Production of thermoplastic polyurethane composites containing carbon fiber/Fe3O4 hybrid filling material and investigation of electromagnetic shielding properties

With the rapid development of modern technology, the widespread use of electronic devices has become an integral part of our lives. These devices may emit electromagnetic waves during their operation, affecting the performance of other electronic devices around them and causing interference. This can cause major problems, especially in sensitive electronic equipment and critical applications. The need for effective electromagnetic shielding materials is increasing in order to reduce these negative effects of electromagnetic interference (EMI) and protect devices. EMI shielding materials generally consist of metals, polymers and composite materials. Metals are commonly used for EMI shielding due to their high conductivity; However, their high density, low corrosion resistance and limited flexibility may be disadvantageous in some applications. Polymers are preferred for their lightness and flexibility; However, in their natural state, their capacity to shield electromagnetic waves is low. For this reason, shielding properties are improved by adding conductive and magnetic filling materials into polymer matrices. Thermoplastic polyurethane (TPU) is a polymer material widely used in many industrial applications due to its superior properties such as flexibility, mechanical strength and chemical resistance. These advantages of TPU make it a potential material for EMI shielding applications. Carbon fiber is a filling material known for its high strength, lightness and excellent electrical conductivity. The addition of carbon fibers to the TPU matrix can significantly improve the mechanical and electrical properties of the composite material. However, adding carbon fiber alone may not be sufficient for EMI shielding effectiveness. At this point, the addition of Fe3O4 (iron oxide) filler material with magnetic properties increases the shielding efficiency by increasing the absorption of electromagnetic waves. In this thesis study; Polyurethane composites containing different ratios of carbon fiber/Fe3O4 filler material (1, 3, 5 and 7% by volume) that are light, flexible, cheap and can operate in a wide band range have been produced and their properties such as microstructure, dielectric, permeability, permittivity, conductivity and the EMI shielding of these properties have been produced. Its effects on performance were investigated.