Correlation between mechanical dissipation and improved X-band electromagnetic shielding capabilities of amine functionalized graphene/thermoplastic polyurethane composites

Abstract

Graphene-based polymer nanocomposites have demonstrated significant promise to create commercially viable electromagnetic interference (EMI) shielding to protect the next-generation of electronic materials from radiative pollution. In the present study, we carry out a systematic analysis of the dynamic mechanical, dielectric, electrical and X-band shielding properties of thermoplastic polyurethane (TPU) elastomer filled with amine functionalized graphene obtained by the rapid thermal expansion of graphite oxide. By preparation of nanocomposites based on modified and unmodified graphene using solution mixing and hot compression moulding, we demonstrate that the modification with 2-aminoethyl methacrylate enhances the EMI shielding from 14 to 25 dB. We also show by fracture analysis, crosssectional transmission electron microscopy and dynamic mechanical analysis that the modification significantly strengthens the interfacial interactions between TPU and the functionalized graphene at the same filler loading. We find that the dominant shielding mechanism is through absorption and discuss the correlation between the viscoelastic mechanical loss tangent and the more effective dissipation of absorbed EM radiation which might account for the discrepancy between the theoretically predicted and experimentally observed EMI SE.

A journey of thermoplastic elastomer nanocomposites for electromagnetic shielding applications: from bench to transitional research

“…The fabricated film composite with a graphene loading of 20% exhibited a qualified bandwidth of shielding effectiveness (SE) Z 20 dB as wide as B49.1 GHz in a broadband frequency range of 5.4-59.6 GHz. Esfahani et al 148 prepared nanocomposites based on TPU and both unmodified and surface functionalized graphene sheets via a solution mixing process. The influence of graphene modification on the electrical and dielectric properties were studied for both groups of composites loaded with various levels of filler.…”

From Waste to Functional Materials: A Multifunctional Electromagnetic Interference Shielding Composite from Waste Rock Wool

“…With the rapid development of electronic devices and communication technology, electromagnetic interference (EMI) pollution not only threatens human health but also affects the function of nearby electronic instruments. , A variety of materials with EMI shielding properties have been extensively investigated to eliminate unwanted electromagnetic radiations, − such as those polymer composites composed of conductive carbon nanotubes or graphene. − Among them, the EMI shielding materials fabricated from the wastes are particularly attractive − because not only the amount of wastes is reduced but also highly valuable products are obtained. However, most reports have focused on the improvement of a single performance of EMI shielding materials and it does not meet the requirements of complex environments, which require EMI shielding materials possessing more functions.…”

Thermoplastic polyurethane–graphene nanoplatelets microcellular foams for electromagnetic interference shielding

“…The final performance of the TPU can be easily tuned by controlling the ratio of soft and hard segments; due to their versatility, TPU elastomers have traditionally been used in automotive, electronics and construction 10 . The addition of GRM to TPU for development of nanocomposites with improved electrical properties 11,12 , sensing 13,14 and EMI shielding applications 15 has been already reported.…”