method for processing the natural bast fibers.