Isolation of highly purity cellulose from wheat straw using a modified aqueous biphasic system

• Published in: Frontiers of chemical science and engineering Vol. 6; no. 3; pp. 282 - 291
• Main Authors: Yan, Lifeng, Zhao, Yi, Gu, Qing, Li, Wan
• Format: Journal Article
• Language: English
• Published: Heidelberg SP Higher Education Press 01.09.2012
• Subjects: Chemistry; Chemistry and Materials Science; Industrial Chemistry/Chemical Engineering; Nanotechnology; Research Article; straw; cellulose; separation; aqueous solution
• ISSN: 2095-0179; 2095-0187
• DOI: 10.1007/s11705-012-0901-5

Cellulose samples with molecular weights ranging from 8.39 × 10 4 to 11.00 × 10 4 g/mol were obtained from wheat straw. The dewaxed wheat straw was pretreated with aqueous hydrochloric acid followed by delignification using an environmentally benign poly (ethyleneglycol)/salt aqueous biphasic system. The yield of cellulose was in the range of 48.9%–55.5% and the cellulose contained 1.2%–3.2% hemicelluloses, and 0.97%–3.47% lignin. All the isolated cellulose samples could be directly dissolved in a 6 wt-% NaOH/4 wt-% urea aqueous solution through a precooling-thawing process to form a homogenous solution. The separation process was investigated and the obtained cellulose and its solution were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy and energy dispersive X-ray apparatus, and X-ray diffraction. The results revealed that aqueous soluble cellulose can be directly prepared from wheat straw by this method and this study opens a novel pathway to prepare cellulosic materials from agricultural waste.