Dielectric and thermal properties of thermoplastic elastomer gels in the presence of nanographite

Abstract

Abstract:In this work, the effect of different nanographite such as expandable graphite (EG) and exfoliated graphite nanoplatelets (xGnP) on the electrical and thermal properties of nanocomposite thermoplastic elastomer gels prepared from a poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) imbibed with an EBcompatible paraffin oil was investigated. The electrical properties have been studied as a function of variation of nanoparticles in the frequency range of 5 2 to 10 7 Hz. For all the nanoparticles studied, the dielectric constant increases as the volume content of the nanoparticles in the TPE gels increases. The increase in dielectric constant was fairly smooth with no clear dielectric singularity in the concentration range studied. However, the percolation threshold in the dielectric spectra was clearly seen. The incorporation of a small quantity of nanographite improved the thermal stability of the swollen midblock of TPEGS, since the particles dispersed in this region, thereby increasing the distinct region of oil degradation temperature but no improvement on SEBS matrix. The results showed that size, shape and agglomeration of the particles with high amount of oil in SEBS system played a role in the dielectric properties and thermal stability.

Properties of styrene-ethylene-butylene styrene block copolymer/exfoliated graphite nanoplatelets nanocomposites

“…This result is similar to that of thin films reported by Motomatsu et al 46 The same effect of thick films and gel forms for block copolymers has been also observed by TEM. 42,47,48 As can be seen from the figures, when increasing the styrene content in SEBS matrix, the xGnPs particles were dispersed homogeneously and less agglomeration. This phenomenon was also observed in the SEM images.…”

“…Among these works are the incorporation of intercalated clay in to SEBS in the presence of a compatibilizer in SEBS grafted maleic anhydride [37][38][39][40] and the effect of processing and silane coupling agent in copolymer elastomer with graphite. [41][42][43][44][45] In this work, the nanocomposite polymer was prepared by embedding xGnPs into styrene-ethylene-butylene-styrene block copolymer by simple melt compounding approach. Their effects on the morphological properties, thermal behavior and mechanical properties were reported and discussed.…”

“…Among these works are the incorporation of intercalated clay in to SEBS in the presence of a compatibilizer in SEBS grafted maleic anhydride 37-40 and the effect of processing and silane coupling agent in copolymer elastomer with graphite. 41-45…”