Effect of Carbon Black Mass Fraction on the Conductivity of Carbon Black/Polypropylene Composite

Carbon black/polypropylene composite was prepared by melt blending,and the effect of carbon black mass fraction on the conductivity of carbon black/polypropylene composite were studied.Result showed that the composite exhibited evident percolation threshold effect,with percolation value of 8%.The percolation threshold was decreased to 5% and the volume resistivity was lowered three magnitude after coupling treatment of carbon black.The occurrence of percolation threshold was in good agreement with thermodynamic theory.As the increase of carbon black content,saturation and excess were appeared in the interface of composite system.SEM observation indicated that carbon black particles formed a continuous network structure when the excess reach a value,resulting in a great decrease of the conductive percolation threshold.