稀盐酸预处理结合高压射流方法制备微纤化纤维素的研究

Preparation of microfibrillated cellulose by dilute hydrochloric acid pretreatment and high pressure jet micronization

应用稀盐酸预处理结合高压射流超微粉碎方法开展微纤化纤维素制备的实验研究,检测了产物的微观形态、粒径分布、结晶度、热稳定性以及薄膜样品的拉伸性能。实验结果表明,经过稀盐酸预处理和高压射流超微粉碎处理,纤维素微纤束直径从几至几十微米下降至几十至几百纳米,微纤束长度约从百微米级降至微米级;经6%HCL预处理和高压射流处理(130 MPa,1次),样品粒径指标D50从93μm降为14μm。纤维素原样经HCL和高压射流处理后结晶度小幅减小和热稳定性基本保持不变,薄膜样品的拉伸性能极大提高,以6%HCL结合高压射流(130 MPa,4次)处理获得的薄膜样品拉伸性能最优,其拉伸强度平均为20.41 MPa,断裂伸长率平均为7.93%,弹性模量平均为322 MPa。

The preparation of microfibrillated cellulose by dilute hydrochloric acid pretreatment and high pressure jet micronization was studied.The microstructure,size distribution,crystallinity and thermal stability of the samples were explored.Experimental results show that the diameter of cellulose microfibrils decreased from several or dozens of microns to dozens or hundreds of nanometers and the length of cellulose microfibrils decreased from hundreds of microns to several of microns.The particle size index D50 of the samples treated by 6%HCL and high pressure jet micronization(130 MPa,1 pass)decreased from 93μm to 14μm.After treated by dilute hydrochloric acid and high pressure jet micronization,crystallinity of all samples was lower and thermal stability of the samples was fundamentally unchanged.Actually,the tensile properties of film samples were greatly improved.The tensile properties of film samples prepared by 6%HCL hydrochloric acid and high pressure jet micronization(130 MPa,4 pass)were the best.Its average tensile strength was 20.41 MPa,average elongation was 7.93%,and average modulus of elasticity was 322 MPa.