摘要
以玉米秸秆为研究对象,分别采用5%H2SO4和5%NaOH溶液对秸秆进行解聚处理,并对解聚前后秸秆结构、化学组成、热稳定性等进行分析和表征。结果表明,与未处理前相比,经酸或碱解聚处理后,秸秆纤维结晶度由51.8%分别提高到63.5%和67.0%,秸秆中大部分半纤维素和部分木质素组分被脱除,半纤维素由29.10%分别降至7.02%和6.86%,木质素由38.12%分别降至32.21%和16.52%,而纤维素则由31.54%分别升至60.54%和76.15%。经酸碱处理后,秸秆表面形态结构变得疏松,出现小孔和裂缝,降解温度达到350℃,热稳定性能增加。上述结果说明,稀酸或稀碱均对玉米秸秆分子结构有一定程度的解聚作用,但就解聚溶出木质素而言,稀碱的解聚溶出效果要优于稀酸的。
The molecular structure of corn stalk after depolymerization with 5% H2SO~ or 5% NaOH solution was investigated. The change of structure, chemical composition and thermal property of corn stalk were comparatively analyzed and characterizated. The results showed that pretreatment with dilute acid or alkaline removed most of hemicellulose and some lignin in corn stalk as compared to those of the untreated stalk. The crystallinity of the depolymerized stalk were increased from 51.8% to 63.5% and 67.0%, the hemicellulose compositions were decreased from 29. 10% to 7.02% and 6.86% , the lignins from 38.12% to 32.21% and 16.52% , while the celluloses were increased from 31.54% to 60.51% and 76. 15% , respectively. After depolymerization corn stalk with acid or alkaline, the surface morphology of stalk become loose and appeared holes and cracks, the thermal stability increased and the degradation temperature reached over 350℃. These results suggest that dilute acid and alkaline have a certain depolymerization to the molecular structure of corn stalk, but the depolymerization effect of dilute alkali is better than that of dilute acid in terms of delignification.
出处
《化学通报》
CAS
CSCD
北大核心
2013年第7期645-649,共5页
Chemistry
基金
国家自然科学基金(21266023)
宁夏大学大学生科技创新与人文社会科学研究项目(12HGG14)资助
关键词
玉米秸秆
解聚
结构
酸碱
Corn stalk
Depolymerization
Structure
Acid-base
