To investigate the effect of extractives and lignin on the thermal stability of wood flour (WF), thermogravimetric analysis was used to determine thermal degradation behavior of extracted and delignified mixed pine WF. The contribution of lignin to thermal stability was greater than that of extractives. Removing extractives resulted in improved thermal stability by increasing onset temperature T-0, and solvents with greater polarity contributed more to increasing T-0. However, solvent extraction had less effect on decomposition temperature (T-2) than did delignification, which significantly decreased T-2. A shoulder peak was observed only in delignified WF. Acetone/water extraction, hot-water extraction, and delignification are all significant model terms for variation in T-0; delignification is the most significant factor affecting T-0 and T-2. (C) 2014 Elsevier B.V. All rights reserved.