<p>The highly crystalline nature and poor solubility of microcrystalline cellulose (MCC) limit its further development. To broaden the potential applications of MCC, this research endeavors to enhance its properties by covalently grafting gallic acid (GA) onto the MCC structure through a chemical grafting technique. This procedure resulted in the development of gallic acid-microcrystalline cellulose ester (CELL-GA) derivatives. Through single-factor tests and response surface optimization experiments, the optimal synthetic pathways of the intermediates were explored, and the properties of both the intermediates and final products were characterized. The findings demonstrate that the optimal reaction parameters consist of a reaction temperature of 60℃, a reaction duration of 4&#xa0;h, and a molar ratio of sulfuryl chloride (SOCl₂) to triacetylgallic acid (Ac-GA) of 5:1. Under these specified conditions, the yield of triacetylgalloyl chloride (Ac-GA-Cl) reached 86.9%, which closely aligns with the predicted value. Proton nuclear magnetic resonance (¹H NMR) spectroscopy verified that the integral ratios of the three hydrogen atoms in the molecular structures of both Ac-GA and Ac-GA-Cl corresponded closely to their theoretical values, thereby confirming the successful synthesis of these compounds. Furthermore, X-ray diffraction (XRD) and thermogravimetric analysis (TG) indicated that CELL-GA exhibited a marked decrease in crystallinity relative to MCC, accompanied by an 85℃ reduction in thermal decomposition temperature. This decline is attributed to the grafting of gallic acid, which disrupts the intermolecular hydrogen bonding within MCC, thereby disturbing its ordered crystalline domains and consequently reducing both the crystallinity and thermal stability of the resultant material.</p>