纳米微晶纤维素的提取及表面改性研究

Study on the Extraction and Surface Modification of Nanocrystalline Cellulose

以废旧棉织物为原料,通过机械粉碎、洗涤、碱煮、氧漂及酸水解等工艺,制备纳米微晶纤维素(NCC)。XRD证明其结晶度约为92%,通过扫描电镜观测,其纤维长度约为600～1000 nm,直径约为约为15～20 nm。通过硝酸铈铵的催化,在NCC表面接枝甲基丙烯酸甲酯(MMA)以改善其亲疏水性,并通过红外表征证实。接触角测试表明MMA接枝改性后的NCC其表面疏水性有明显改善。热稳定性测试表明,改性后的NCC热稳定性良好。

Nanocrystalline cellulose(NCC) was prepared from waste cotton fabrics by mechanical grinding, washing, alkali boiling, oxygen bleaching and acid hydrolysis. The crystallization property of NCC tested by XRD is about 92 %. By scanning electron microscopy(SEM) observation, the fibers lengths were about600~1000 nm, and the diameters were about 15 to 20 nm. Methyl methacrylate(MMA) was grafted on the NCC’s surface through ammonium ceric nitrate as a catalytic and verified by infrared characterization, which can improve NCC’s surface hydrophobic property. Contact Angle test showed surface hydrophobicity had obviously improved through surface modified by MMA grafted. Thermal stability test showed that the modified NCC had good thermal stability.