Thermal Decomposition Kinetics of Modified Ammonium Polyphosphate/Rice Husk Flame‐Retardant Polylactic Acid: Synergistic Reduction of Activation Energy and Enhanced Flame Retardancy
Mingyang Liu, Ziheng Zhang, Hengyu Liu, Dongming Shi, Jingzu Li, Qinglei Liu, Jilai Ying, Yufeng Sun, Ing KongABSTRACT
The flame‐retardant mechanism and activation energy correlation in degradable natural fiber/polymer composites remain unclear. This study investigates polylactic acid (PLA) reinforced with silane‐modified ammonium polyphosphate (KAPP) and rice husk (RH) using multiscale thermodynamic analysis. Results show lower activation energy leads to higher flame‐retardant efficiency. Kinetic analyses confirmed that the KA‐5 composite has the lowest activation energy due to earlier decomposition. The silane coupling agent improved APP dispersion, promoting early phosphoric acid release, catalyzing char formation, and releasing diluting/nonflammable gases. This synergistic effect elevated the LOI of KA‐5 to 28.9% (UL‐94 V‐0), demonstrating that low activation energy underlies high flame‐retardant efficiency.