Selkälä Tuula, Sirviö Juho Antti, Lorite Gabriela S, Liimatainen Henrikki
Fibre and Particle Engineering Research Unit, University of Oulu, P.O. Box 4300, FI-90014, Finland.
Microelectronics Research Unit, University of Oulu, P.O. Box 4500, FI-90014, Finland.
ChemSusChem. 2016 Nov 9;9(21):3074-3083. doi: 10.1002/cssc.201600903. Epub 2016 Oct 14.
Deep eutectic solvents (DESs) are green chemicals that have the potential to replace traditional solvents in chemical reactions. In this study, urea-LiCl DES was used successfully as a reaction medium in the anionic functionalization of wood cellulose with succinic anhydride. The effects of reaction temperature and time on the carboxyl content and yield were evaluated. The analyses of the degree of polymerization and crystallinity revealed that the DES was a nondegrading and nondissolving reaction medium. Three samples with the highest carboxyl contents were further nanofibrillated with a microfluidizer to diameters of 2-7 nm, as observed by atomic force microscopy. Samples treated at 70-80 °C for 2 h gave the best outcome and resulted in highly viscose and transparent gels. The sample treated at 90 °C contained larger nanoparticles and larger aggregates owing to the occurrence of possible side reactions but resulted in better thermal stability.
深共熔溶剂（DESs）是一类绿色化学品，有潜力在化学反应中替代传统溶剂。在本研究中，尿素-氯化锂深共熔溶剂成功用作木纤维素与琥珀酸酐进行阴离子功能化反应的介质。评估了反应温度和时间对羧基含量及产率的影响。聚合度和结晶度分析表明，该深共熔溶剂是一种不降解且不溶解的反应介质。通过原子力显微镜观察发现，对三个羧基含量最高的样品进一步用微流体化器处理，使其直径达到2 - 7纳米。在70 - 80°C处理2小时的样品效果最佳，得到了高粘性且透明的凝胶。在90°C处理的样品由于可能发生副反应而含有较大的纳米颗粒和较大的聚集体，但热稳定性更好。
