麦草水溶性和碱溶性半纤维素的分离与表征  

Isolation and Characterization of Water-soluble and Alkali-soluble Hemicelluloses from Wheat Straw

作　　者：尉慰奇[1] 武书彬[1,2] 彭云云[1] 

机构地区：[1]华南理工大学制浆造纸工程国家重点实验室,广东广州510640 [2]中国科学院广州能源所可再生能源与天然气水合物重点实验室,广东广州510641

出　　处：《林产化学与工业》2010年第6期66-70,共5页Chemistry and Industry of Forest Products

基　　金：国家973计划资助(2007CB210201);国家863计划资助(2007AA05Z456)

摘　　要：采用水溶解和碱溶解法分离麦草半纤维素,并利用傅立叶红外光谱（FT-IR）、凝胶渗透色谱（GPC）、离子色谱、热重分析（TG/DTG）和核磁共振（NMR）研究了两种麦草半纤维素制备物的分子结构特征。结果表明：两种半纤维素制备物主要由阿拉伯糖木聚糖组成,此外还含有葡萄糖、半乳糖及葡萄糖醛酸和半乳糖醛酸,具有草类原料中典型的半纤维素结构。两种半纤维素制备物在20℃/min的升温速率下主要热失重区间都为200~330℃,其最大的热失重速率分别发生在282和313℃,碱溶性制备物的热稳定性比水溶性制备物略高。水溶性半纤维素是半纤维素中侧链取代度高、相对分子质量低与纤维素结合不紧密的部分,碱溶性半纤维素则刚好相反。The structural characteristics of wheat straw hemicelluloses isolated from water and alkali were investigated by FT-IR,GPC,ion chromatographys,TGA and NMR.The results show that wheat straw hemicellulose is composed mainly of L-arabino-D-xylans with minor quantities of galactose,glucose,glucuronic acid and glacuronic acid,which is a typical structure of straw hemicellulose.Under the 20 ℃/min heating rate,the mass loss of two wheat straw hemicelluloses mainly happened between 200 and 330 ℃,the maximum weight loss rate occurred at 282 and 313 ℃ respectively,the thermal stability of alkali-soluble preparation is slightly higher than that of water-soluble preparation.The result of GPC revealed that water-soluble preparation is the hemicellose with high substitution degree of side chain and relatively low molecular weight,while alkali-soluble preparation is just on the opposite.

关 键 词：麦草 半纤维素 红外 凝胶渗透色谱 离子色谱 热重分析 

分 类 号：TQ351[化学工程]