汉麻二粗纤维氮氧自由基/电化学脱胶研究

Nitronyl nitroxide radicals/electrochemical degumming system for hemp fiber

为降低汉麻二粗纤维提取的污染和成本,采用以电流作为共氧化剂激活的氮氧自由基体系进行脱胶。采用黏度法、束纤维强度测试、XRD、FTIR、SEM等技术分析脱胶后纤维的性能。结果表明:3种氮氧自由基的电氧化能力由强至弱的顺序为4-乙酰氨基-TEMPO、TEMPO、4-OH-TEMPO;使用质子交换膜后纤维残余木质素含量率低了14.62%,且扫描速度对脱胶效果的影响较小;最佳反应条件为4-乙酰氨基-TEMPO 0.8 g/L,p H值11.0,时间80 min,温度80℃。该条件下制得纤维的失重率为17.83%,残余木质素质量分数为2.9%,白度为46.3,断裂强度为987 N/g。

To reduce the environment pollution and cost of hemp fiber extraction, nitronyl nitroxide free radical system activated by currents as co-oxidant is used for hemp degumming. Viscometry, fiber boundles tenacity, XRD, FTIR, SEM, etc. are used to analyze the property of fiber after degumming. Results show that the order of the electro oxidation ability of the three nitroxide radicals from strong to weak is 4-acetylamino-TEMPO, TEMPO, 4-OH-TEMPO. The use of proton exchange membrane could reduce the residual lignin content by 14.62%, and scaning speed has little influence on degumming effect. Under optimal degumming conditions of reaction at 80 ℃ for 80 min with 4-amino-TEMP of 0.8 g/L and pH of 11.0, the weight loss of the fiber is 17.83%, residual lignin content is 2.9%, the whiteness is 46.3, and the breaking strength is 987 N/g.