Synthesis and investigation of microwave characteristics of polypyrrole nanostructures prepared via self-reactive flower-like MnO2 template

• In the present work, 3D PPy morphology effect on the microwave absorbing properties is investigated for the first time.
• PPy microspheres consisted of interweaved polypyrrole nanostructures were successfully synthesized, using assembled δ-MnO2 flower-like.
• In the preparation method, the MnO2 flower like served as both oxidative polymerization initiator and physical template.
• The PPy nanostructures are totally inherited from the MnO2 templates.
• PPy morphologies significant factor which will effect on the dielectric and microwave properties of PPy nanostructures.

One of the substantial topics in business field and also for military purposes is radar absorbing technology. Intrinsic conducting polymers (ICP) such as polyaniline and polypyrrole which have advantages such as high conductivity, high flexibility, ease synthesis routes, high stability and good mechanical properties, have aroused intense of many researches for Radar absorbing materials (RAMs) applications. Also, these polymers can help to design the ideal RAMs. In this paper, the dielectric and microwave absorbing properties of 3D polypyrrole (PPy) microspheres consist of interweaved PPy nanostructures/paraffin composite have been reported in the frequency range of 2–18 GHz, for the first time. As well as, a one-step route for the chemical synthesis of PPy via a reactive template of MnO2 was successfully used. For this purpose, the reactive template of MnO2 was prepared by a facile hydrothermal method. The synthesized MnO2 was used as initiator for polymerization reaction. The XRD pattern and the EDX spectra confirmed that the MnO2 template consumed as the initiator. The SEM images indicated that the δ-MnO2 sample is composed of uniform flower-like microsphere nanostructures and the PPy nanostructures are totally inherited from the MnO2 templates.