超声波辅助对甲苯磺酸催化水解纸浆制纳米纤维素晶体

Preparation of Nanocrystalline Cellulose by the Catalytic Hydrolysis of Pulp with p-Toluenesulfonic Acid Under Ultrasonication

利用对甲苯磺酸催化水解硫酸盐竹浆,制备了一种新型高效、绿色环保的纳米纤维素晶体(NCC),分析了反应时间、反应温度和超声波的作用对NCC得率及性能的影响,并采用傅里叶变换红外光谱(FT-IR),X-射线衍射(XRD),透射电镜(TEM)以及热重分析(TGA)对NCC谱学性能、晶体结构、形貌特征以及热稳定性进行了表征。研究结果表明:在反应时间45 min、反应温度80 ℃,超声波作用时间2 h的条件下,NCC得率(51.66%)最高;TEM显示NCC直径为10~40 nm,长度为400~700 nm;XRD分析得知NCC结晶度为 72.50%,较原料(硫酸盐竹浆)有所提升,二者均为纤维素Ι型;TGA表明NCC热学性能较原料稳定。

A new type of high-efficiency and environmentally-friendly NCC was prepared by the catalytic hydrolysis of fiber raw material with p -toluenesulfonic acid. The effects of reaction time, reaction temperature and ultrasonication on the yield and properties of NCC were investigated. Fourier transform infrared spectroscopy(FT-IR), X-ray diffraction(XRD), transmission electron microscopy(TEM) and thermal gravimetric analysis(TGA) were used to characterize the spectral properties, crystal structure, morphology and thermal stability.The results showed that the NCC yield was the highest(51.66%) at the condition of reaction time of 45 min, reaction temperature of 80 ℃ and ultrasonic wave time 2 h. The TEM results indicated that the diameters of NCC were 10 to 40 nm and the lengths were 400 to 700 nm. XRD analysis showed that the crystallinity of NCC was 72.50%, which was higher than that of fiber raw material, and both of them maintained cellulose Ι structure.TGA displayed that the thermal properties of NCC were more stable than raw fiber.