Segregated structure of poly (vinylidene fluoride-co-hexafluoropropylene) composites loaded with polyaniline@carbon nanotube hybrids with enhanced microwave absorbing properties

Abstract

Polyaniline@carbon nanotube (PAni@CNT) hybrid with electrical conductivity of 5.2 S/cm was successfully prepared by inverted emulsion polymerization of aniline in the presence of CNT dispersed in toluene assisted by cetyl-trimethyl ammonium bromide (CTAB). Conductive composites based on poly (vinylidene fluoride-co-hexafluoropropylene) (PVDFH) loaded with different amounts of PAni and PAni@CNT were prepared by dry-blending the powders in a ball-mill followed by hot compression molding. This procedure resulted in a segregated structure of the fillers, as indicated by scanning electron microscopy (SEM). The composite with 10 wt% of PAni@CNT (9.5: 0.5 wt%) hybrid exhibited electrical conductivity near 10−3 S/m and outstanding electromagnetic wave (EMW) attenuation. Indeed, reflection loss (RL) of − 34 dB (more than 99.9% EMW attenuation) at 11.7 GHz and effective absorption bandwidth (EAB) frequency with RL < −10 dB (more than 90% EMW attenuation) corresponding to 7.3 GHz were observed for this composition with thickness of 3 mm. A comparative analysis of measured and calculated RL was conducted. Considering the simple and cost effective preparation procedure, these composites loaded with 5 wt% and 10 wt% of the hybrid material are promising alternatives for developing efficient microwave absorbing material for both military and civil applications.