Acetylated cellulose nanocrystals with high-crystallinity obtained by one-step reaction from the traditional acetylation of cellulose

One-step reaction instead of two-step or multi-step reaction is simple and feasible to prepare the acetylated cellulose nanocrystals (ACNCs). Herein, a common and moderate one-step reaction for obtaining the acetylated cellulose nanocrystals (ACNCs) with high-crystallinity via traditional acetylation of cellulose is first proposed. Morphology property analysis indicates that ACNCs with a rod-like structure have a length of 21-140 nm and a width of 12-20 nm. The ACNCs show an allomorph of cellulose II with a high-crystallinity of similar to 70%. C-13 NMR and FT-IR analysis indicate that the obtained ACNCs have been acetylated, and the DS of ACNC-1.5 and ACNC-2.0 are 0.18 and 0.42, respectively. By studying the reaction mechanism, it can be found that ACNCs were obtained in the synergetic process of hydrolysis and acetylation. They can be redispersed in both water and organic solvent systems. This study provides a simple new method to prepare the acetylated CNCs with high crystallinity.