The Effect of $\text{FeS}_{2} / \text{Co}$-BTC on the Thermal Conductivity and Dielectric Properties of LDPE Matrix

Enhancing the thermal conductivity of low-density polyethylene (LDPE) is crucial for improving the heat dissipation performance of electrical insulation systems. In this study, $\text{FeS}_{2}$, Co-BTC (cobalt benzene-1,3,5-tricarboxylate), and $\text{FeS}_{2} / \text{Co}^{-} B T C(F C)$ nanomaterials were prepared via the solvothermal method. These materials were incorporated into LDPE matrices at different mass fractions using the melt blending method to systematically investigate the thermal conductivity and dielectric properties of the three resulting LDPE-based composites. The results demonstrate that the introduction of nanomaterials significantly enhances the thermal conductivity of LDPE. Among them, the $\text{FeS}_{2} / \text{Co}_{0}-\text{BTC}_{2} / \text{LDPE}(\text{FC}-\text{LDPE})$ composite exhibits the most remarkable improvement: at a filler loading of $2.0 \text{wt} \%$, its thermal conductivity increases by $54.45 \%(0.295 ~\mathrm{W} /(\mathrm{m} \cdot \mathrm{K}))$ compared to pure LDPE. Dielectric property tests show that both the dielectric constant and dielectric loss of the composites increase linearly with the filler content. The FC filler, owing to its high dielectric constant carriers and interfacial polarization effects, most significantly improves the dielectric constant of the LDPE-based composites, reaching 2.48 when the filler content is 2.0 wt%. This study provides a theoretical basis for optimizing the thermal and electrical properties of LDPE-based insulating materials through nanohybrid strategies, highlighting the potential applications of the prepared composites in high-power cable insulation.