Influence of spherical-shaped carbon nanoparticles on the mechanical properties of a foamed sugarcane bagasse/polypropylene composite

Abstract The mechanical properties of a foamed sugarcane bagasse/polypropylene composite enhanced with spherical-shaped carbon nanoparticles (SCNs) were evaluated. SCNs were produced as sustainable and environmentally compatible nanomaterial by applying the chemical vapor deposition process (CVD) via plant and fruit wastes. Accordingly, the variables in this study were sugarcane bagasse (Saccharum officinarum) at two weight percentages (40 and 55 %), azodicarbonamide at four levels (0, 2, 4, and 6 %), and SCNs at four levels (0, 0.25, 0.5 and 1 %); the extrusion method was used in the composite preparation. The results showed that a composite of 55 % sugarcane bagasse raised the density of the nanocomposites to 0.85 g/cm3. However, increasing the foaming agent without SCNs reduced the density of the sugarcane bagasse/PP nanocomposites to 0.7 g/cm3 or by 23 %. These results demonstrate a significant reduction in the flexural strength and modulus and the tensile strength and modulus but improved the impact strength up to 29 J/m. Moreover, it was found that adding SCNs to the polymeric matrix enhanced all mechanical strengths of the foamed sugarcane bagasse/PP nanocomposites. At 1 % SCNs, the flexural strength and modulus, tensile strength and modulus, and impact strength were estimated to be 30 MPa, 2330 MPa, 14 MPa, 1210 MPa, and 30 J/m, respectively. Additionally, scanning electron microscopy also showed that the foaming agent with SCNs improved the microcellular structure of the composites due to a lower cell (bubble) size and higher cell density. It also showed that sugarcane bagasse was better dispersed in the polymer if SCNs were present. Moreover, the dynamic mechanical thermal analysis (DMTA), conducted at a frequency of 1 Hz and in a temperature range of -45 to 90 °C, demonstrated that SCNs improved the value of E′ and Tanδ, which in turn increased the energy absorption, thereby enhancing the impact strength of the composite. In summary, the addition of SCNs improved the bonding between sugarcane bagasse and PP; thus, considerably increasing all the mechanical properties of the foamed nanocomposite, particularly the impact strength.