Fabrication ZnO functionalized nano-montmorillonite for enhancing the fire-safety and mechanical properties of wood flour/poly (vinyl chloride) composites

The synthesis of a novel flame retardant that can enhance fire-safety while maintaining or even improving the mechanical properties is crucial for the application of wood flour/polyvinyl chloride composites (WF/PVC). Here, the alginate-derived tactic was utilized to produce zinc oxide (ZnO) in situ on the surface of montmorillonite (MMT) nanosheet, and an original type of MMT@ZnO nanosheet was synthesized. Then, MMT@ZnO nanosheet was incorporated into the WF/PVC. The experimental results confirmed that the incorporation of MMT@ZnO nanosheet in WF/PVC simultaneously improves the flame retardancy and mechanical properties. Comparing with the WF/PVC, WF/PVC containing 6 wt% MMT@ZnO nanosheets (WF/PVCMZ-6) reduced the total heat release rate, and total smoke production by 30.1% and 32.2%, respectively. Encouragingly, the WF/PVCMZ-6 exhibited a significant increase of 24.6% in tensile strength and 36.8% in flexural strength. This work develops a biomass alginate-derived strategy to combine ZnO and two-dimensional MMT nanosheets that simultaneously enhance the mechanical performance and flame retardancy of WF/PVC for the construction field.