Study on the ageing effect of alumina/epoxy composites modified by atmospheric plasma jet

• Published in: Polymer composites 2021-10, Vol.42 (10), p.5388-5399
• Main Authors: Kang, Yuchan, Yan, Jiyuan, Peng, Chengkai, Song, Yanze, Bian, Bo, Lü, Tianshu, Wan, Zijian, Xie, Qing
• Format: Article
• Language: English
• Subjects: aging effect; alumina/epoxy resin; Aluminum oxide; Argon plasma; Chemical bonds; Chemical reactions; Composite materials; Direct current; Electrical properties; Epoxy resins; flashover voltage; fluorination; Hydrophobicity; Insulators; Molecular chains; Oxidation; Plasma etching; plasma jet; Plasma jets; Polymer matrix composites; Surface energy; Surface properties; Surface roughness
• ISSN: 0272-8397; 1548-0569
• DOI: 10.1002/pc.26231

Alumina/epoxy resin (Al2O3/EP) composite material is widely used in the manufacture of insulators. However, the operation environment of long‐term high‐voltage direct current will destroy Al2O3/EP surface insulating performance. In this article, Al2O3/EP was modified by atmospheric pressure Ar and Ar/CF4 plasma jet, and its aging effect was studied by investigating the physicochemical characteristics and the electrical performances of the sample 0 ~ 100 days after modification. The experimental results show that after plasma treatment the surface roughness of the material increases; the O/C ratio on the surface of the material increases after Ar treatment, and the F element is grafted on the surface after Ar/CF4 treatment. These changes lead to the increase of surface energy and hydrophilicity, and the improvement of electrical performance. The surface properties change within 100 days owing to the oxidation reactions and the variability of recombination chemical bonds and molecular chains after high‐energy plasma treatment. The surface O/C ratio of the materials treated by Ar plasma is obviously reduced, the hydrophobicity is restored to some extent, and the electrical properties are also obviously weakened. In comparison, the properties of Ar/CF4 plasma‐modified materials do not change significantly. Ar and Ar/CF4 plasma jet are used to achieve the surface modification of Al2O3/EP sample. Combined with the characterization test results of the sample surface after placing for different times, the aging law and mechanism of plasma jet modified Al2O3/EP composite insulation material are studied.