Journal of Physical Science, Vol. 32(3), 31–44, 2021 © Penerbit Universiti Sains Malaysia, 2021. This work is licensed under the terms of the Creative Commons Attribution (CC BY) (http://creativecommons.org/licenses/by/4.0/). Conductive Polymer Composites Made from Polypropylene and Recycled Graphite Scrap Dylan Jia Yee Tong, 1 Seong Chun Koay, 1* Ming Yeng Chan, 2 Kim Yeow Tshai, 3 Thai Kiat Ong, 2 and Yose Fachmi Buys 4 1 School of Computer Science and Engineering, Faculty of Innovation and Technology, Taylor’s University Lakeside Campus, No. 1, Jalan Taylor’s, 47500 Subang Jaya, Selangor, Malaysia 2 Faculty of Engineering and Technology, Tunku Abdul Rahman University College, Jalan Genting Kelang, Setapak, 53300 Kuala Lumpur, Malaysia 3 Faculty of Engineering, The University of Nottingham, Jalan Broga, 43500 Semenyih, Selangor, Malaysia 4 Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia * Corresponding author: seongchun.koay@taylors.edu.my Published online: 25 November 2021 To cite this article: Tong, D. J. Y. et al. (2021). Conductive polymer composites made from polypropylene and recycled graphite scrap. J. Phys. Sci., 32(3), 31–44. https://doi.org/10.21315/jps2021.32.3.3 To link to this article: https://doi.org/10.21315/jps2021.32.3.3 ABSTRACT: Electric Discharge Machining (EDM) process uses electrodes made from graphite that wear out over time and are turned into scrap. In this research, EDM electrode scraps were recycled and turned into graphite powder (rGP). This rGP was used as a conductive fller to produce conductive polymer composite (CPC) material by combining it with polypropylene (PP) resin via melt compounding and compression moulding processes. The percolation threshold of this composite material changed when 30 wt% of rGP was added, whereby the insulative material changed became antistatic. The composite was able to achieve surface resistivity as low as 10 5 ohm/sq. However, the addition of higher rGP content deteriorated the tensile properties of composite, whereby the tensile strength of composite signifcantly decreased as compared to neat PP. The results also showed that the tensile modulus of this composite became higher, and the material became more brittle as compared to neat PP. However, the PP/rGP composite with 50 wt% fller content reduced the tensile modulus due to plasticising efect caused by the agglomeration of rGP. The addition of high fller content on PP/rGP composite also caused an increase in processing torque. This was due to the restriction of rGP particles to the melt fow of molten PP. The morphological analysis found that the PP/rGP composites with higher amounts of fller content were highly agglomerated and formed conductivity