Full-Component Acetylation of Corncob Residue into Acetone-Dissolvable Composite Resin by Titanium Oxysulfate Reagent

Herein, all components of corncob residues were acetylated to synthesize an acetone-soluble resin material. Moreover, titanium oxysulfate (TiOSO4), a low-cost intermediate for the industrial production of TiO2, was first used as an acetylation reagent. Through optimizing reagent dosages and reaction times, above 90% of hydroxyl groups in the corncob residue can be substituted by acetyl groups. During the acetylation reaction, TiOSO4 was transformed into TiO2 and uniformly distributed within the acetylated corncob residue. The resulting product, owing to its solubility in acetone, can be employed to fabricate a composite film with excellent mechanical properties, achieving an increase of 85% in tensile strength and 90% in strain rate compared to commercial cellulose acetate film. By this preparation technique, the industrial-grade corncob residue as raw material can be converted to acetylated composite films. Further analysis indicates that the coexistence of acetylated lignin and TiO2 plays a pivotal role in enhancing the mechanical properties of acetylated corncob residue composite film. Additionally, this material exhibits substantial degradation within 28 days under natural environmental conditions, whereas commercial cellulose acetate shows no significant changes even after 60 days. The present achievements are a significant breakthrough in the high-value technologies for the conversion of corncob residues.