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

Abstract

The influence of water immersion and silane treatment on the AC breakdown and the complex dielectric response of polypropylene/nano-aluminium nitride (PP/nano-AlN) composites has been investigated. The as-received filler was examined to have a nanoscale particle distribution with a hexagonal shape and slight hydrolysation. Grafting the aluminium nitride with an octyl silane reduces the weight increase in samples filled with 10 wt% of aluminium nitride during water immersion by 3, from 0.29 to 0.09%. The results suggest that the AC breakdown strength and complex permittivity of ''wet'' composite samples are related to the silane treatment of the nanofiller. The AC breakdown strength of octyl silane-treated samples after 9 days of water immersion shows comparable results to the dry samples, while a reduction can be seen on non-treated samples. Although silane-treated samples still show an increased dielectric loss at low frequency after water immersion, a significant reduction in low-frequency dispersion of real and imaginary permittivity can be seen when compared to the non-treated composites. This indicates that significant gains can be obtained for PP/nano-AlN composites by suitable silane treatments.

Highly Thermal Conductive and Electrical Insulating Epoxy Composites with a Three-Dimensional Filler Network by Sintering Silver Nanowires on Aluminum Nitride Surface

“…The crystalline structures of the filler and 3D network are shown in Figure 3 . The XRD patterns of the raw AlN and AgNW depicted in Figure 3 a contain regular peaks, which are consistent with the data reported in previous studies [ 36 , 37 ]. After the growth of AgNWs on the AlN surface, the obtained AA XRD patterns include both the AlN and AgNW peaks, suggesting that the deposited AgNWs retained their crystalline structure.…”

An overview of boron nitride based polymer nanocomposites

“…The polymer composites using inorganic nanomaterials as fillers have attracted much attention owing to their distinctive properties and various potential applications in the construction, automotive, aerospace and electronics industries. [5][6][7][8] In order to enhance the functionality and performance of a polymer nanocomposites, thermally conductive inorganic fillers like silicon carbide, [9] aluminum nitride, [10] aluminum oxide, [11] boron nitride, [12] etc., and metal oxide fillers such as SiO 2 and TiO 2 have been explored. [13,14] Noble metals such as gold and silver can also be used, however with limited applications due its expensive nature.…”

Aging assessment of insulating materials through broadband dielectric measurements: the appropriate frequency choice

“…This leads to e.g., a constant increase of the property for Material #1 (Figure 3.a) However, it may be difficult to single out the degradation contribution from these measurements, particularly if fillers are present in the compound. As an example, ATH fillers, as hydroscopic species, can easily bond with environmental moisture which is known to bring to a raise of the material conductivity [10]. This could be considered the reason for the constant value of conductivity for Material #2 (Figure 3.b) for aging times <500h.…”