茶渣微晶纤维素的制备及表征

摘要

Microcrystalline cellulose(MCC)was prepared from tea residue via acid hydrolysis method.Single factor tests and orthogonal experiments were performed to research on the effects of time, temperature, hydrochloric acid concentration and solid-to-liquid ratio on the yield, degree of polymerization(DP)and crystallinity of the MCC.The prepared MCC was also characterized by X-ray diffraction(XRD)and fourier transform infrared spectroscopy(FTIR).The results showed that the optimal conditions for MCC preparation were as follows:hydrolysis at 95℃for 90 min,at HCl concentration of 8 %(weight ratio)and 1:16 of solid-to-liquid ratio(g/mL),among which,the significance affecting on microcrystalline cellulose yield showed as time□HCl concentration□temperature□solid-to-liquid ratio.Under the optimal conditions,the yield of MCC reached to about 54.34 %.The DP of the MCC product was detected 128 and crystallinity was 67.77 % with crystallite sizes of 3.98 nm.The results obtained from FTIR analysis confirmed that chemical structure of the cellulosic fragments is not influenced by the acid hydrolysis.%以茶渣为原料,采用盐酸水解法制备茶渣微晶纤维素.通过单因素试验研究了酸解时间、酸解温度、盐酸浓度及料液比对微晶纤维素得率、聚合度和结晶度的影响,采用正交试验优化了工艺参数,并运用X-射线衍射和红外光谱对微晶纤维素产品进行表征.试验结果表明:最佳制备工艺条件为酸解温度95℃、盐酸质量分数8 %、酸解时间90 min、料液比1:16(g/mL).各因素对得率影响的显著性为:酸解温度>盐酸浓度>酸解时间>料液比;在此条件下,茶渣微晶纤维素产品的得率为54.34 %,聚合度为128;X-射线衍射和红外光谱分析表明,茶渣微晶纤维素与原纤维素材料结构一致,结晶度达67.77 %,晶粒尺寸为3.98 nm,晶型为纤维素Ⅰ型.