One-step extraction of ramie cellulose fibers and reutilization of degumming solution

Ramie cellulose fibers are common natural fibers with high strength and outstanding biodegradability. However, there are interconnected gummy components covering raw ramie, which need to be removed to extract separated fibers. Here, an effective and environmentally friendly extraction approach using deep eutectic solvent (DES) was developed. The whole degumming technique can be completed in a one-step boiling process at 160°C for 2.5 h. This new method exhibited the capability to remove most non-cellulosic contents without sacrificing the physical properties or chemical structures of cellulose in comparison with the traditional alkaline method. Besides, the DES can be reutilized many times while still maintaining sufficient degumming efficiency. Some by-products in the degumming solution, such as lignin and polysaccharides, can be successfully separated, beneficially realizing recycling economy and sustainable development. The DES degumming method provides an alternative and practical method for ramie fiber extraction.