Electromagnetic wave absorption, EMI shielding effectiveness and electrical properties of ethylene - vinyl Acetate (EVA)/Polyaniline (PAni) blends prepared by in situ polymerization

Flexible, low cost and scalable microwave absorbing materials are very important for application in the telecommunication area and also in stealth technology for military purpose. In the present work, polyaniline doped with dodecylbenzene sulfonic acid (PAni.DBSA) was synthesized in the presence of ethylene vinyl acetate (EVA) copolymer by in situ inverted emulsion polymerization and the corresponding composites were explored as potential electromagnetic wave absorbing materials and electromagnetic interference shielding materials in the X-and Ku-band frequency range. The properties of the composites, such as rheological, electrical and dielectric properties, were investigated as a function of the composite composition. The findings reveal that the microwave absorption of EVA@PAni composites is influenced by the PAni content, with the optimal attenuation achieved by the composite with 33 vol % PAni. This composite displays superior microwave absorbing performance, with a minimum reflection loss of-39 dB (99.99 % attenuation) at 16.65 GHz. This study demonstrates the potential of EVA@PAni composites as microwave-absorbing materials, mainly in the higher frequency range (Ku band) and open new possibilities of developing flexible, low-cost, lightweight and processable materials for applications in both civil and military field.