A toughened PLA/Nanosilica composite obtained in the presence of epoxidized soybean oil

Abstract

ABSTRACTIn this manuscript, a toughened PLA/nanosilica composite with good storage stability was obtained in the presence of the epoxidized soybean oil (ESO). The composite was fabricated via a twin‐screw extruder, and characterized by the FTIR, selective distribution test, and SEM. The surface of nanosilica was modified by the ESO through the chemical bonding, and this rendered the nanosilica to selectively localize in ESO droplets in the composite. As a result, the PLA/nanosilica composite was changed from brittleness to ductility with the addition of ESO. For example, the elongation and notched impact strength of the PLA/silica/ESO nanocomposite with 5 wt % nanosilica and 15 wt % ESO were ∼42% and ∼11 KJ/m2, respectively, which were much higher than neat PLA or PLA/nanosilica composite without ESO. Furthermore, the change of the brittle fracture of PLA into ductile fracture was investigated by SEM micrographs in detail. A possible toughening mechanism was also proposed. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41220.