The role of high-energy milling treatment for improving characteristics of areca leaf sheath lignin

Abstract This research examined the effects of high-energy milling (HEM) on the physicochemical and structural properties of lignin derived from the areca leaf sheath (ALS). Lignin was extracted from black liquor with the incorporation of 20 % phosphoric acid (H 3 PO 4 ), thereafter undergoing drying, grinding, and sieving to achieve a consistent powder. The characteristics of the lignin samples treated by HEM under regulated conditions were later examined using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and morphological analysis. FT-IR analysis indicated substantial changes in functional groups, implying partial depolymerization and heightened exposure of hydroxyl and carbonyl functionalities. The XRD patterns indicated a notable decrease in crystallinity, implying that mechanical forces during milling generated an amorphization impact. These structural disruptions may augment the reactivity and surface area of lignin, confirming that HEM is an effective physical method for modifying the characteristics of ALS-derived lignin. The findings support the increased use of agricultural leftovers using eco-friendly and sustainable processing techniques.