关键词: 龙须草, 纤维素, 分离, 结构, 结晶度, 热分析

Abstract:

The cellulose of Eulaliopsis binata was prepared by delignification with sodium chlorite followed by ultrasonic irradiation and then by extraction with alkali.Effect of extraction methods on the properties of cellulose obtained was investigated and their structure characterized by FTIR, Xray diffraction and thermal analysis.The results showed that the product prepared by extraction with 8% and 10% NaOH is of the highest purity, the content of cellulose is 91.3%, average degree of polymerization was 1949, molecular weight was 315685.All the cellulose products are of typical cellulose I structure.The sequential extraction by higher KOH and NaOH concentration(15% and 18%)in shorter time(2 h )or by lower KOH and NaOH concentration(8% and 10%)in longer time(12 h)leads to crystallinity decrease of cellulose products.The thermal stability is better for the cellulose obtained by twostep sequential extractions with 8% and 10% than the others.If treatment method was the same,the thermal stability is better for the cellulose obtained by extraction with NaOH than for the sample by extraction with KOH.

Key words: 龙须草, 纤维素, 分离, 结构, 结晶度, 热分析