Characterization of poly(D,L-lactide)/silica nanocomposites for food packaging application

Abstract

Currently PLA is used in food packaging application only for short shelf-life products, but designing the materials with exact properties provides many opportunities for PLA/nanocomposites for various food packaging applications. Properties of PLA can be improved by incorporation of nanoparticles into polymer matrix. Because of the small particle size and extremely high surface area, the incorporation of nanoparticles into a polymer matrix creates interphases and changes the intermolecular interaction of the matrix. As a result, by incorporation of only small amounts (less than 10 wt %) of nanofillers, a polymer nanocomposite can exhibit markedly improved physical and mechanical properties. The goal of this work was to investigate the potentials of PLA/silica nano composites for food packaging application. Neat PLA and PLA with 0.2, 0.5, 1, 2, 3 and 5 wt% of nanosilica were prepared by solution casting method in chloroform. Several procedures were used to experimentally characterize the PLA/nanocomposite samples. The size of the silica nanoparticles was measured by Zetananosizer. Differential scanning calorimeter (DSC) was used to measure the glass transition temperature (Tg) of the polymer nanocomposite samples. Thermogravimetric analysis was performed for investigation of thermal stability of all samples in inert atmosphere from 25°C to 600°C.