EMI shielding response of polypyrrole-MWCNT/polyurethane composites

•TPU-PCNT composites show much higher EMI shielding (−48 dB) compared to TPU-PPy composites (−18 dB).•Just 2 wt. % MWCNTs with respect to total weight gives sufficient synergistic effect and improvement in EMI shielding response.•Tensile strength increases up to 10 wt. % loading of PCNT. Composites based on thermoplastic polyurethane [TPU] as matrix and polypyrrole/MWCNT (PCNT) as filler were prepared which inherit conducting, dielectric and magnetic attributes of polypyrrole/MWCNT [PCNT] filler. Polypyrrole/MWCNT was synthesized by in-situ polymerization of pyrrole monomer by chemical oxidative method in presence of MWCNT and fabrication of composites was carried out using solution blending method. The effect of polypyrrole /MWCNT content on electrical and microwave shielding efficiency of TPU was investigated to evaluate their potential as an effective EMI shield. These composites show absorption dominated total shielding effectiveness (SET) up to −46 dB in frequency range of 8.2–12.4 GHz (X-band) suggesting their utility for microwave absorbers. The EMI shielding result was also compared with polyurethane composites using neat polypyrrole (PPy) as filler. Polyurethane composites prepared using PCNT as filler showed much higher shielding efficiency (−46 dB using 40 wt. % PCNT filler) as compared to polyurethane composites having only PPy as filler (−18 dB using 40 wt. % PPy filler).