The Effects of Aluminum-Nitride Nano-Fillers on the Mechanical, Electrical, and Thermal Properties of High Temperature Vulcanized Silicon Rubber for High-Voltage Outdoor Insulator Applications

Abstract

AlN nanoparticles were added into commercial high-temperature-vulcanized silicon rubber composites, which were designed for high-voltage outdoor insulator applications. The composites were systematically studied with respect to their mechanical, electrical, and thermal properties. The thermal conductivity was found to increase greatly (>100%) even at low fractions of the AlN fillers. The electrical breakdown strength of the composites was not considerably affected by the AlN filler, while the dielectric constants and dielectric loss were found to be increased with AlN filler ratios. At higher doping levels above 5 wt% (~2.5 vol%), electrical tracking performance was improved. The AlN filler increased the tensile strength as well as the hardness of the composites, and decreased their flexibility. The hydrophobic properties of the composites were also studied through the measurements of temperature-dependent contact angle. It was shown that at a doping level of 1 wt%, a maximum contact angle was observed around 108°. Theoretical models were used to explain and understand the measurement results. Our results show that the AlN nanofillers are helpful in improving the overall performances of silicon rubber composite insulators.

Effect of water on the breakdown and dielectric response of polypropylene/nano-aluminium nitride composites

“…An identical result was reported, where nano-AlN from the same manufacturer was used [29]. It is worthy to mention that many inconsistent particle size distribution between observations and the data provided by suppliers has been reported for nano-AlN, including in our previous work [11,30,31], and we suggested that this could be related to the hydrolytic instability of AlN powders. Li et al [28] reported that the morphology and particle size distribution of the AlN microparticles are significantly changed after exposure to moist air (80 RH%) for 400 h and can have a dehydration weight loss up to 20% after being heated to 500°C.…”

Preparation and Performance of Silicone Rubber Composites Modified by Polyurethane

“…SIR used for outdoor insulation materials also needs to have high resistivity, thermal conductivity and electrical strength. Adding metal oxides, nitrides and reduced graphene oxide can increase the insulation's performance [10][11][12][13]. In order to improve the electrical properties, the erosion and wear resistance of silicone rubber in the field of high-voltage insulation, SIR composites were prepared by filling them with aluminum hydroxide (ATH), irregular silica (IS), spherical silica (SS) and silicon dioxide (SiO 2 ) by mechanical blending [14][15][16].…”