Thermomechanical Properties and Thermal Behavior of Poly(Lactic Acid) Composites Reinforced with TiO2 Nanofiller

Abstract

The reinforcement effect of nanofiller in polymer enhanced the thermal stability, physical and mechanical properties of poly (lactic acid) (PLA) composites with good reinforcing capabilities for bio-based polymers. In this paper, the effect of reinforcement of titanium dioxide (TiO2) nanofiller on the mechanical properties and thermal behavior of PLA matrix are reported. PLA/TiO2 nanocomposites with different percentages of 2.0, 3.5, 5.0 and 7.0 %∙w/w were prepared by using solvent casting method and hot press machine. TiO2 were dispersed in PLA matrix using mechanical mixer and ultrasonication technique. The mechanical properties and thermal behavior of PLA nanocomposites were characterized using dynamic mechanical analysis (DMA) and differential scanning calorimeter (DSC). The increased in storage modulus by the addition of nanofiller with the highest increment provided by 2.0 %·w/w TiO2 indicated a strong influence and better interfacial bonding between nanofiller and PLA matrix. An increased in storage modulus started at 100 °C that linked to the cold crystallization (Tcc) of PLA composites is in agreement with DSC result. The Tcc shifted to higher temperature as the content of nanofiller increased and this result were observed at 2.0 %·w/w of the nanofiller content. Reinforcement of nanofiller increased the melting temperature from lower filler loading until 5.0 %·w/w. The incorporation of TiO2 nanofiller as the reinforcement agent for PLA has a potential in biopolymer medical engineering and packaging industry, a highly competitive application with a great demand of cost and performance.