High-efficiency organosolv degumming of ramie fiber by autocatalysis of high-boiling alcohols: an evaluation study of solvents

Ramie was subjected to degumming treatment with high-boiling alcohols, which was an innovative way ahead ascribed to organosolv’s innate superiorities, namely the capability to dissolve non-cellulosic biomass obtaining separation of high-purity cellulose fibers, as well as green and ease of recovery. In the current research, effects of degumming processes with four sorts of alcohol solvents on the ramie fiber properties [degree of polymerization (DP), tenacity, linear density] and the possibility of reutilization of degumming solution were studied. Results showed that the organosolv degumming process efficiently removed non-cellulosic components and improved the DP value. In terms of the degummed fibers, except 1,4-butanediol treated fibers due to the serious damage of 1,4-butanediol to fibers, the cellulose purity was over 95%, the tenacity was 6.14–8.27 cN/dtex, and the linear density was less than 7.2 dtex. Besides, glycol treated fibers performed the most positive mechanical properties (8.27 cN/dtex) and glycerol treated fibers showed the lowest residual gum content (3.28%). Notably, the fiber still showed excellent performance after the sixth cycle treatment with glycerol, that was 3.62% of residual gum content and 4.45 cN/dtex of tenacity, which fully met the requirement of spinning process. Considering attractive characteristics of eco-friendly, high degumming efficiency, outstanding performances, and solvent recycling, this emerging method could inspire the potential application of alcohols for natural fiber isolation. Graphic abstract