Electrical and thermal studies of the distribution of carbon black in a polyester matrix in the presence of aluminum oxide

Abstract

The distribution of a filler in a polymeric matrix is one of the most important factors affecting the physical properties of the final product. For this reason, the main objective of this study was to introduce aluminum oxide (Al 2 O 3 ), acting as a dispersing agent, to reduce the filler-filler interaction and enhance the filler-polymer interaction. To achieve this aim, the electrical behavior of a styrenated polyester resin filled with different amounts of high-abrasion furnace black in the presence of 5% Al 2 O 3 was studied in the vicinity of the percolation threshold to evaluate the effect of the addition of Al 2 O 3 in an attempt to reduce the filler-filler interaction through the polyester matrix. At a certain concentration of carbon black, an abrupt increase was noticed through electrical conductivity, permittivity, and dielectric loss investigations. With this increase, the tendency of conductive chain formation increased through the aggregation of a carbon black particle network. The addition of 5% Al 2 O 3 improved the filler distribution by lowering the aggregate size and consequently enhanced the formation of the network. From the Arrhenius temperature dependence of the electrical conductivity, the activation energy and pre-exponential factor were obtained, and they confirmed the validity of the compensation law for the semiconducting composite systems. The composites were also analyzed by thermogravimetric analysis. Al 2 O 3 improved the thermal stability of the composites in comparison with that of a sample free of Al 2 O 3 .

Some Studies on HAF Reinforced Epoxy Composites

“…Similar results were obtained by Mansour et al [25]. Mg(OH) 2 improves the thermal stability of carbon black composite samples in terms of delay of the onset degradation temperature from 270 to 3508C and from 2758C to 3758C for 20 and 30 wt% HAF, respectively ( Figure 9).…”

Modulation of the Reactivity of a WO3/Al Energetic Material with Graphitized Carbon Black as Additive

“…Thermal conductivity is then a key parameter of the nanothermite. Carbon blacks are widely used as enhancers of the electrical and thermal conductivities of polymers or electrodes [35]. Because the influence of carbon on conductivity is related to a percolation effect between the additive particles, the addition of 5 wt% carbon is not expected to significantly modify the REACTIVITY OF NANO-WO 3 /Al WITH CARBON ADDITIVES thermal conductivity of the nanothermite.…”

Dielectric relaxation analysis of biopolymer poly(3‐hydroxybutyrate)

“…The dielectric dispersion of the aliphatic polyester as a function of frequency in the vicinity of T g relaxation can be described by Havriliak‐Negami (HN) phenomenological equation 34–37. Then, the complex dielectric permittivity ε* is given by: where Δε = ε s − ε ∞ , is the dielectric strength, ε s and ε ∞ are the relaxed and unrelaxed dielectric constants, respectively.…”