废纸基纤维素纳米晶的制备与表征

Preparation and Characterization of Cellulose Nanocrystals from Waste Paper

中文关键词:  纤维素纳米晶（CNCs）  废纸  酸水解

Key Words:cellulose nanocrystals  waste paper  acid hydrolysis

中文摘要:

      以废纸为原料，采用传统硫酸法制备纤维素纳米晶（CNCs），并优化其工艺条件；采用傅里叶变换红外光谱仪（FT-IR）、X射线衍射仪（XRD）、热重分析仪（TGA）、透射电子显微镜（TEM）及扫描电子显微镜（SEM）研究了废纸基纤维素纳米晶（SCNCs）的结构与性质。在最佳工艺条件（硫酸浓度60 wt%、水解温度50℃、水解时间90 min）下，SCNCs的得率为41.2%，呈典型的纤维素Ⅰ型结构，结晶度为77.6%；与原料相比，几乎不存在杂峰；SCNCs为棒状结构，长约142.87 nm，直径约9.67 nm。探讨了回收硫酸溶液再次用于制备CNCs；结果表明，首次回收硫酸制备的废纸基纤维素纳米晶（SCNCs_H）得率为39.9%，结晶度为78.6%。

Abstract:

      In this paper, cellulose nanocrystals (CNCs) were prepared by traditional sulfuric acid hydrolysis of waste paper. The CNCs products were investigated by FT-IR spectroscopy (FT-IR), X-ray diffraction (XRD), thermal gravimetric analyzer (TGA), field emission scanning electron microscope (TEM), and scanning electron microscope (SEM). The optimum conditions for preparing SCNCs from waste paper were sulfuric acid concentration of 60 wt%, hydrolysis temperature of 50℃, and hydrolysis time of 90 min. Under this condition, the yield of SCNCs was 41.2%. The results suggested that the CNC products were typical cellulose I, and the corresponding crystallinity was 77.6%. There were almost no heterozygous peaks compared with raw material. The SCNCs products had a rod like structure, with a length of about 142.87 nm and a diameter of about 9.67 nm. At the same time, the possibility of recycling the acid solution for preparing SCNCs was also discussed. It showed that the yield of SCNCs prepared by the recycled acid solution was 39.9%, and the corresponding crystallinity was 78.6%, which was basically the same with the SCNC prepared by using original sulfuric acid.