Enhanced properties of poly(lactic acid) with silica nanoparticles

The objective of this article is to fabricate poly(lactic acid) (PLA) and nano silica (SiO2) composites and investigate effect of SiO2 on the properties of PLA composites. Surface-grafting modification was used in this study by grafting 3-Glycidoxypropyltrimethoxysilane (KH-560) onto the surface of silica nanoparticles. The surface-grafting reaction was confirmed by Fourier transform infrared spectroscopy and thermogravimetric analysis. Then the hydrophilic silica nanoparticles became hydrophobic and dispersed homogeneously in PLA matrix. Scanning electron microscope and Dynamic thermomechanical analysis (DMA) results revealed that the compatibility between PLA and SiO2 was improved. Differential scanning calorimetry and polarized optical microscope tests showed that nano-silica had a good effect on crystallization of PLA. The transparency analysis showed an increase in transparency of PLA, which had great benefit for the application of PLA. The thermal stability, fire resistance, and mechanical properties were also enhanced because of the addition of nano silica particles. Copyright (c) 2016 John Wiley & Sons, Ltd.