Combined effect of water uptake and temperature on wood polymer composites

Wood polymer composites are materials frequently used for outdoor applications, since they can operate under a large range of temperature and moisture conditions. The present work investigates the combined effect of water soaking and temperature (ranging from 10 up to 40 °C) on wood flour filled high density polyethylene. Water soaking tests have revealed that the percentage of absorbed water at the saturation plateau increases with temperature due to the induced stiffness reduction of the polymeric matrix. This hypothesis has been confirmed by scanning electron microscopy analyses, which has allowed to observe the filler–matrix interface and to measure the wood flour particle size. In addition, instrumented Charpy impact tests have shown a strong toughness reduction as a consequence of fiber–matrix debonding induced by particle swelling, which worsens with temperature. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46674.