论文部分内容阅读
通过4种不同的改性方法:酯化、酰胺化、Schiff碱反应、硅烷化反应,对纤维素纳米晶(CNCs)进行巯基化改性,通过傅里叶变换红外光谱(FT-IR)和X射线光电子能谱(XPS)对其表面进行表征,采用透射电子显微镜(TEM)和X射线衍射(XRD)评价其物理性能,通过与Ellman’s试剂反应确定其巯基含量,依据元素分析中硫元素含量确定CNCs的取代度.由于具有:1)反应条件温和,如反应温度较低、反应时间较短以及用水作溶剂;2)能较好地保持CNCs棒状形貌和结晶度指数(巯基化CNCs 80.3%);3)较高的巯基含量(0.348 mmol/g)和取代度(0.224),Schiff碱反应是4种改性方法中较优的方法.
Through four different modification methods, such as esterification, amidation, Schiff base reaction and silylation, the cellulose nanocrystals (CNCs) were modified by thiolation and analyzed by Fourier transform infrared spectroscopy (FT-IR) and Its surface was characterized by X-ray photoelectron spectroscopy (XPS), its physical properties were evaluated by transmission electron microscopy (TEM) and X-ray diffraction (XRD), and its thiol content was determined by reaction with Ellman’s reagent. Determine the degree of substitution of CNCs due to: 1) mild reaction conditions, such as lower reaction temperature, shorter reaction time and use of water as a solvent; 2) able to better maintain CNCs rod morphology and crystallinity index (thiolated CNCs 80.3 %); 3) higher content of mercapto (0.348 mmol / g) and degree of substitution (0.224), Schiff base reaction is the best of the four modified methods.