Abstract: The electrical conductivity of PVC/CB foam made from carbon black, PVC and EPDM was studied. The bubble structure and resistivity-temperature characteristic were observed. Influences of carbon black content, crosslinker, foamer on conductive properties of PVC/CB foaming conductive composites were investigated. The obtained foam has a rather good bubble structure and mainly performs NTC effect during heating process. For the composites with high content of CB, PTC effect after a long time NTC effect was found. The conductive mechanism was explained and the proper filler contents of crosslinker and foamer were confirmed to make the composite have not only good foam performance but also NTC characteristic.

Key words: PVC, foam, CB, conductive composite, negative temperature coefficient effect