The component separation of coconut fiber by different mole ratio of ethylene glycol (EG) and ethylene carbonate (EC) with coconut fiber as raw material was studied at a low temperature of 90 ℃ in present study.Fourier transform infrared spectroscopy(FT-IR), X-ray diffraction(XRD), gel permeation chromatography(GPC) and thermogravimetry(TG) were used to analyze the isolated pretreated coconut fiber and regenerated lignin.The results showed the delignification rate was negative as the ethylene carbonate was individually applied;when the mole ratio of EG and EC was used by 4∶1, the maximal delignification rate was realized, represented 49.87%.It meant that the EG/EC could achieve the delignification pretreatment at a lower temperature.It was found that the isolated cellulose content by EG and EG/EC was increased and meanwhile, the corresponding hemicellulose and lignin contents decreased.Besides, the cellulose crystalline structure was not destroyed, and the lignin was typical p-hydroxy-guaiacyl-syringyl(HGS) lignin.%以椰壳纤维为原料,研究了不同比例乙二醇/碳酸乙烯酯在较低温(90 ℃)条件下对椰壳纤维的组分分离,并利用傅里叶变换红外光谱(FT-IR)、X射线衍射仪(XRD)、凝胶渗透色谱(GPC)和热重(TG)对分离得到的预处理后椰壳纤维和再生木质素进行了分析表征.结果表明:在单独使用碳酸乙烯酯时木质素的脱除率为负值,乙二醇/碳酸乙烯酯可实现椰壳纤维在较低温度下的去木质素预处理,并且当n(乙二醇)/n(碳酸乙烯酯)4∶1时木质素的脱除率达到最大值,为49.87%.乙二醇/碳酸乙烯酯处理后的纤维材料中纤维素含量都有所提高,半纤维素和木质素含量都降低,纤维素的结晶结构基本没有被破坏(均为纤维素Ⅰ型),且提取得到的再生木质素为典型的对羟基苯基-愈创木基-紫丁香基(HGS)型木质素,n(EG)/n(EC)为4∶1时得到的再生木质素多分散系数最小,为9.73.
展开▼
