The effect of nanoclay contents on the physical and mechanical properties of bagasse flour/ reprocessed high density polyethylene (rHDPE)/ nanoclay composites was investigated. The bagasse flour content was constant at 50%, the maleic anhydride content was constant at 3%, and the nanoclay (Cloisite 30B) content was set at three different levels: 0%, 2%, and 4%. The materials were mixed in a co-rotating twin-screw extruder; afterwards, the specimens were fabricated using an injection molding method. The water absorption and mechanical properties, such as flexural and tensile strength, flexural and tensile modulus, and notched impact strength, were measured. The nanoclay dispersion was examined by X-ray diffraction. The results indicated that tensile and flexural modulus increased with an increase in nanoclay content. Also By increasing the nanoclay content at 2 wt.%, the tensile and flexural strengths of the composite were increased. However, the addition of 4 wt.% nanoclay resulted in reductions of these properties. Water absorption decreased with increasing nanoclay content. The structural examination of the bagasse polymer composite with X-ray diffraction showed that the nanoclay was distributed as an intercalated structure in the polymer matrix, and the d-spacing of layers decreased with increasing nanoclay content. Scanning electron microscopy (SEM) showed that 2% nanoclay samples with lower and more uniform pores compared at 4% nanoclay samples, respectively.

The 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.

The effects of the amount of nanographene on physical, mechanical, and thermal properties and morphology of the wood-plastic composites were investigated. This wood-plastic was made using recycled high density polyethylene (HDPE), nanographene, and wood flour. Four weight levels, 0, 0.5, 1.5, or 2.5 wt.% of nanographene, were combined with 70% polymeric matrix and 30% lignocellulosic material with an internal mixer. The results showed that by increasing the amount of nanographene up to 0.5% by weight, the flexural strength, flexural modulus, and notched impact strength of the composite increased. After adding 2.5 wt.% nanographene, these properties were reduced. By increasing the amount of nanographene, both the amount of residual ash and the thermal stability increased. Study of the images from scanning electron microscope (SEM) showed that the samples containing 0.5% of nanographene had less pores and were smoother than other samples.

The flammability behavior of wood/plastic nanocomposites made from recycled polystyrene, wood flour, and nanoclay were investigated in this study. The wood flour was mixed, using the two weight ratios of 40 wt.% and 60 wt.% with recycled polystyrene, and nanoclay was added at 0 wt.% and 5 wt.%. A coupling agent was also added at up to 3 wt.% of the composite. The results showed that the oxygen index increased when higher contents of wood flour were added. Furthermore, it was found that the samples required more oxygen for ignition when the percentage of wood flour was increased. Similarly, it was found that the samples required a greater amount of oxygen for ignition with increasing nanoclay content. Therefore, the flammability of the sample decreased because the time to ignition took longer in the absence of sufficient oxygenation. X-ray analysis of the nanocomposites revealed that the morphological structure involved intercalation.

The effects of acetylation of wood flour with vinylacetate and the content of Maleic Anhydride Polypropylene (MAPP) coupling agent before compounding were evaluated relative to water absorption and thickness swelling. Hot water was used to extract materials of sawdust fir flour before acetylation. Fir flour was successfully acetylated using vinylacetate (VA) in the presence of potassium carbonate. The modification was confirmed by the weight percent gain (18.8%) and Fourier transform Infrared (FTIR) spectroscopy. The acetylated or control wood flour was mixed with MAPP coupling agent (0, 3, & 6 wt%) at 60 rpm and 160 °C, followed by extrusion. The wood plastic composite (WPC) was made by hot pressing at 200 °C and 25 MPa for 5 min. Specimens were exposed to white-rot decay for 16 weeks. In addition to the weight loss due to fungal treatment, water absorption, thickness swelling, and contact angle of the acetylated and decayed samples was investigated. Increasing the percentage of MAPP was found to decrease the percentage of weight loss, water absorption, and thickness swelling in all of the samples. In contrast, increasing the MAPP percentage increased the contact angle in all samples. The SEM micrographs revealed that the bonding between fibers and polymeric material was improved and strengthened by MAPP addition.