Polyethylene-based composites with increased thermal conductivity and thermal stability – the effect of magnesium oxide modified with zinc oxide

Effect of zinc oxide-modified magnesium oxide (ZnO/MgO) and its preparation methods (two- or single-step calcination using zinc acetylacetonate or zinc acetate, respectively) on the thermal conductivity and thermal stability of PE was investigated. SEM, XRD, and XPS studies confirmed effective deposition of ZnO on MgO surface, uniform particle distribution, preservation of MgO crystalline structure, and formation of a stable coating. The synergistic effect of both oxides significantly improved both the thermal conductivity and thermal stability of PE, with better results obtained using ZnO-modified MgO manufactured in the two-step process. The highest thermal conductivity and thermal stability were observed for MgO containing 2 wt% ZnO. At higher ZnO content, agglomerates were formed, which resulted in deterioration of thermal properties.