Effect of Filler Content and Compatibilizer on Thermal Properties of Wood Flour - HDPE Composites

In this study, the effect of filler content and compatibilizer on thermal properties of wood flour - high density polyethylene (HDPE) composites was investigated. To meet this objective, HDPE and wood flour (50, 60 and 70 wt %) with coupling agent (0, 2 and 4 wt %) were compounded in an internal mixer, and samples were fabricated by injection molding. Thermal properties and fractional crystallinity of samples were studied by thermogravimetric analysis (TGA) and differential scanning calorimetriy (DSC). The lower weight loss at higher temperature was found for composites containing higher amount of wood flour; Also, the thermal properties of composite samples increased with the increasing of wood flour up to loading fraction of 60%, but decreased using higher (70) wood flour loading fraction. The positive effect of filler on thermal properties is related to wood flour acted as nucleating agent, and decrease the thermal properties at higher filler content levels is probably due to the stop the growth of crystals and the formation of amorphous. Besides, the adding of compatibilizer to the composites boosted the thermal stability and fractional crystallinity of samples. The scanning electron microscopy (SEM) micrographs demonstrate a better adhesion between the HDPE and wood flour due to the presence of the coupling agent.