The aim of this work is the production of new biodegradable nanocomposites from polylactide (PLA), tetraethoxysilane (TEOS), and wood flour (WF) by means of an in-sihi sol-gel process and a melt blending method. Characterizations of SiO2, PLA, and hybrids were performed by FTIR, Si-29 solid-state NMR, XRD, DSC, TGA, and SEM analyses. As the results, the SiO2 can be well dispersed into the acrylic acid grafted polylactide (PLA-g-AA) in nanoscale sizes since the TEOS is partially compatible with PLA-g-AA and allows PLA-g-AA chains intercalating into SiO2 layers. Si-29 solid-state NMR analysis showed that Si atoms coordinated around SiO4 units were predominantly Q(3) and Q(4). The PLA-g-AA/SiO2 hybrid demonstrates dramatic enhancement in thermal and mechanical properties of PLA; for example, 80 degrees C and 20 MPa increases in IDT and TS with the addition of 10 Wt % SiO2 due to the formation of Si-O-C bond, and the nanoscale dispersion of silicate layers in the polymer matrix. On the basis of the consideration of thermal and mechanical properties, it is also found that 10 wt % of SiO2 content is optimal for preparation of PLA-g-AA/SiO2 nanocomposites. The biodegradable nanocomposites produced from our laboratory can provide a plateau tensile strength at break when the WF content is Lip to 50 wt %. (c) 2008 Wiley Periodicals, Inc.