胆碱类低共熔溶剂提取分离丝瓜络纤维素的研究

Extraction and Separation of Cellulose from Loofa Sponge with Two Types of Choline-based Deep Eutectic Solvents

分别采用氯化胆碱-尿素(ChCl-Ua)和氯化胆碱-草酸(ChCl-Oa) 2种胆碱类低共熔溶剂(DES)提取分离丝瓜络纤维素,探讨了这2种DES提取分离丝瓜络纤维素的工艺。结果表明,这2种DES对丝瓜络纤维素提取分离的效果具有显著差异,其中ChClOa DES提取分离丝瓜络纤维素的条件更温和、效果更佳,90℃下反应2. 5 h,丝瓜络的纤维素含量可增加到76. 41%,半纤维素和木质素的去除率分别为68. 4%和63. 9%。与未处理的丝瓜络相比,经过ChCl-Oa DES处理后的样品表面变得粗糙不规整,且内部纤维裸露可见。XRD分析结果表明,经这2种DES处理后的丝瓜络的纤维素结晶结构并未改变,仍为纤维素Ι型,但由于半纤维素、木质素、无定形纤维素等非晶部分的溶解,导致结晶度增大。

Cholin-based deep eutectic solvents （DESs）, featuring low cost, easy manufacture, nontoxicity and biodegradability, were used to extract and separate cellulose front loofa sponge. The effects of two different types of DES （i. e. ChCl-Ua DES ＆ ChC1-Oa DES） as well as different treatment conditions （e. g. temperature ＆ time） on the extraction and separation efficiency were studied. The results showed that ChCl-Oa acid DES had much higher extraction efficiency. The extracted cellulose content increased to 76.41%, the removul ratios of hemicellulose and lignin were up to 68.4% and 63.9% respectively for the sample treated with ChCl-Oa acid DES at 90℃ for 2. 5 h. SEM images showed rougher surfaces with exposed fibers for the samples treated with both DESs when compared with the untreated ones. XRD analysis indicated that the samples were still of cellulose type I but with higher crystullinity after DES treatment due to the dissolving of amorphous parts such as hemicellulose, lignin and amorphous cellulose.