Rheological properties, morphology, mechanical properties, electrical resistivity and EMI SE of cyclic butylene terephthalate/graphite/carbon black composites

Abstract

According to traits of cyclic butylene terephthalate (CBT) oligomer polymerizing into poly(butylene terephthalate) (PBT), the composites with high electromagnetic interference shielding effectiveness (EMI SE) were obtained based on CBT oligomer, graphite (GR) and carbon black (CB). The effects of GR and CB on rheological properties, morphology, mechanical properties, and electrical resistivity and EMI SE of PBT composites have been investigated using rheological rheometer, scanning electron microscope (SEM), material mechanical testing machine and electromagnetic shielding measuring instrument, respectively. The synergistic action of GR and CB was observed, which made PBT/GR/CB composites exhibit good mechanical properties, low electrical resistivity, and high vicat softening temperature (VST). Also, the incorporation of CB into PBT/GR composites improved largely EMI SE of composites, and the optimal EMI SE was determined to be ~ 60 dB over the frequency range of 30–3,000 MHz.