超声波辅助碱-酸法提取蔗渣纤维素的研究

Study on extraction of cellulose from bagasse by ultrasonic assisted alkaline and acid treatment

以蔗渣为原料,采用超声波、碱性过氧化氢、乙酸溶液依次处理蔗渣获得蔗渣纤维素,通过正交试验确定优化提取工艺,借助傅里叶变换红外光谱仪(FTIR)、X射线衍射仪(XRD)及热重分析仪(TGA)对各处理阶段试样进行表征。结果表明,当超声波处理时间为15min,液固比为30∶1、NaOH质量分数为4%、H2O2体积分数为0.8%、温度为80℃、碱处理5h,酸处理4h时,提取的纤维素纯度最高为92.8%。提纯后的纤维素仍保持纤维素Ⅰ型结晶结构,结晶度为68.7%;其最大热解速率时的温度为353℃。

Cellulose was extracted from bagasse by ultrasonic wave,alkaline hydrogen peroxide and acetic acid.The extraction conditions were optimized by the orthogonal test.The products of each stage were characterized by Fourier transform infrared spectroscopy(FTIR),X-ray diffractrometer(XRD)and Thermogravimetric analyzer(TGA).The results showed that after ultrasonic treatment for 15 min,liquid-solid ratio of 30∶1,NaOH mass fraction of 4%,H2O2 volume fraction of 0.8%,heating temperature of 80℃,alkali treatment for 5 hand acid treatment for 4 h,the purity of extracted cellulose achieved 92.8%.The crystal structure of cellulose remained cellulose type I with68.7%crystallinity and the temperature at the maximal pyrolyzation rate was 353℃.