Electrical Property of Ni Composite Based on HDPE and PMMA Having Differnt M sub(W)

• Published in: Kōbunshi ronbunshū (Tokyo) Vol. 70; no. 9; pp. 483 - 488
• Main Authors: Shimizu, Katsuya, Nakano, Hajime, Kono, Akihiko, Takahashi, Seiji, Nishiyama, Takashi, Horibe, Hideo
• Format: Journal Article
• Language: English
• Published: 09.05.2014
• Subjects: Dispersions; Electrical properties; Electrical resistivity; Melts; Nickel; Particulate composites; Polyethylenes; Polymethyl methacrylates
• DOI: 10.1295/koron.70.483
• ISSN: 0386-2186

The electrical properties of Ni particle dispersed high-density polyethylene (HDPE) or Poly(methyl methacrylate) (PMMA) composites depend both on its Ni content and the weight-average molecular weight (M sub(W)) of its base polymer. Moreover, we suspect a different conduction mechanism for polymers with a different M sub(W). As expected, the resistivity at room temperature ( rho sub(L)) decreases with increasing Ni content in HDPE/Ni and PMMA/Ni, because many conductive paths are formed with increasing Ni content. For equal Ni content in HDPE/Ni, rho sub(L) decreases, while the temperature of PTC effect increases with decreasing M sub(W). On the other hand, in PMMA/Ni composites, rho sub(L) decreased and the temperature of PTC effect increased with increasing M sub(W). This tendency is opposite in HDPE/Ni composites. This can be explained with the different distribution of Ni particles in the polymer. SEM images show that Ni particles are unevenly distributed in HDPE/Ni, while it was uniformly distributed PMMA/Ni. Therefore, we think that in HDPE/Ni the change of the degree of crystallinity of polymers with different M sub(W) influences the conductivity strongly. In amorphous PMMA/Ni, the difference in the viscosity after polymer melt strongly influences the conductivity.