Experimental investigation of properties of polymeric nanocomposite foams containing multi-walled carbon nanotubes using Taguchi method

In the present study, the properties of polymeric nanocomposite foams investigated in variant multi-walled carbon nanotubes (MWCNTs) content and under various processing parameters. For this purpose, polyamide 6 (PA6) selected as matrix and melt compounded with MWCNT in variant weight percentages (i.e. 0, 0.5, 1 and 1.5%) using a twin-screw extruder. Then, the prepared nanocomposites were foamed using Azodicarbonamide as blowing agent by injection molding machine based on Design of Experiments (DOE) using Taguchi method according to L16 orthogonal array. Influence of weight percentage of MWCNTs and injection molding processing parameters including holding pressure and holding pressure time (all in four levels) investigated on mechanical and structural properties of nanocomposite foam samples. Specific tensile strength investigated as mechanical property and for investigation of structural properties of nanocomposite foam samples, SEM test has been done that the results of this test showed that a well microcellular structure achieved. According to the results of signal to noise ratio (S/N) weight percentage of MWCNTs is the most effective parameter on specific tensile strength and structural properties of nanocomposite foam samples. The results demonstrated that by adding 1 wt% of MWCNTs, specific tensile strength of samples increased about 147%. Also, the results indicated that by addition of MWCNTs, cell density increased and mean cell size decreased that means providing optimal conditions for foaming.