Investigation on the biological resistance of Beech (Fagus orientalis) wood and bark flour-polypropylene composites

In this study، the influence of using untreated bark flour، hot water and 1% sodium hydroxide treated bark flour as filler phase in lignocellulosic-plastic composites on biological and water absorption properties was investigated. The results of biological tests showed that untreated bark flour composites had higher biological durability in comparison with wood flour composites against brown rot fungi. Treatment of bark flour with hot water had no influence on the biological durability against either brown or white rot fungi. Treatment of bark flour with 1% sodium hydroxide resulted in a significant decrease in white rot weight loss and a considerable increase in brown rot weight loss. Water absorption test results indicated that the highest and least water absorption values after rotting with both brown and white rot fungi were in wood flour composites and sodium hydroxide treated bark flour composites، respectively. The water absorption values of the white rotted composites were higher than the brown rotted ones.