Sains Malaysiana 50(7)(2021): 2025-2034

http://doi.org/10.17576/jsm-2021-5007-17

 

Effect of Multi-Sized Graphite Filler on the Mechanical Properties and Electrical Conductivity

(Kesan Pengisi Grafit Berbilang Saiz pada Sifat Mekanikal dan Kekonduksian Elektrik)

 

NABILAH AFIQAH MOHD RADZUAN1,2*, ABU BAKAR SULONG1,2 & ISWANDI3

 

1Precision Research Group, Department of Mechanical and Manufacturing, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor Darul Ehsan, Malaysia

 

2Fuel Cell Plate Material and Manufacture Group, Fuel Cell Institute, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor Darul Ehsan, Malaysia

 

3Department of Mechanical Engineering, Institut Teknologi Medan, Medan, Indonesia

 

Diserahkan: 7 Ogos 2020/Diterima: 30 November 2020

 

ABSTRACT

This research successfully fabricated conductive polymer composites (CPCs) prepared using multiple sizes of graphite filler (40, 100, 150, and 200 µm) that provided excellent network formation within the fillers and polypropylene matrix which further improved both electrical conductivity and flexural strength. An important discussion on the fabrication technique, including compression moulding and injection moulding was conducted, to manufacture CPC materials with a thickness less than 3 mm. The findings of this study suggested that fabricating CPCs using the compression moulding technique with a graphite composition of 75 wt. % exhibited better network connectivity as the electrical conductivity increased to 15 Scm-1. Also, compared to the three sizes of graphite filler (40/100/200 µm) it resulted in 13 Scm-1, with two sizes (40/200 µm) reporting better electrical conductivity at 15 Scm-1. This demonstrated that the addition of multiple sizes was not necessarily due to agglomeration occurring. The resultant graphite composites of 40/200 µm possessed a more stable structure having a thin composite layer (2.5 mm) which promoted better electrical conductivity suitable for bipolar plate used in proton exchange membrane fuel cells.

 

Keywords: Carbon; composites; electrical conductivity; fuel cells; mechanical properties

 

ABSTRAK

Kajian ini berjaya menghasilkan konduktif polimer komposit (KPK) dengan menggunakan beberapa jenis saiz pengisi grafit (40, 100, 150 dan 200 µm) yang berupaya menghasilkan jaringan elektrik yang cemerlang antara pengisi dan matrik polimer sekaligus meningkatkan nilai keberaliran elektrik dan kekuatan tegangan. Perbincangan penting ditekankan pada kaedah pembuatan termasuk penggunaan kaedah pembentukan mampatan dan pengacuan suntikan dalam pembikinan bahan KPK berketebalan kurang 3 mm. Penemuan kajian ini menunjukkan pembuatan bahan KPK menggunakan kaedah pembentukan mampatan pada komposisi grafit sebanyak 75 % bt. mampu menghasilkan jaringan keberaliran elektrik yang baik dengan nilai keberaliran elektrik direkodkan sebanyak 15 Scm-1. Perbandingan ke atas tiga saiz pengisi grafit berbeza iaitu (40/100/200 µm) memperoleh nilai keberaliran elektrik sebanyak 13 Scm-1 manakala penggunaan dua saiz pengisi grafit memperoleh nilai sebanyak 15 Scm-1 iaitu jauh lebih baik. Keadaan ini menunjukkan bahawa pertambahan saiz berbeza tidak semestinya meningkatkan nilai keberaliran elektrik kesan daripada pergumpalan yang lebih mudah berlaku. Kajian menunjukkan komposit grafit dengan saiz 40/200 µm mempunyai struktur yang lebih stabil serta nilai keberaliran elektrik lebih tinggi dengan ketebalan 2.5 mm bersesuaian dengan aplikasinya sebagai plat dwikutub dalam sel fuel membran penukar proton.

 

Kata kunci: Karbon; keberaliran elektrik; komposit; sel fuel; sifat mekanikal