Experimental investigation of mechanical properties of injected polymeric nanocomposites containing multi-walled carbon nanotubes according to design of experiments

In present study, the tensile strength and hardness of polymeric nanocomposites containing multi-walled carbon nanotubes (MWCNT) are investigated. For this purpose, polyamide-6 and MWCNTs in various weight percentages are melt compounded using a twin-screw extruder. To investigate the influence of MWCNTs and injection molding processing parameters on tensile strength and hardness, the samples in various MWCNT contents including 0, 0.5, 1 and 1.5 weight percentages and under different processing parameters including holding pressure and injection temperature, are injection molded according to Taguchi design of experiments. According to the results of signal to noise (S/N) ratio, the weight percentage of MWCNT is the most effective parameter on the tensile strength and hardness of samples. Also, the results indicate that by adding 1 wt% of MWCNT, the tensile strength of samples increased almost 31% and by addition of 1.5 wt% MWCNT, the hardness increased about 15%. Furthermore The results of analysis of variance (ANOVA) indicates that wt% of MWCNT with 68% and 76% contribution percentage on tensile strength and hardness of samples, are the most effective processing parameters, respectively.