Hybrid Composites Based on Thermoplastic Polyurethane With a Mixture of Carbon Nanotubes and Carbon Black Modified With Polypyrrole for Electromagnetic Shielding

Frontiers in Materials

Guilherme M. O. Barra¹  Mayara C. Bertolini¹  Sílvia D. A. S. Ramoa¹  Bluma G. Soares²  Claudia Merlini³  Alessandro Pegoretti⁴ 

[1] Departamento de Engenharia Mecânica, Universidade Federal de Santa Catarina, Florianópolis, Brazil;Departamento de Engenharia Metalúrgica e de Materiais, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil;Departamento de Engenharia, Universidade Federal de Santa Catarina, Blumenau, Brazil;Department of Industrial Engineering and INSTM Research Unit, University of Trento, Trento, Italy;

关键词: carbon black;    polypyrrole;    carbon nanotubes;    thermoplastic polyurethane;    electromagnetic shielding;   

DOI  :  10.3389/fmats.2020.00174

来源: DOAJ

【 摘 要 】

Hybrid conducting composites comprising thermoplastic polyurethane (TPU) and mixtures of carbon black modified with polypyrrole (CB-PPy) and carbon nanotubes (CNT) were prepared by melt mixing process. The electrical conductivity, rheological properties and electromagnetic shielding effectiveness (EMI SE) of TPU/CB-PPy and TPU/CNT composites were also investigated those results observed for TPU/CB-PPy/CNT hybrid composites. TPU/CNT composites show a very sharp insulator-conductor transition and the electrical percolation threshold was about 1 wt% of CNT, which was lower than that found for TPU/CB-PPy (7 wt%). Moreover, EMI SE values of TPU/CNT composites were higher than those for TPU/CB-PPy due to the denser CNT conductive pathway into TPU matrix. In order to achieve the highest electrical conductivity and EMI SE values, mixtures of CB-PPy/CNT were added in the composites in different mass fractions. In fact, the electrical conductivity values increased by combining CB-PPy and CNT, resulting in hybrid composites of TPU/CB-PPy/CNT with higher EMI SE values when compared to TPU/CB-PPy composites. The present study demonstrates the potential use of hybrid polymer composites containing 5 or 8 wt% of CB-PPy/CNT at specific CB-PPy/CNT ratios with good processabilty and EMI SE values as high as −20 dB indicating the potential use of these materials for electromagnetic shielding application in the X-band frequency region.

【 授权许可】

Unknown