Determination of biological performance, dimensional stability, mechanical and thermal properties of wood-plastic composites produced from recycled chromated copper arsenate-treated wood

The aim of this study was to investigate the dimensional stability, mechanical and biological performance and thermal degradation of wood-plastic composites made from high-density polyethylene and recycled wood treated with chromated copper arsenate (CCA), a commonly used wood preservative chemical. Virgin pine wood samples were also prepared with and without a coupling agent and used as the control group. Samples of CCA-treated Scots pine (Pinus sylvestris L.) with varying wood content were produced by adding different ratios of the coupling agent. The recycled CCA-treated wood-filled composites exhibited better flexural and tensile strength properties and dimensional stability than the control group, whilst their impact strength was less. Biological test values showed improved durability against termites and fungus with the recycled CCA-treated wood-filled composites. In addition, the leaching of heavy metals was significantly diminished when the coupling agent was utilized at a level of 5% (w/w), thus presenting a much lower impact on the environment.