Synergic effect of basalt/wood fiber reinforced polylactic acid hybrid biocomposites against fungal decay

Abstract

In addition to the traditional fibre-reinforced composites, the investigation of novel composites with significant potential for engineering applications attracts increasing attention. In this study, the decay resistance of basalt and/or wood fibre-reinforced polylactic acid (PLA) biocomposites was evaluated with a soil block test by using white rot fungi, Trametes versicolor (Trv) and Irpex lacteus (Irl), and brown rot fungi, Poria placenta (Pop) and Gloeophyllum trabeum (Glt), and a soft rot fungus, Chaetomium globosum (Chg) after 8 weeks of water submersion. Water absorption rate during the water submission and weight losses after the decay test were determined. Furthermore, decay in biocomposites was characterized by SEM and ATR-FTIR. Results showed that the water absorption increased between 52.4-67.5% for wood fibre composites when compared to basalt fibre-reinforced biocomposites. PLA showed good decay resistance against all fungi attacks. However, as the ratio of basalt and wood fibre in the hybrid biocomposites increased, the fungi resistance decreased. The lowest weight loss, 4.9% was found in the biocomposites containing the highest percentage of basalt fibre. On the other hand, the highest weight loss, 54.2% was observed in the composites containing the highest percentage of wood fibre. The results clearly showed that the hybridization of basalt and wood fibres improves the decay resistance of the biocomposites compared to only wood fibre-reinforced composites. However, as the percentage of wood increased in the composites, the decay resistance decreased. SEM and FTIR analysis confirmed the degradation and revealed the degradation mechanism.