Poly (lactic acid) (PLA)/clay/wood nanocomposites

Poly (lactic acid) (PLA) is a promising substitute for conventional petroleum-based polymer materials as a result of its environmentally benign quality and suitable physical properties. However, there are also problems associated with properties, such as brittleness, low heat deflection temperature, low melt viscosity, as well as cost that prevent wide-range applications of PLA.;This work reports on melt extrusion preparation of PLA/clay/wood nanocomposites involving various compatibilizers, resulting in remarkable improvements in mechanical as well as in thermal material properties. In particular, the tensile and flexural moduli of PLA/clay/wood nanocomposites with 30 wt. % wood flour and 5 wt. % nanoclay respectively increased from 3.75 to 7.08 GPa and from 3.83 to 6.01 GPa compared to neat PLA. The thermal decomposition temperature improved by about 10°C compared to that of PLA/wood composites.;A mathematical model was developed based on Eshelby's equivalent inclusion method and Mori-Tanaka's background analysis to successfully predict longitudinal elastic moduli of complex structured nanocomposite materials.