Flame retardancy, antifungal efficacies, and physical-mechanical properties for wood/polymer composites containing zinc borate

This work aimed to examine flame retardancy, antifungal performance and physical-mechanical properties for silane-treated wood-polymer composites (WPCs) containing zinc borate (ZnB). ZnB with content from 0.0 to 7.0wt% was added to WPCs, and silane-treated wood contents were varied. The polymers used were poly(vinyl chloride) (PVC) and high-density polyethylene (HDPE). The decay test was performed according to the European standard EN 113. Loweporus sp., a white-rot fungus, was used for antifungal performance evaluation. Antifungal performance was observed to decrease with wood content. Incorporation of ZnB at 1.0wt% significantly increased the antifungal performance of WPCs. ZnB content of greater than 1.0wt% lowered the antifungal properties of WPCs. The results suggested that the wood/PVC composite exhibited better antifungal performance than the wood/HDPE composite. The addition of wood flour to PVC and HDPE decreased flame retardancy, whereas the incorporation of ZnB retained the flame retardancy. ZnB was found to be more appropriate for wood/PVC than wood/HDPE as a result of hydrogen chloride generated from the dehydrochlorination reaction of PVC. The results indicated that the addition of ZnB did not affect the physical-mechanical properties of neat polymers and the composites. Copyright (c) 2016 John Wiley & Sons, Ltd.