(200q) Magnetic Polymer Nanocomposites for Electromagnetic Interference Shielding

Due to the development of electrical devices, the electromagnetic wave radiation is a potential threat to human being’s health.¹ Polymer nanocomposites show great potential for electromagnetic interference (EMI) shielding application. In this project, epoxy nanocomposites reinforced with polypyrrole functionalized nano-magnetitie (Fe₃O₄-PPy) showed significantly enhanced electromagnetic wave absorption performance and flame retardancy. The Fe₃O₄-PPy were prepared by a surface initiated polymerization method. The epoxy/(30.0wt%)Fe₃O₄-PPy nanocomposites possessed a minimum reflection loss (RL) value of -35.7 dB, much lower than either epoxy/(7.5wt%)PPy nanocomposites with a minimum RL value of -11.0 dB or epoxy/(30.0wt%)Fe₃O₄ with a minimum RL value of -17.8 dB at the same thickness (1.7 mm). Meanwhile, the bandwidth of epoxy/(30.0wt%)Fe₃O₄-PPy nanocomposites for RL<-10 dB and RL<-20 dB (which means about the 90% and 99% attenuation of the incident electromagnetic wave) was 4.0 and 0.8 GHz, respectively. The increased interface area, eddy current loss and anisotropic energy were essentially important to acquire higher reflection loss and broader absorption bandwidth for epoxy/(30.0wt%)Fe₃O₄-PPy nanocomposites. Moreover, the significantly reduced flammability was observed in the epoxy/(30.0 wt%)Fe₃O₄-PPy nanocomposites compared with pure epoxy. The total heat release of epoxy/(30.0 wt%)Fe₃O₄-PPy decreased from 25.5 kJ/g of pure epoxy to just 12.3 kJ/g. The mechanical property, magnetic property, electrical conductivity and particle dispersion quality of the epoxy nanocomposites were reported as well. These new nanocomposites with enhanced electromagnetic wave absorption property and flame retardancy possess great potential to be deployed for safer electromagnetic wave absorber in electronic industry to satisfy stringent industrial standards.²

Reference:

1. K. Zhang, H.-O. Yu, Y.-D. Shi, Y.-F. Chen, J.-B. Zeng, J. Guo, B. Wang, Z. Guo and M. Wang, Journal of Materials Chemistry C, 2017, 5, 2807-2817.

2. J. Guo, H. Song, H. Liu, X. Liu, C. Luo, X. Zhang, J. Kong, Z. Guo, Y. Ren, T. Ding, M. A. Khan and D. P. Young, Journal of Materials Chemistry C, 2017, DOI: 10.1039/C7TC01502J.

Acknowledgements：

This project is financially supported by the American Chemical Society Petroleum Research Fund (ACS PRF# 53930-ND6).