旧报纸基含木质素CNC和CNF的综合制备与表征

Integrated Preparation and Characterization of Lignin Containing Cellulose Nanocrystal and Nanofibril from Old Newspaper

关键词:  旧报纸  含木质素纤维素纳米晶体  含木质素纤维素纳米纤丝  综合制备

Key Words:old newspaper  lignin containing cellulose nanocrystal （LCNC）  lignin containing cellulose nanofibril （LCNF）  integrated preparation

摘要:本研究以旧报纸为原料，采用硫酸水解法制备了含木质素纤维素纳米晶体（LCNC），随后利用超声辅助球磨法将酸解沉淀的木质纤维素固体残渣（LCSR）解纤成含木质素纤维素纳米纤丝（LCNF），实现了LCNC和LCNF的综合制备，综合产率高达85%以上。采用多种手段对LCNC和LCNF样品的结构特性进行分析表征。结果表明，LCNC呈棒状晶体结构，LCNF呈长丝状结构，木质素以球状颗粒存在于LCNC和LCNF中。LCNC平均长度和宽度分别为143.6和24.8 nm，LCNF的平均直径为16.2 nm。X射线衍射仪（XRD）结果显示LCNC和LCNF均保留纤维素I型结构，且木质素含量越高，其结晶度越低。同时，木质素本身的高疏水性和热稳定性使得木质素含量大的LCNC和LCNF具有更好的疏水性和热稳定性。

Abstract:In this study， lignin containing cellulose nanocrystal （LCNC） was produced from old newspaper using sulfuric acid hydrolysis process， and then acidolysis precipitated lignocellulosic solid residues （LCSR） were mechanically defibrillated into lignin containing cellulose nanofibril （LCNF） by ultrasonic assisted grinding method， which realized the integrated preparation of LCNC and LCNF with overall yield more than 85%. The structural characteristics of LCNC and LCNF samples were characterized and the results showed that LCNC displayed rod-like crystal structure， while LCNF presented long filament structure. Lignin existed in LCNC and LCNF as globular-like particles. The average length and width of LCNC were 143.6 and 24.8 nm， respectively， and the average diameter of LCNF was 16.2 nm. XRD results demonstrated that the cellulose type I structure was still retained in all LCNC and LCNF， and the higher the content of lignin in the sample， the lower the crystallinity. Meanwhile， the high hydrophobicity and thermal stability of lignin made LCNC and LCNF with large lignin content had better hydrophobicity and thermal stability.