Synthesis and microwave absorbing characteristics of flake‐like polypyrrole filled composites in X‐band

Polypyrrole (PPy)/montmorillonite (MMT) nanocompounds were prepared by in situ chemical oxidative polymerization of pyrrole in the presence of MMT. The results indicate PPy is intercalated into MMT interlayers and the morphology of obtained PPy in nanocompounds is changed to flake‐like rather than granular particles as pristine PPy. The resultant PPy/MMT nanocompounds and pristine PPy were used as microwave absorbing filler separately to prepare microwave absorbing PPy/MMT and PPy epoxy composites. The results indicate PPy/MMT epoxy composites exhibit much better microwave absorbing properties than those filled by pristine PPy. The maximum reflection loss of 20 wt% PPy/MMT filled composite is −32.63 dB at 10.55 GHz with a matching thickness of 2.8 mm, and the effective absorption bandwidth with the reflection loss below −10 dB is from 8.6 GHz to 12.4 GHz, which almost covers the whole X‐band. We postulated that the morphology change of PPy in PPy/MMT and its better dispersion may be responsible for the enhancement of microwave absorption. POLYM. COMPOS., 37:532–538, 2016. © 2014 Society of Plastics Engineers