Temperature dependent electrical conductivity and microwave absorption properties of composites based on multi-wall carbon nanotubes and phthalocyanine polymer

Abstract

Phthalocyanine (Pc) polymer composites containing multi-walled carbon nanotubes (MWCNTs) were successfully prepared via thermal annealing and their microwave absorption properties were tuned by changing the annealing temperatures from 300 to 500 °C. The effects of the introduction of MWCNTs into Pc polymer matrices and elevated annealing temperature on the electrical conductivity and the permittivity of the composites have been investigated. The results indicated that the synergistic effect of electrical conductivity and the permittivity endowed the composites with excellent microwave absorbing properties. Particularly, the reflection loss peak achieved a minimum value of −59.50 dB at 11.84 GHz when the sample with a thickness of 2.36 mm was annealed at 450 °C. The tuning of electromagnetic parameters of polymer composites by changing annealing temperature provided a simple and effective technical direction for the design of microwave attenuation materials.