Study on Electric Tree of Nano-SiO2Polypropylene Composite Insulation Material

In this paper, PP (Polypropylene), SEBS (Styrene Block Copolymer) and SiO₂nanocomposites have been studied to provide basic performance information for the engineering application of polypropylene cable. Three kinds of nanocomposites (PP / SiO₂/ SEBS, PP / SEBS / SiO₂and SiO₂/ SEBS / PP) and PP / SEBS materials were prepared by adding media in different order. The electrical branch aging experiment was carried out with PP, PP/SEBS and nanocomposites. The dispersion of the nanometer SiO₂particles in composite polypropylene was observed by Scanning Electron Microscope (SEM). The results show that the nanometer SiO₂of PP / SiO₂/ SEBS is mainly dispersed in PP phase and the interface of PP / SEBS. Nanometer SiO₂of PP / SEBS / SiO₂is uniformly dispersed in PP and SEBS phases. Nanometer SiO₂of SEBS / SiO₂/ PP mainly exists in SEBS phase and the interface of PP/SEBS. The initial growth voltage and growth process image information of each composite were obtained by the electric tree observation system. The results showed that PP / SiO₂/ SEBS had the best inhibition on electric dendrites among the three kinds of nanocomposites, and the second was PP / SEBS / SiO₂, and the worst among them was SEBS / SiO₂/ PP. The results showed that SEBS promoted the initiation and growth of electric branch in PP, and SiO₂ inhibited the growth of PP. Nanometer SiO₂ particles dispersed in the medium lead to different electrical dendritic growth ability of nanocomposites. Nanometer SiO₂dispersed in PP phase inhibits the electrical dendritic growth best.