The Properties of Poly(lactic acid) Composites Reinforced by Silica Nanoparticles

Abstract

The series of PLA/SiO2 composites, containing 0.5-10 wt% nano-sized SiO2 (R805), were prepared by solution blending. The trade name of R805 is Aerosil R805. It is one of the silica nanoparticles products of Degussa. The resulting composites exhibit the higher glass transition temperature (Tg) than that of pure PLA. The Tg of composite showed a maximum increment of 7.8 ï‚°C by the addition of 5 wt% R805. The decomposition temperatures (Td) of composites were always higher than that of pure PLA and showed a maximum increment of 11 ï‚°C by the addition of 10 wt% R805. The water vapor transmission rate (WVTR) of composites are always lower than that of pure PLA and decreases with increasing SiO2 content to 5 wt% and then increases to 10 wt%. The WVTR of composite with 5 wt% SiO2 showed a 60% decrease compared to pure PLA. The Tg, Td, and water vapor barrier property are as a function of the SiO2 content.