Microwave-absorbing performance and mechanical properties of poly(vinyl chloride)/acrylonitrile-butadiene rubber thermoplastic elastomers filled with multiwalled carbon nanotubes and silicon carbide

摘要

Poly(vinyl chloride) (PVC)/acrylonitrile-butadiene rubber (NBR) were mixed with multiwalled carbon nanotubes (MWCNTs) and silicon carbide (SiC) to prepare microwave-absorbing composites. The complex permittivity, direct-current (dc) conductivity, microwave-absorbing performance, morphology, and mechanical properties of the composites were studied. The real and imaginary parts of the permittivity of the composites increased with increasing MWCNT content. The premixing of the MWCNTs with PVC was more beneficial to the dispersion of MWCNTs; this led to a higher dc conductivity and permittivity and better microwave-absorbing performance than the premixing of MWCNTs with NBR for the PVC/NBR/MWCNT composites. The PVC/NBR/MWCNT composites had a minimum reflection loss (RL_(min)) of -49.5 dB at the optimum thickness of 1.96 mm. The efficient microwave absorption of the PVC/NBR/MWCNT composites was due to a high dielectric loss and moderate permittivity. The incorporation of SiC into the PVC/NBR/MWCNT composites increased the real and imaginary parts of permittivity of the composites. When the SiC content was 70 phr, RL_(min) decreased to -34.9 dB at a thickness of 3 mm.