Hybridization Effects of Carbon Fillers on the Electrical, Thermal, and Mechanical Performances of <scp>PVDF</scp> ‐Based Composites

ABSTRACT This study explores the synergistic effects of hybrid graphite (GR) fillers combined with carbon fibers (CFs) and carbon black (CB) on the performance of PVDF‐based conductive polymer composites (CPCs). Composites were formulated with a fixed GR loading of 60 wt% using optimized mixtures of GR particle sizes: G1 (5.9 μm), G2 (17.8 μm), and G3 (561 μm). To investigate the synergistic effect of hybrid carbon additives on CPCs performance, up to 10 wt% of GR was replaced with CB, CF, or a CB/CF mixture. The G2/G3 (3:1) system showed optimal binary GR performance, with a decomposition temperature of 425°C, through‐plane/in‐plane resistivities of 0.66/0.58 Ω cm, and flexural/compressive strengths of 41.5/17.1 MPa. Replacing 7.5 wt% of G2/G3 with CF improved thermal stability (440°C) and lowered through‐plane/in‐plane resistivities (0.33/0.17 Ω cm), although it slightly decreased flexural/compressive strengths (37.2/13.0 MPa). Replacing 5 wt% with CB reduced thermal stability (400°C) but further lowered both resistivities (0.23/0.16 Ω cm), along with reducing strengths (19.5/5.2 MPa). A ternary mixture (CF/CB: 2.5/7.5 wt%) yielded the best electrical performance (0.097/0.087 Ω cm), modest strengths (16.1/3.6 MPa), and a decomposition temperature of 402°C. These results highlight how tuning filler size and composition enhances the multifunctional performance of PVDF‐based CPCs.