Water absorption behaviour in polyethylene boron nitride nanocomposites

Abstract

Abstract-Polymer nanocomposites, when prepared and treated carefully, have the potential to offer many advantages over the current materials used in high voltage applications. Four materials have been prepared containing 2 wt%, 5 wt%, and 10 wt% of hexagonal boron nitride nanofiller, including an unfilled material based on a polyethylene blend. The water absorption behavior was studied by measuring the change in mass in the different samples, at different humidity conditions, and using dielectric spectroscopy. Dielectric spectroscopy was used to measure both the real relative permittivity and the dielectric losses. Under dry and ambient conditions, the materials behave similarly and exhibit insignificant losses. Under wet conditions, the unfilled polyethylene does not seem to be affected, however, the nanocomposites exhibit some dielectric losses as expected. The wet samples were easily dried off and therefore behaved similarly to the originally dry samples with no apparent losses.

Enhanced dielectric properties of polyethylene/hexagonal boron nitride nanocomposites

“…Many studies of water uptake and accumulation at nanoparticle/polyethylene interfaces have been undertaken [32][33][34], which have demonstrated that the presence of the resulting bound water is readily seen in the dielectric spectrum and that the presence of this water has a marked detrimental influence on electrical performance. In contrast, the systems considered here interact extremely weakly with water, which implies the presence of few accessible hydroxyl groups at hBN/polyethylene interfaces [35]; this is discussed fully elsewhere [36]. Another consequence of this lies in the critical role that hydroxyl moieties play in commonly used surface functionalisation strategies [37].…”

An overview of boron nitride based polymer nanocomposites

“…[ 118 ] R. Ayoob and his coworkers also used melt pressing at 180°C to fabricate polyethylene boron nitride nanocomposites. [ 119 ] In 2017, Ş. Gözdeİrim and coworkers prepared h‐BN/Gd 2 O 3 /HDPE ternary nanocomposites by melt compounding method and they observed that the increased concentration of h‐BN and Gd 2 O 3 can reduce the neutron and gamma transmission by better neutron/gamma radiation filler interaction. [ 120 ] The fabrication of PP/BN composites using a batch kneader followed by compression molding technique was also studied.…”

The dielectric effect of xylene on an organoclay-containing composite

“…[2] It is well known that the presence of water can alter the dielectric properties of nanocomposites. For example, Ayoob et al [3] found that the permittivity increased with nanofiller content when samples were immersed in water, while Lau et al found there to be a significant difference in the dielectric response of polyethylene after immersion in water, depending on the surface treatment of the nanofiller [4]. These effects were interpreted in relation to the adsorption of dipolar water molecules at nanoparticle surfaces, whereupon, the precise dynamics were governed by local hydrogen bonding effects.…”