金属离子催化纤维素酸水解制备微晶纤维素的研究

Study on Hydrolysis of Cellulose for Preparation of Microcrystalline Cellulose Catalyzed by Metal Ions

本文以漂白阔叶木浆为原料,研究了制备微晶纤维素过程中不同金属离子对纤维素酸水反应的催化作用,并采用X射线衍射图谱(XRD)、扫描电镜(SEM)等方法对水解纤维素进行了分析和表征。结果表明,添加Fe3+、Al3+、Cu2+和Co2+有利于促进纤维素的酸水解反应,其中Fe3+的催化作用最佳;当Fe3+的浓度为0.3mol/L时,水解纤维素的得率为91.27%,聚合度为166,达到了微晶纤维素的极限聚合度;XRD分析表明,添加Fe3+更有利于纤维素无定形区的选择性酸水解,提高水解纤维素的结晶度。

The bleached hardwood kraft pulp （BHKP） was used as raw material to investigate the acid hydrolysis of cellulose by adding metal ions as catalyst in the preparation of microcrystalline cellulose. The properties of hydrocellulose were characterized by X-ray diffraction （XRD） and scanning electronic microscope （SEM）, etc. The resuits showed that the Fe^3＋ , Al^3＋, Cu^2＋ and Co^2＋ were helpful for the hydrolysis of cellulose and the FeC13 showed better catalytic ability than the others. When the concentration of FeCl3 was 0. 3 mol/L, the yield of hydrocellulose was 91.27%, and the degree of polymerization （DP） was 166 which reached the level-off degree of polymerization （LODP）. XRD results indicated that the Fe^3＋ was more advantageous to improve the selectivity of acid hydrolysis of amorphous area of cellulose, which resulted in a high crystallinity of hydrocellulose.