Polymer Composite with Enhanced Thermal Conductivity and Insulation Properties through Aligned Al₂O₃ Fiber

Thermoplastic polyolefins, such as polyethylene (PE), are traditionally one of the most widely used polymer classes with applications in the electric industry, and their nanocomposites have caught the interest of researchers. The linear filler is shown to be beneficial in decreasing the charge injection and hindering the formation of charge packs. So, we demonstrate a novel composite with excellent properties. The low-density polyethylene (LDPE) composite with aligned aluminum oxide (Al₂O₃) fiber has been prepared in electric field conditions. The direction of the Al₂O₃ fiber was parallel to the thickness direction of the LDPE composite. The breakdown strength of the Al₂O₃/LDPE composite with 0.2% aligned Al₂O₃ fiber was 498 kV/mm, which is higher than other fillers induced. The aligned Al₂O₃ fiber has effect on preventing accumulation of space charge and reducing the amount of free electron in the material. In addition, the thermal conductivity of the LDPE composite (0.22 W/m·K) was increased to 0.85 W/m·K when doped with 0.5 wt% aligned Al₂O₃ fiber. The present structure provides a new possibility for mass new nanocomposites with excellent microstructures and remarkable functionality.