AbstractThe effect of the size of bagasse and nanoclay on mechanical properties and morphology of bagasse flour/recycled polyethylene nanocomposite was studied. The content of bagasse flour was considered to be constant at 40%, with the size of the remaining flour on sieves of mesh 40, 70, and 100, and the accompanying nanoclay content being 0, 2, and 4 wt%, respectively. It was found that tensile strength, flexural strength, and tensile and flexural modulus were increased by decreasing the size of the particles to mesh 70. Notched impact strength was also increased by reduction of the flour dimensions. Increasing the nanoclay content up to 2 wt% led to enhanced tensile and flexural strengths as well as tensile and flexural moduli of the composite material. These properties were hurt by the addition of 4 wt% nanoclay. On the other hand, increasing the nanoclay content up to 4 wt% is expected to decrease notched impact strength of the composites. X-ray diffraction (XRD) data indicated that the order of intercalation was higher at 2 wt% nanoclay in comparison with the samples containing 4 wt% nanoclay, and the d-spacing of layers decreased with increasing of nanoclay particles content.