ABSTRACT The present study investigated the effect of heat treatment on the relative amount of cellulose in untreated and nanosilver-impregnated poplar wood (Populus alba). The impacts on physical and mechanical properties were further studied. Specimens were heated at 145°C and 165°C in hot air medium. In order to enhance heat transfer to the inner parts of specimens, separate sets of specimens were first impregnated with nanosilver suspension in a pressure vessel. Differential scanning calorimetry (DSC) analyses showed that due to high thermal resistance of cellulose, the cellulose relative volume percent increased along with the increase in thermal temperature and the consequent degradation of other wood polymers (hemicellulose and lignin). High correlation was found between the cellulose relative volume percent versus different physical and mechanical properties. Impregnation with nanosilver increased thermal conductivity in the specimens resulting in an enhanced thermal degradation of hemicellulose and lignin, translated into an increased cellulose relative volume.

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.