Milling in Seconds Accelerates Acetylation of Cellulose in Hours

A new sustainable synthetic method for cellulose acetate was developed by a combination of I₂-catalyzed solid-liquid acetylation of cellulose and a milling process reducing the crystallinity of cellulose within a few seconds. Milled low-crystalline cellulose was acetylated faster than the original cellulose with higher crystallinity. The plausible factors of acceleration were the conversion of the hydroxy group in hydrogen bonds into reactive ones and the efficient formation of the catalytic species I⁺ by the enhanced formation of I₃ ^- assisted by the amorphous domain of the milled cellulose, while the morphological and structural changes were ignorable.