Significantly high electromagnetic shielding effectiveness in polypyrrole synthesized by eco‐friendly and cost‐effective technique
Rekha Agrawal, Jyoti Shah, Govind Gupta, Ritu Srivastava, Chhemendra Sharma, R. K. Kotnala
Abstract
Abstract A facile and eco‐friendly synthesis of polypyrrole from monomer pyrrole using nominal amount of ferric chloride hexahydrate (FeCl 3 .6H 2 O) oxidant in aqueous solution by chemically oxidative polymerization method has been reported. The use of aqueous solvent and ferric chloride hexahydrate salt in polypyrrole synthesis have an eco‐friendly route favorable for the production of polypyrrole in large quantities. The synthesized polypyrrole samples exhibit good electrical conductivity (2 S/cm) and yield of 80% for reaction time of 8 hr at 5°C. Quality and properties of polypyrrole samples have been thoroughly investigated with varying reaction time and temperature while other synthesis parameters like molar ratio of oxidant to monomer, oxidant concentration, and solvent were kept constant. X‐ray diffraction analysis of polypyrrole with a shorter reaction time shows the presence of iron oxide (Fe 2 O 3 ) peaks. The complete reaction may not occur at shorter reaction times due to which residual ferric ions converted into Fe 2 O 3 . X‐ray photoelectron spectroscopy measurement of polypyrrole also confirms the formation of Fe 2 O 3 . Appropriate selection of reaction time and temperature produced pure phase polypyrrole with high yield and good conductivity. Synthesized polypyrrole by our eco‐friendly and cost‐effective technique exhibits prominent electromagnetic shielding effectiveness value of 30 dB in the X‐band (8–12 GHz).