Kim, Young Nam Kim, Minah Yoon, Somi Kim, Yebom Choi, Yong Seok Lee, Seung Jun Wie, Jeong Jae Yoon, Ho Gyu Jung, Yong Chae 2025-05-22T05:30:20Z 2025-05-22T05:30:20Z 2025-05-21 2025-07 1022-1352 https://pubs.kist.re.kr/handle/201004/152452 In this study, magnesium oxide (MgO) is introduced as an inorganic oxide filler to utilize polypropylene (PP) as an insulating material, and silane (SiO2) coating is applied to the surface of the nanoparticles to simultaneously improve the insulating properties and mechanical properties in a high-voltage direct current (HVDC) environment. First, MgO particles with an average particle diameter of approximate to 200-250 nm are surface-modified by silane treatment (MgO@SiO2) and compounded with PP matrix by biaxial melt compounding process. XPS and FT-IR analysis confirmed the effective silane coating on the surface of MgO particles, while STEM-EDX and XRM analysis visually demonstrated that the coated MgO@SiO2 is uniformly dispersed inside the PP. In terms of mechanical properties, such as tensile strength, bending strength, and strain at break, the PP/MgO@SiO2 insulation composites show superior results compared to neat PP and PP/MgO insulation composites, which are attributed to the increased interfacial affinity and improved filler dispersion due to the silane coating. In addition, the PP/MgO@SiO2 sample exhibits the highest value for direct current breakdown dielectric strength (DCBD), confirming that it can realize stable insulation performance in a high field. English John Wiley & Sons Ltd. Enhancement of High-Voltage DC Insulation Performance and Mechanical Properties in Polypropylene Nanocomposites with Silane-Coated MgO Article 10.1002/macp.202500071 1 Macromolecular Chemistry and Physics, v.226, no.14 Macromolecular Chemistry and Physics 226 14 Y scie scopus 001488361100001 Polymer Science Polymer Science Article HVDC CABLES DENSITY BLENDS HVDC MgO polypropylene silane coated DCBD