Fabrication of microcellular polylactide/modified silica nanocomposite foams

Abstract

Microcellular polylactide (PLA)/modified-silica (m-silica) nanocomposite foams were prepared in a batch process using supercritical carbon dioxide as physical blowing agent. To enhance the dispersion in the PLA matrix, silica nanoparticles were modified by dodecyltrichlorosilane) and were melt compounded with PLA using a twin-screw extruder. PLA/m-silica nanocomposites with m-silica contents of 0.5, 1, 2, 3, and 5 wt % were obtained. The incorporation of m-silica nanoparticles in PLA enhanced the thermal and mechanical properties of PLA. The resultant foams were observed by scanning electron microscopy (SEM) and average cell diameter and cell density were calculated using SEM micrographs. The incorporation of m-silica nanoparticles into the PLA matrix had the effect of decreasing the cell diameter and increasing the cell uniformity and cell density.