Study of the conductivity of Nylon 6/ABS blends.

In this research project the study was conducted on conductivity of acrylonitrile butadiene styrene (ABS)/Nylon 6 blend with carbon black as conductive filler. Three different blends of ABS/carbon black, Nylon 6/carbon black and ABS/Nylon 6/carbon black with various compositions were prepared by mixing together by using a single screw extruder. Each compound was reblended to achieve homogeneous mixture and the effect of processing was studied.Conductivity of the low resistance of blends were obtained by measuring sheet resistance using four-point probe as according to ASTM F 1529. The sheet resistance could only be detected for ABS/carbon black 20 wt % and above, and ABS/Nylon 6 with 80:20 ratio with 10 wt % of carbon black. Whereas, for Nylon 6/carbon black blends and the others high resistance of blends, their resistances were measured by Teraohmeter according to ASTM D 257 method. Percolation threshold (critical volume fraction) of the blends was studied to find actual conductive filler contents to avoid deterioration of mechanical properties. In this case, tensile tests were conducted according to ASTM D 638 to establish their mechanical properties. Meanwhile, scanning electron microscopy (SEM) was used to study the morphology of blended polymers, interface of polymer/carbon black and aggregation phenomenon between carbon black and polymers. The correlation between conductivity, mechanical properties and morphological characterisation of all the blends was studied.The results show that, the addition of carbon black up to 10%, increases conductivity and tensile strength of ABS/carbon black and Nylon 6/carbon black blends. Conductivity continues to increase with further addition of carbon black, but at the expense of tensile strength reduction due to the effect of brittle nature of carbon black.By adding ABS in ABS/Nylon 6/carbon black blends, conductivity increases, whereas tensile strength decreases. However, tensile strength of ABS/Nylon 6/carbon black blends were too low to compare with individual polymer blended with carbon black, due to immiscibility between ABS and Nylon 6. Reblending the compound for the third time increases conductivity and mechanical properties due to increase in homogeneity and uniform distribution of carbon black dispersion. Both ABS and conductive carbon black absorb moisture that can effect the properties of compound. Drying of the compound will remove moisture which will result in improvements in conductivity and tensile strength