Electromagnetic properties and performance of exfoliated graphite (EG) – Thermoplastic polyurethane (TPU) nanocomposites at microwaves. (19th June 2015)

• Record Type: Journal Article
• Authors: Valentini, M.; Piana, F.; Pionteck, J.; Lamastra, F.R.; Nanni, F.
• Is Part Of: Composites science and technology. Volume 114(2015)
• Page Start: 26
• Page End: 33
• Publication Date: 2015-06-19
• Subjects: Exfoliated graphite -- A. Functional composites -- A. Nano composites -- A. Polymer-matrix composites (PMCs) -- B. Electrical properties; Composite materials -- Periodicals; Composite materials; Fibrous composites; Periodicals; 620.118
• DOI: 10.1016/j.compscitech.2015.03.006
• Languages: English
• ISSNs: 0266-3538

Abstract

Abstract: Nanocomposite materials based on commercial thermoplastic polyurethane (TPU) loaded with exfoliated graphite (EG) in concentration between 0 and 20 wt.% have been prepared with EG via melt mixing and compression molding. The materials' electromagnetic properties have been measured with wave-guide technique between 8.2 and 12.3 GHz. They had shown a clear proportional dependence of complex permittivity with EG content. Above 16 wt.% permittivity becomes frequency dependent. These results are discussed in view of material microstructure by means of scanning electron microscope (SEM) observations. Samples, with 20 wt.% EG and 4 mm thick, show an average value of −20 dB of shielding effectiveness (SE), which make them suitable as shielding material for commercial application. Simulations of metal backed configuration showed that important narrowband EM absorption (>−15 dB) can be achieved at 1 mm thickness, while multilayer structures are necessary to obtain EM broadband absorption (>−10 dB between 8.5 and 12 GHz) can be achieved in 6 mm thick samples.