Characterization of <i>Tinospora Cordifolia</i> Stem Particulates as a Functional Filler for Sustainable Composites

Particulate fillers from plant waste are of increasing interest due to their low price, availability, and antimicrobial activities. In this study, Tinospora Cordifolia stems were processed through crushing followed by ball milling, resulting in particulates with an average size of 21.97 µm. The Tinospora Cordifolia stem particulates (TCSP) were characterized through FTIR, XRD, thermal analysis, NMR, SEM, AFM, WCA, and antimicrobial test. Chemical analysis revealed a low density (0.8 g/cm3), moderate cellulose (45.65%) and lignin (17.12%) content, minimal hemicellulose (3.70%), and wax (0.034%), imparting lightweight, thermally stable, and mechanical properties. FTIR confirmed cellulose and lignin through O–H, C–H, C=C, and C–O vibrations, while XRD showed mixed cellulose phases (I, II, IV) with a crystallinity index of 30.59% and crystallite size of 4.61 nm. TGA results showed a high Tmax of 319.87°C and an activation energy of 64.65 kJ/mol, ensuring thermal stability. SEM and AFM analyses demonstrated a rough, irregular fibrous surface of TCSP with a Ra of 41.469 nm and negative skewness. Water Contact angle values of 67.6°–75.4° indicated moderate hydrophilicity. Importantly, TCSP exhibited strong antibacterial activity, with inhibition zones of 15.2 mm (E. coli) and 18.4 mm (B. cereus), attributed to phytochemicals.