MULTI-WALLED CARBON NANOTUBES EFFECT IN POLYPROPYLENE NANOCOMPOSITES

The paper presents a study concerning thermoplastic nanocomposites having polypropylene as the matrix and different contents of carboxyl-functionalized multi-walled carbon nanotubes as the nanofiller. The materials are obtained by melt compounding the nanofiller powder and polymer pellets through the extrusion process followed by injection molding into specific-shape specimens. The materials are evaluated in terms of mechanical properties such as the tensile and flexural strengths and moduli, the thermal stability under load (the heat deflection temperature) and the thermal-behavior properties using a TG-DSC analysis. The fracture cross-section is analyzed using FTIR spectroscopy and SEM microscopy to evaluate the bulk characteristics of the materials. The results show positive effects of the nanofiller addition to the thermoplastic polymer on the mechanical strength and modulus of the materials during flexural and tensile tests, while in the case of the thermal stability under load, the nanofiller addition has a minor influence on the heat-deflection-temperature values.