Influence of Concentration of Compatibilizer on Long- term Water Absorption and Thickness Swelling Behavior of Polypropylene, Wood Flour/Glass Fiber Hybrid Composites

The influence of concentration (2، 3 and 5%) of Maleic Anhydride Grafted Polypropylene (MAPP) on long term water absorption and thickness swelling of wood flour/E-glass fiber Hybrid polypropylene composites were studied. The samples (strips with 10 mm thickness and 70 mm width) were made using a laboratory twin-screw extruder. Long term water absorption and thickness swelling kinetics of manufactured hybrid composites were evaluated by immersing them in water at room temperature for several weeks. Water diffusion coefficients and thickness swelling parameter (KSR) were calculated by evaluating the water absorption isotherms. The results showed that increase in MAPP content to 2 and 5% significantly decrease maximum water absorption، thickness swelling، water diffusion coefficients and KSR of the composites. Water diffusion coefficient of the studied composites was proved to follow the kinetics of a Fickian diffusion process.