Abstract
<jats:p>Wood-plastic composites (WPCs) are mainly used in outdoor applications such as siding, outdoor furniture, decking, and window or door frames. However, outdoor conditions – including UV radiation, snow, rain, wind, and pollution – can deteriorate WPCs and shorten their service life. In this study, WPCs were coated with iron oxide (FeO) nanoparticles (NPs) reinforced recycled high-density polyethylene (rHDPE)-based films. The coated WPCs were exposed to natural weathering for 12 months. After the exposure, the thermal and fire properties of the WPCs were examined using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and limiting oxygen index (LOI) tests. The results showed that although the thermal degradation onset temperature of WPCs decreased after weathering, it remained higher due to the presence of FeO NPs. Extensive weathering conditions reduced the crystallization degree of WPCs. However, FeO NPs restrained the effects of outdoor conditions and limited the loss in crystallization degree. FeO NPs did not have a significant effect on fire resistance due to the intrinsic properties of metal oxide NPs. However, the fire resistance of FeO NPs reinforced film-coated WPCs was retained despite severe weathering conditions. FeO NPs loading did not have a significant effect on thermal and fire properties. The high thermal stability and fire resistance were provided by up to 3% loading of FeO NPs. Overall, under severe weathering conditions, iron oxide nanoparticles effectively enhanced both the thermal stability and fire behavior of WPCs</jats:p>