(a) Synthesis route of the click acetylation of cellulose. (b) FTIR spectra of CA. (c) 13C-NMR spectra of CA. (d) Effect of reaction time on the DS of CA synthesized in EmimAc with a molar ratio of 2.5 : 1 at room temperature. (e) Reaction conditions and results of the click acetylation of cellulose in RmimAc.