Acta Scientifica Malaysia (ASM)

This study evaluates bioplastic films produced from a 50:50 blend of acetylated and carboxymethylated cassava starch reinforced with kaolinite. The films were formulated with varying concentrations of glycerol (2–5 g) and kaolinite (0–1 g) which were subjected to soil burial test and thermal analysis (TGA/DTA). Unreinforced films with highest glycerol concentrations degraded fastest, showing up to 44.0% weight loss within one week owing to enhanced hydrophilicity and weaker intermolecular bonding while reinforced films recorded lower degradation, with values ranging between 20.00–36.50% depending on filler level. At constant glycerol content, biodegradability decreased with increasing kaolinite loading due to reduced microbial accessibility and improved structural integrity. Thermogravimetric analysis revealed three characteristic decomposition phases: initial moisture loss at 50–100 °C, major polymer degradation at 170– 225 °C, and final carbonaceous residue formation. Differential thermal analysis indicated glass transition temperatures (Tg) between 55–90 °C, decreasing with increasing glycerol content and slightly increasing with kaolinite incorporation. Reinforced films also displayed higher residual mass, confirming improved thermal stability. Overall, the acetylated and carboxymethylated starch blend exhibited high biodegradability and moderate-to-high thermal stability, with properties tunable through plasticizer and filler levels. The findings highlight the potential of dual-modified cassava starch films as promising eco-friendly alternatives to petroleum-based packaging materials.