In this study, the effects of carbon black (CB) content and anodic oxidation treatment with AgNO3 on positive temperature coefficient (PTC) behavior of CB/HDPE nanocomposites were investigated. Also, the addition of elastomer as a toughing agent was studied. The 20~50 wt% of CB, 0~5 wtt% of elastomer, and 1 wt% of AgNO3-filled HDPE nanocomposites were prepared using the internal mixer in 60 rpm at 160˚C and the compression-molded at 180˚C for 10 min. As a result, the room temperature resistivity and PTC intensity of the composites were dependent, to a large extent, on the content of CB, addition of elastomer, and surface chemical properties that were controlled in the relative arrangements of the carbon black aggregates in a polymeric matrix. Moreover, the composites with relatively low room temperature resistivity and suitable PTC intensity could be achieved by treatment of AgNO3. Consequently, it was noted that PTC effect was due to the deagglomeration or the breakage of the conductive networks caused by thermal expansion or crystalline melting of the polymeric matrix.

• Soo-Jin Park(Advanced Materials Division, Korea Research Institute of Chemical Technology)
• Min-Kang Seo(Advanced Materials Division, Korea Research Institute of Chemical Technology)
• Jae-Rock Lee(Advanced Materials Division, Korea Research Institute of Chemical Technology)