期刊名称：Journal of Materials and Environmental Science
印刷版ISSN：2028-2508
出版年度：2017
卷号：8
期号：11
页码：4171-4181
出版社：University of Mohammed Premier Oujda
摘要：Pure cellulose crystals (CCs) have been successfully extracted from Tunisian almond shells using a combination of chemical treatments, such as alkaline treatment, bleaching, and sulfuric acid hydrolysis. The hydrolysis products of CCs without further dialysis have been thoroughly characterized. In this work, the chemical analysis of the raw materials revealed interesting levels of α-Cellulose content (29.9 wt%) and lignin content (30.1 wt%). Transmission electron microscopy showed that the sulfuric acid hydrolysis effectively isolated cellulose crystals at the nanometer scale. X-ray diffraction measurements and FTIR spectroscopy analysis confirmed that the isolated crystals are highly crystalline (67.50%) with a cellulose Iβ polymorphic form. The undialyzed CCs showed an apparent crystallite size about 5.66 nm. Thermogravimetric analysis demonstrated that the char yield of CCs, up to 630 °C, was higher than the untreated and pre-treated samples (showing a flame retardant behavior). This work confirms the great potential of undialyzed cellulose crystals for high-end applications.
关键词：Almond shell; natural polymer; cellulose crystals; acid hydrolysis; Dialysis;free process
