In situ fabrication of wood flour/nano silica hybrid and its application in polypropylene‐based wood‐plastic composites

Wood‐plastic composites are attracting great interest from society due to their recycling nature and excellent processability. Also, nano silica can be used as reinforcing filler for wood‐plastic composites. However, it is difficult to achieve a fine nano silica dispersion within the wood‐plastic composites. In this article, the alkali treatment and sol‐gel method were combined to modify the wood flour(WF) in situ to prepare WF/silica hybrid, and the hybrid was used as reinforcing filler for polypropylene‐based wood‐plastic composites. The physicochemical properties of WF/silica hybrid were characterized by infrared spectroscopy, scanning electron microscopy and thermogravimetric analysis. Subsequently, the mechanical properties, Vicat softening temperature, oxidation induction time and thermal decomposition behavior of polypropylene‐based wood‐plastic composites were characterized. The test results were compared with polypropylene‐based wood‐plastic composites blended with nano silica. Compared with the wood‐plastic composites blended with commercial silica, the composites filled with hybrid filler have better mechanical performances and thermal stability. The addition of hybrid is also beneficial to improving the thermal oxygen resistance of the composites. We envision that the present work offers novel insights to prepare high‐performance wood‐plastic composites.