Melting behaviour and dynamic mechanical properties of poly (lactic acid) - hemp - nanosilica composites

Poly(lactic acid)-hemp-nanosilica composites were prepared with a film stacking method. Melting behaviour of PLA composites was obtained using differential scanning calorimetry (DSC) and modulated-temperature DSC (mT-DSC). Crystallization and melting behaviour of the composites was studied in the range of 60-170 C at various heating rates with non-isothermal DSC. DSC results confirmed that the cold crystallization enthalpy gradually decreased corresponding with an increase in filler content. Multiple melting endotherms observed through mT-DSC were explained by a process of partial melting, recrystallization and remelting (mrr). The dynamic mechanical properties were determined via modulated force thermomechanometry. Better interfacial bonding was evidenced by an increased storage modulus with nanosilica addition, while the damping factor decreased respectively.