PREPARATION AND RESISTIVITY-TEMPERATURE DEPENDENCE OF LSCO CARBON BLACK/POLYETHYLENE COMPOSITES/

Carbon black (CB) filled high density polyethylene (HDPE) composites w ere prepared by thermal roll-milling technique, and the positive tempe rature coefficient (PTC) characteristics of the resistance of the comp osites were studied. The ternary LSCO-CB-HDPE composites using LSCO (L a0.5Sr0.5CoO3) powder as the third phase filler were prepared, and the effect of LSCO powder on the PTC characteristics of CB-HDPE composite s were investigated. It was found that LSCO powder strengthens the PTC effect, and decrease the negative temperature coefficient (NTC) effec t of the composites, and consequently LSCO is a good candidate for PTC composite filler. It was discovered that the composites consist of th e network structures which are caused by the filling of LSCO powder. T he improvement of PTC effect of the composites is attributed to the ne twork structure, the formation mechanism of which is discussed from hy drophilic nature points of view.