玉米秸秆皮、髓纤维素提取及表征

Extraction and Characterization of Cellulose from Corn Straw Bark and Pith

关键词:  玉米秸秆  秸秆皮、髓  纤维素  纯化

Key Words:corn straw  corn straw bark and pith  cellulose  purification

摘要:以玉米秸秆为原料，研究玉米秸秆皮、髓纤维素的性质。玉米秸秆皮、髓分别用苯-醇抽提后，进一步用亚氯酸钠在酸性环境下脱除木质素，最后用氢氧化钾脱除多戊糖，得到玉米秸秆皮、髓纯化纤维素。结果表明，秸秆皮中纤维束排列更整齐紧密，秸秆皮和髓化学组分相似。从秸秆皮、髓得到的纯化纤维素得率分别为38.9%和38.2%，其中α-纤维素含量为87.5%和82.4%，绝大多数多戊糖和木质素被脱除。秸秆皮、髓纯化纤维素的晶型结构仍为纤维素I型，结晶度由纯化前的51.2%和30.4%提高到67.7%和42.1%；纯化纤维素的起始分解温度和最高分解温度相对于秸秆皮、髓均提高，热稳定性优于玉米秸秆皮、髓。

Abstract:Corn straw was used as raw material to study the properties of cellulose in the bark and pith of corn straw. The purified cellulose from corn straw bark and pith was obtained by extracting the bark and pith with benzene-ethanol， respectively， and further removing lignin with sodium chlorite under acidic environment， and finally removing pentosane by potassium hydroxide. The results showed that the fiber bundles in the straw bark were more neatly and tightly arranged， and the chemical fractions of straw bark and pith were similar. The yield of purified cellulose from corn straw bark and pith were 38.9% and 38.2%， respectively， of which the α-cellulose content was 87.5% and 82.4%， respectively， and most of pentosane and lignin were removed. The crystalline structure of purified cellulose from straw bark and pith was still cellulose type I. Compared with corn straw bark and pith before purification， the crystallinity of purified cellulose increased from 51.2% and 30.4% to 67.7% and 42.1%， respectively. The starting and maximum decomposition temperatures of purified cellulose were increased compared with those of straw bark and pith， and the thermal stability was better than that of corn straw bark and pith.