No abstract

Polypropylene/wood flour composites with different nanoclay and maleic anhydride grafted polypropylene (PP-g-MA) contents were fabricated by melt compounding and then by injection molding. The mechanical properties, such as flexural modulus, tensile modulus, elongation at break, and impact strength, were evaluated. Results indicated that the flexural modulus, tensile modulus, and elongation at break increases with increase of nanoclay up to 3 phc at the same concentration of PP-g-MA, and then decreases. However, the impact strength of the composites decreases with increased nanoclay loading. Also, the effect of compatibilzer was positive in terms of enhancing the mechanical properties of the composites. The morphology of the nanocomposites has been examined by using X-ray diffraction and transmission electron microscopy. Morphological findings revealed that intercalation form, the sample with 3 phc concentration of clay, which implies the formation of the intercalation morphology and better dispersion than 6 phc, and the d-spacing of clay layers in the composite were improved in the presence of compatibilizer.

In this study, the effect of nanoclay on the physical and mechanical properties of nanocomposites was investigated. Composites based on polypropylene, reed fiber, coupling agent (maleated polypropylene, MAPP) and nanoclay were made by melt compounding and then injection molding. The mass ratio of reed fiber to polypropylene was controlled at 60/40 for all blends. The concentration was varied and set to 0, 2 and 4 per hundred compounds (phc) for nanoclay and 0 and 2 phc for MAPP. Results indicated that the tensile modulus and strength of PP/reed flour composites significantly increased with nanoclay loading. However, the impact strength and water uptake of the composites decreased by addition of nanoclay. Finally, the mechanical and physical analyses showed that the biggest improvement of these properties can be achieved for the nanoclay loading at 4 phc. The morphology of the nanocomposites has been examined by using X-ray diffraction. The morphological findings revealed that intercalation from the sample with 4 phc concentration of clay, which implies the formation of intercalation morphology and better dispersion, and the d-spacing of clay layers were improved in the composite in the presence of

In this study, the effect of layered nanoparticles on physical, mechanical, fire, and dynamic mechanical properties of polypropylene (PP)/hemp fiber was investigated. Composites based on PP, hemp fiber, nanoclay, and maleic anhydride-grafted PPs were made by melt compounding and then injection molding. Results revealed that the tensile modulus, tensile strength, and elongation at break of composites increased with an increase of nanoparticles loading up to 3% and then decreased. However, the impact strength decreased with the increase in nanoclay loading. Also, significant reduction in water absorption and swelling thickness has been shown with increasing nanoparticles loading. The dynamic mechanical behavior and fire properties of composites were improved by the addition of nanolayered silicates. X-ray diffraction (XRD) tests clarify that the nanoparticles in the hemp fiber/PP samples are not exfoliated, and the dispersion is in need of improvement. Finally, this project has shown that the PP/hemp fiber composites treated with layered nanoparticles will be desirable as building materials due to their improved dimensional and fire stability and strength properties.

The nanocomposites of high density polyethylene (HDPE)/bagasse flour (BF) with different contents of the organomodified montmorillonite (OMMT) were produced by melt blending process. The thermal stability and combustion behavior of nanocomposites were characterized by thermogravimetric analysis (TGA), differential scanning calorimetry, and cone calorimeter tests. The results of TGA data of the nanocomposites indicated that the OMMT greatly enhanced the thermal stability, and char residues of the HDPE/BF blends gradually increased with increasing the OMMT content. The activation energy was determined to describe the energy consumption of the initiation of the thermal degradation process. The composites produced with the 6 phc OMMT had the highest activation energy values among the evaluated composites (106 kJ/mol), whereas composites without nanoclay exhibited the lowest one. Furthermore, as the OMMT was incorporated into the nanocomposites, the melting temperature (T m ), crystallization temperature (T c ) melting enthalpy (DH m ) and crystallinity (X c ) of HDPE/BF blends increased. The findings showed that the OMMT effectively boosted the flame retardancy of nanocomposites due to the formation of the carbonaceous silicate char shields delayed time to ignition and the combustion process was remarkably hindered.