Evaluation of wood-polyethylene composites biodegradability caused by filamentous fungi

•The mycelial growth of different soft-rot fungi on WPCs were analyzed.•Aspergillus niger, Trichoderma reesei, and Chaetomium globosum were most effective, with highest growth rate.•The impact of Aspergillus niger on WPCs surface (signs of deterioration) and material changes were observed.•The rate of biodegradation of the analyzed WPCs according to the amounts and type of wood filler.•Most susceptible to biodegradation are WPCs with deciduous flour, the greatest resistance show WPCs with coniferous flour.

This study describes the impact of filamentous fungi on wood-polymer composites (WPCs) containing various types of fillers (coniferous, deciduous, cellulose) in the amount of 30 wt.% to 50 wt.%. The selection of fungal strain of filamentous fungi was performed prior to the study on the impact of the wood type on the progress of WPCs biodegradability. The changes associated with various water absorption of the examined WPCs, were observed using scanning electron microscopy (SEM). The impact of fungal mycelium, which had affected the changes in WPCs material, was examined using thermogravimetric analysis (TG). The results showed, that the growth of mycelium on WPCs, influenced mainly the temperature of decomposition and carbonization in wood fillers. Moreover, the measurements of analyzed fillers and composite materials, conducted by the use of FTIR/ATR technique (attenuated total reflectance Fourier transform infrared spectroscopy), have proved the existence of relevant structural differences, as well as qualitative and quantitative changes, which are depended on the amount and the type of the filler. Therefore, the rate of biodegradation of WPCs seems to be adequate to the processes of initial changes, caused in this material by the growth of filamentous fungi.