Morphology and electrical properties of polypropylene/polyamide 6/glass fiber composites with low carbon black loading

Abstract

Abstract The objective of this study is to investigate the electrically conductive properties and percolation thresholds of carbon black (CB)-filled polypropylene (PP)/glass fiber (GF), PP/polyamide 6 (PA6), and PP/PA6/GF composites. Compared to CB-filled PP/GF and PP/PA6 composites, PP/PA6/GF/CB composites exhibited a reduction of the percolation threshold. Under the same CB loading, the surface resistivity of PP/PA6/GF/CB composites was much lower, indicating a better conductivity. According to the morphology images characterized by transmission electron microscopy, CB was preferentially located in the PA6 phase due to the good interaction between CB and PA6 and the lower viscosity of PA6. The addition of GF formed a PA6-coated GF structure. This structure with a relatively long diameter can effectively assist the construction of conductive paths. Meanwhile, GF also played a volume-occupying role and improved the effective concentration of the conductive component in the system. The influences of GF and PA6 mass fraction on the surface resistivity of PP/PA6/GF/CB composites were also explored, respectively. It was found that appropriate amounts of GF and PA6 could effectively increase the electrical conductivity, providing guidance for fabricating an antistatic or conductive material with high comprehensive performance.