Enhancing electrical characteristics and electromagnetic interference shielding effectiveness in thermoplastic elastomeric polymer blends by utilizing the selective distribution of conductive black

Abstract

Abstract The selective distribution of filler within polymer blends presents a compelling advantage, notably manifesting as a reduced percolation threshold when compared to an individual polymer matrix with a random filler dispersion. In this context, a thermoplastic elastomeric (TPE) blend comprising ethylene propylene diene rubber (EPDM) and linear low-density polyethylene (LLDPE), denoted as EL, has been meticulously formulated. The incorporation of varying amounts of conductive carbon black (Vulcan XC 72; VCB) into this TPE matrix has been achieved through conventional melt blending, yielding a composite material with exceptional electromagnetic interference (EMI) shielding effectiveness of -27.80 dB at 50 phr (parts per hundred rubber). This success is credited to the creation of a linked structure resulting from a dual-step percolation process. The selective distribution of carbon black (CB) throughout the TPE mixture results in a decreased critical concentration for connectivity and enhanced electromagnetic interference (EMI) shielding performance. This advancement underscores the potential of EPDM-LLDPE-VCB (ELV) composites to safeguard against electromagnetic radiation. It paves the way for their utilization in various techno-commercial applications, where a balance of mechanical strength, thermal stability, and flexibility is crucial. Graphical Abstract

Keywords

• Polymer blends
• Conductive carbon black
• Co-continuous morphology
• Selective distribution
• Electrical conductivity
• Double percolation behavior