• DOI:10.1002/APP.29702
• Corpus ID: 55710332

Electrical, dielectric, and electromagnetic shielding properties of polypropylene‐graphite composites

@article{Panwar2010ElectricalDA,
  title={Electrical, dielectric, and electromagnetic shielding properties of polypropylene‐graphite composites},
  author={Varij Panwar and Jong-Oh Park and Sukho Park and Sanjeev Kumar and Ram Mohan Mehra},
  journal={Journal of Applied Polymer Science},
  year={2010},
  volume={115},
  pages={1306-1314}
}

• Varij Panwar, Jong-Oh Park, +2 authors R. M. Mehra
• Published 5 February 2010
• Materials Science
• Journal of Applied Polymer Science

The conducting polymer composite material is desired to have a high dielectric constant and high dissi- pation factor in low and high frequency ranges, so that it can be used in charge storing devices, decoupling capaci- tors, and electromagnetic interference (EMI) shielding appli- cations. Currently, on-going research is trying to enhance the dielectric constant of ceramic powder-polymer, metal powder-polymer, and nanotube-polymer composites in the low frequency region. In this article, we present the dielec- tric properties of polypropylene (PP)-graphite (Gr) compo- sites in low and radio frequency ranges. Furthermore, the EMI shielding properties of these composites are examined in the radio frequency range. The PP-Gr composites were prepared by mixing and the hot compression mold tech- nique. The electrical conductivity and dielectric constant of PP-Gr composites with graphite volume fraction follow the power law model of percolation theory. The percola- tion threshold of the composites is estimated to be 0.0257 (� 5wt % of Gr). The current of PP-Gr composites as a func- tion of voltage shows a nearly ohmic behavior above the percolation threshold. Shore-D hardness of the composites is decreased with the addition of conducting filler. The PP- Gr composites exhibit a high dielectric constant and high dissipation factor with the addition of graphite in low fre- quency and radio frequency regions, so they can be used in the proposed applications. V C 2009 Wiley Periodicals, Inc. J Appl Polym Sci 115: 1306-1314, 2010