A Survey on biodegradation, hardness and dimensional stability of a hybrid composite of wood flour / polypropylene / glass fiber in different circumstances

In this study, the effect of cellar fungus (brown rot fungus) conophora cerabella on biodegradability, hardness and dimensional stability of wood flour/polypropylene/glass fiber hybride composites after suffering ambient conditions (immersion in water) were studied. So, the samples by 40 to 60, 50 to 50 and 60 to 40 percent of wood flour / PP weight ratios respectively and three levels of glass fibers 0,10 and 15 weight percent were made. The Samples, immersed in water at 25 and 40°c, sea water and pool water for 1608 hours and then exposed to the cellar fungus for 6 weeks. The results showed, by increasing the wood flour weight ratio and Adding glass fiber to composite samples, those weight loss due to fungal attack, increased and decreased respectively. Overall, after immersion in water compared to control, the samples had greater weight loss and the samples that immersed in pool water and hot water of 40°c, compared to others, showed greater amounts of weight loss. With the increase of wood flour weight ratio and adding the glass fiber in hybrid composite, the samples hardness were increased. Overall, after soaking in water, compared to controls, the test samples showed lower hardness. By increasing the wood flour ratio in composites, the water absorption and thickness swelling amount, were increased. Adding glass fiber to composites in all ratios of wood flour, caused to reduction and controlling of water absorption and thickness swelling.