Microstructure and properties of poly(butylene terephthalate)/poly(ethylene terephthalate) composites based on carbon nanotubes/graphene nanoplatelets hybrid filler systems

This work describes the preparation of poly(butylene terephthalate) (PBT)/poly(ethylene terephthalate) (PET) composites using carbon nanotubes (CNTs)/graphene nanoplatelets (GNPs) hybrid fillers by melt blending process. The effects of CNTs/GNPs hybrid fillers on the thermal conductivity, electrical conductivity, electromagnetic interference shielding effectiveness (EMI SE) and mechanical properties of composites with varying CNTs/GNPs weight ratios were investigated. Scanning electron microscopy showed that the CNTs/GNPs hybrid fillers had better dispersion in PBT/PET matrix, they could effectively cooperate to build filler network structure. The excellent synergistic effects of hybrid fillers could significantly improve the mechanical properties and thermal conductivity. When adding 2 phr CNTs and 8 phr GNPs simultaneously, the thermal conductivity reached 0.84 W m(-1) K-1 and Young's modulus was 1.2-fold compared with PBT/PET blends. In addition, all hybrid composites with higher CNTs/GNPs weight ratios showed better electrical conductivity and EMI SE. The measurement of EMI SE and study of shielding mechanism indicated that absorption loss was the main mechanism for the attenuation of incident electromagnetic waves in hybrid composites over X-band frequency.

Automated summary

This study investigated the effects of CNTs/GNPs hybrid fillers on the properties of PBT/PET composites prepared by melt blending process. The hybrid fillers were found to enhance mechanical properties and thermal conductivity, as well as improve electrical conductivity and EMI SE. Absorption loss was identified as the main mechanism for the attenuation of incident electromagnetic waves in the hybrid composites.