Physical properties and crystallization behavior of silica particulates reinforced poly(lactic acid) composites

The objective of this study is to fabricate the PLA/SiO2 composites and to investigate the effect of silica nanoparticles on the toughness improvement and thermal resistance of PLA. The tensile properties and impact resistance of the resulting PLA/SiO2 composites were estimated. Furthermore, the heat deflection temperature, thermomechanical properties, crystallization behavior, and thermal stability improvement of the PLA/SiO2 composites were also evaluated. The nano-silica in less than 1.5 wt.% can increase the Youngʹs modulus, elongation at break, Izod impact strength, and heat deflection temperature of the PLA/SiO2 composites by about 21.7%, 267%, 227%, and 25 °C, respectively, compared to those of the neat PLA. The inclusion of nano-silica can also increase the crystallinities of the PLA/SiO2 composites with a simultaneous decrease in spherulite dimension. Furthermore, the PLA/SiO2 composite with 1.5 wt.% silica content can improve its thermal stability by nearly 20 °C in thermal degradation temperature.