Improved durability of lignocellulose-polypropylene composites manufactured using twin-screw extrusion

The objective of this study was to investigate the use of peat as a potential lignocellulose source in composites manufactured by twin-screw extrusion. The effects of peat decomposition rate and particle size on the mechanical properties and moisture resistance of peat-polypropylene (PP) composites under cyclic conditions were evaluated. The properties of the peat-PP composites were compared to commercial lignocellulosic fibre products, namely wood-plastic composite (WPC), medium density fibreboard (MDF) and hardboard (HB). The results show that prior cyclic freeze-thaw testing peat-PP composites had properties equal to commercial WPC, but their mechanical permanence was better after freeze-thaw conditioning. When moderately decomposed, smaller particle-size peat was used, peat-PP composites had better dimensional stability, though particle size did not affect as much as the decomposition degree. Thus, the chemical structure of peat has a greater influence on composite durability, as better water and weather resistance are achieved with peat that is more decomposed.