Effect of the Cross-Linking Process on the Electrical Resistivity and Shape-Memory Behavior of Cross-Linked Carbon Black Filled Ethylene-Octene Copolymer

The electrical resistance of carbon black (CB) filled ethylene-octene copolymer (EOC) was monitored during the compression molding step by means of conductivity sensors. It increases strongly during the cross-linking process due to the de-agglomeration of CB aggregates. After completion of cross-linking reaction CB aggregates reagglomerate causing a decay of resistance. The electrically stimulated shape-memory (SM) behavior was found to be strongly dependent on the extent of electrical resistivity and the rigidity of CB network, which is formed during compounding and subsequent cross-linking process. The effect of amount of peroxide and cross-linking conditions like time and temperature on resistivity and the related SM behavior was characterized. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 120: 2138-2145, 2011