Thermal properties and flammability of polylactide nanocomposites with aluminum trihydrate and organoclay

Biodegradable polylactide (PLA) nanocomposites with aluminum trihydrate (ATH) and modified montmorillonite (MMT) were prepared via direct melt compounding using a twin-screw micro extruder. The exfoliated and intercalated structures of clay in the matrix were observed by TEM and XRD. The thermal oxidative degradation temperature and activation energy of the PLA/ATH/MMT nanocomposite determined by thermogravimetric analysis are higher than that without addition of ATH and organoclay. The incorporation of layered silicates into the PLA/ATH composite results in further stabilization throughout the degradation step. The V-0 rating (UL94 V) of the PLA nanocomposite has been achieved, and the melt dripping was reduced during combustion. Results showed that high loading of the conventional flame retardant ATH yielded brittle PLA composites; however, replacing a portion of the ATH with modified MMT in the PLA matrix improved this result.