Experimental Study on Oriented Mechanical, Rheological and Optical of a Multi-Walled Carbon Nanotube/Polymethyl Methacrylate Anisotropic Nanocomposite

In order to achieve better mechanical properties of the nanocomposites containing carbon nanotubes, the carbon nanotubes should be oriented in a specific direction in the polymer matrix. This produces nanocomposites with anisotropic properties. Experimental study on the effect of injection direction and carbon nanotubes orientation on the mechanical properties of a multi-walled carbon nanotube (MWCNT)/polymethyl methacrylate (PMMA) anisotropic nanocomposite is the main aim of this article. Therefore, variable input factors including MWCNT concentration (0, 0.5, 1 and 1.5 wt%) and its in-flow and perpendicular directions were studied. First, nanocomposites were produced by co-rotating twin-screw extrusion. After that the nanocomposite sheets were fabricated by injection molding and test samples were cut into standard dimensions by laser cutting. The parameters including elastic module, yield strength, elongation, impact strength and hardness were studied. In addition, the effect of MWCNT on the melt flow index and optical properties was studied. Morphology of nanocomposites was carried out by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Increasing the elastic modulus by about 51%, tensile strength by 19% and elongation by 27% with addition of 1.5 %wt MWCNTs were also found. The results also illustrated that the elastic modulus improved by 10% and tensile strength by 13 % in the direction perpendicular to the flow direction. Yet more elongation was observed in in-flow direction. A little drop in hardness, a slight increase in impact strength and a decrease in luster and transparency by increases in MWCNTs loading were other noticeable results. A reduction in melt flow impact from 11 to 6.3 g/10min was another remarkable finding.