Effects of carbon black(CB) particle distribution

feeding sequence and blending time on the electrical conductivity of high density polyethylene(HDPE)/ethylene-vinyl acrylate copolymer(EVA) blends filled with CB were investigated by using scanning electron microscope(SEM) and transmission electron microscope(TEM).The results reveal that CB particles distribute selectively in HDPE phase due to better flexibility of HDPE chains than that of EVA.Feeding order significantly influences the electrical conductivity of the composites by affecting the distributed status of CB particles in the two immiscible phases

i.e.HDPE phase and EVA phase.In order to gain high electrical conductivity

CB should be firstly added into EVA and then HDPE is added

or EVA and HDPE are initially blended uniformly and then CB particles are added.Blending time also has remarkable effect on the electrical conductivity of the composites.With the increase of blending time

the electrical resistivity of all the polymer composites with different feeding sequences decreases firstly and then increases.In later stage of blending

the electrical resistivity of HDPE/EVA-CB changes slightly with blending time compared with the other two blend systems.The phase morphology evolution dominates the conductivity of HDPE/CB-EVA during blending

however

distribution of CB particles dominates the conductivity of HDPE/EVA-CB.To achieve better electrical conductivity

appropriate feeding sequence and blending time should be adopted.