The study on the electromagnetic properties of polyurethane coated pre-oxidized fiber felt composites

Abstract

In this study, coated pre-oxidized fiber felt composites were prepared using the PU2540 polyurethane as a matrix and adopting a coating technology on the pre-oxidized fiber felt. Firstly, influences of wave-absorbing functional particles on the dielectric properties and shielding effectiveness of single-layer coated pre-oxidized fiber felt composites were analyzed and compared. Secondly, influences of the graphene content on the dielectric properties and shielding effectiveness of graphene coated pre-oxidized fiber felt composites were discussed. Results showed that values of the real and imaginary parts and loss tangent value of the dielectric constant for graphene coated pre-oxidized fiber felt composites were all larger than those of graphite coated pre-oxidized fiber felt composites, that is, the former had a stronger polarization ability, dissipation ability and attenuation ability to electromagnetic waves than the latter. However, the shielding effectiveness of the latter was larger than that of the former, that is, the shielding ability of graphite coated pre-oxidized fiber felt composites was better than that of graphene coated pre-oxidized fiber felt composites. When the graphene content was 15% of the mass of the polyurethane, the value of the imaginary part and loss tangent value of the dielectric constant for graphene coated pre-oxidized fiber felt composites were both the largest, and the dissipation ability and attenuation ability to electromagnetic waves were both the strongest.