Electromagnetic interference shielding effectiveness of carbon black and carbon fibre filled EVA and NR based composites

• Published in: Composites. Part A, Applied science and manufacturing Applied science and manufacturing, 2000-01, Vol.31 (10), p.1069-1081
• Main Authors: Das, N.C, Khastgir, D, Chaki, T.K, Chakraborty, A
• Format: Article
• Language: English
• Subjects: A. Carbon fibre; Applied sciences; Composites; Electromagnetic interference; Exact sciences and technology; Forms of application and semi-finished materials; Polymer industry, paints, wood; Technology of polymers
• ISSN: 1359-835X; 1878-5840
• DOI: 10.1016/S1359-835X(00)00064-6

Electromagnetic interference (EMI) shielding characteristics of natural rubber and ethylene vinyl acetate filled with conductive carbon black (Vulcan XC-72) and short carbon fibre (SCF) have been studied. The measurements of shielding effectiveness (SE) were carried out in two different frequency ranges 100–2000 MHz and 8–12 GHz (X-band range). The return loss and loss due to absorption were also measured as a function of frequency in the X-band range and microwave region. It is observed that the SE of the composites is frequency dependent, especially at higher frequency range, and it increases with the increasing frequency. The SE also increases with the increase in filler loading. The SCF filled composites show higher SE compared to that of conductive carbon black. The correlation between SE and conductivity of the various composites is also discussed. The results indicate that the composites having higher fibre loading (≥20 phr) can be used for the purpose of EMI shielding, as well as for some microwave applications.