通过一步反应对纤维素纳米纤维进行磺化后处理以提高其分散性。
Post-sulfonation of cellulose nanofibrils with a one-step reaction to improve dispersibility.
机构信息
School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA; Renewable Bioproducts Institute, Georgia Institute of Technology, Atlanta, GA, USA.
School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA; Renewable Bioproducts Institute, Georgia Institute of Technology, Atlanta, GA, USA; The Forest Products Laboratory, US Forest Service, Madison, WI 53726, USA.
出版信息
Carbohydr Polym. 2018 Feb 1;181:247-255. doi: 10.1016/j.carbpol.2017.10.077. Epub 2017 Oct 23.
Cellulose nanofibrils (CNF) were sulfonated and the dispersion quality was compared to unfunctionalized and 2,2,6,6-tetramethylpiperdine-1-oxyl radical (TEMPO) post-oxidation treatment of existing CNF (mechanically fibrillated pulp). A post-sulfonation treatment on existing CNF in chlorosulfonic acid and dimethylformamide (DMF) resulted in sulfonated CNF that retained a fibril-like morphology. There was a small decrease in the cellulose crystallinity index for the sulfonated CNF, but this was much lower than the reported regioselective oxidative bisulfite pretreatment method used to make sulfonated CNF. The current approach was extremely quick, and 5min of reaction time was sufficient to result in significant improvements in dispersibility compared to unfunctionalized CNF. The sulfonated CNF and TEMPO oxidized CNF had better dispersibility compared to the unfunctionalized CNF when dispersed in DMF and water, and in many cases the sulfonated CNF had better dispersibility than the TEMPO CNF. It was found that when CNF was dispersed in DMF the TEMPO CNF formed carboxyl dimethylammonium groups, while the sulfonated CNF formed formate groups.
纤维素纳米纤维（CNF）进行磺化处理，并将其分散质量与未功能化和 2,2,6,6-四甲基哌啶-1-氧自由基（TEMPO）后氧化处理的现有 CNF（机械纤维纸浆）进行比较。在氯磺酸和二甲基甲酰胺（DMF）中对现有 CNF 进行后磺化处理，得到了保留纤维状形态的磺化 CNF。磺化 CNF 的纤维素结晶度指数略有下降，但远低于报道的用于制备磺化 CNF 的区域选择性亚硫酸氢盐预处理方法。目前的方法非常快速，只需 5 分钟的反应时间，就可以显著提高与未功能化 CNF 相比的分散性。磺化 CNF 和 TEMPO 氧化 CNF 在 DMF 和水中的分散性优于未功能化 CNF，在许多情况下，磺化 CNF 的分散性优于 TEMPO CNF。结果发现，当 CNF 在 DMF 中分散时，TEMPO CNF 形成了羧基二甲铵基团，而磺化 CNF 形成了甲酸盐基团。
Zotero 插件