Improvement of wood polymer composite mechanical properties by direct fluorination

Highlights: • Direct fluorination was applied to wood flour, which was then used to process wood polymer composites. • Composite surface energy and hydrophilicity were reduced by fluorination. • Composite mechanical properties were enhanced by fluorination. - Abstract: Direct fluorination was applied to wood flour to enhance the mechanical properties of wood polyester composites by acting on the wood/polymer interfaces. X-ray tomography showed that this treatment decreased the quantity of pores within the composites. Tensile and flexural tests revealed an improvement of the composite properties through fluorination of the reinforcements. Both the elastic modulus and the strength were increased. The treatment also improved the creep properties of the wood–polyester composites, making them less sensitive to temperature. Furthermore, the composite surface energy and its hydrophilicity were decreased after the treatment of the wood reinforcements