Document Type : Original research
Authors
Department of Materials Science and Engineering, Ferdowsi University of Mashhad, Mashhad, Iran
Abstract
As a novel class of lightweight conductive material, segregated polymer composites are widely regarded as their unique architecture enables the formation of electrical networks at exceptionally low filler loadings. In such configuration, the conductive phase is preferentially localized at the polymer microgranule boundaries, forming continuous channels for electron transport. This promotes superior performance, particularly in electromagnetic interference shielding. The influence of initial polyethylene particle size on electrical conductivity and electromagnetic interference shielding performance of polyethylene/carbon black segregated structured composites was studied in the present research. Composite samples were fabricated using polymer particles with varying size distributions (100–150, 150–250, 250–500, and mixed <500 μm). Characterization Results demonstrated that increase in initial polymer particle size enhances electrical conductivity; as an illustration, conductivity improved from 94.74 S/m at 105-150 μm to 163.31 S/m at 250-500 μm. In terms of shielding behavior, absorption ratio of 69-76%, confirms a dominant absorptive contribution in segregated structure regardless of initial particle size. The mixed-particle sample (<500 μm) exhibited the best overall performance, combining a high conductivity of 158.40 S/m with the highest total and absorption shielding effectiveness of 11.07 and 7.70 dB, respectively. The incorporation of finer particles not only improved interfacial adhesion among larger polymer particles, but also increased the number of “cages” that trap incident waves and prolong multiple scattering pathways.
Keywords
- Segregated structure composites
- polyethylene
- carbon black
- shielding effectiveness
- electrical conductivity
Main Subjects
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