Hyperelastic behavior and dynamic mechanical relaxation in carbon black‐polymer composites

Abstract

Tensile and thermo‐mechanical properties of nano‐composites fabricated by mechanically mixing semi‐crystalline ethylene‐co‐butyl acrylate (EBA) and carbon black (CB) nanoparticles are investigated. Stress–strain curves performed on samples over a broad range of CB content evidence the hyperelastic behavior of the EBA matrix. Neo‐Hookean and Mooney‐Rivlin models are used to fit the observed linear and nonlinear mechanical behaviors, respectively. The thermo‐mechanical curves highlight two relaxation phenomena depending on the CB content. Correspondingly, the EBA/CB interface properties are analyzed by correlating the volume fraction of the constrained polymer to the relaxation behavior of the viscoelastic linear regime. POLYM. COMPOS., 40:3005–3011, 2019. © 2018 Society of Plastics Engineers

Nano‐indentation for probing mechanical properties of nanocomposites based on ethylene butyl acrylate copolymer and carbon black

“…The low wear resistance of highly filled composite samples may be linked to their low toughness as it is deduced from the tensile properties performed on the current composite materials. Moreover, the increase of CB concentration leads to a large increase of the stiffness and to a reduction of the toughness . It is to be noticed that the lower deviation of H / E values for highly loaded composite samples indicates a good dispersion of CB throughout the polymer matrix confirming the same conclusions reported in our previous studies by using dielectric and mechanical analyses.…”

“…Note that no correlation between the values of C l and the CB volume fraction is found for studied range of CB vol %. On the basis on the reported values obtained for both rubber and rigid polymers, we believe to observe of a decrease of C l with increasing the CB volume fraction because the CB particles increase the stiffness of the matrix . It might be prudent to take a definitive conclusion especially with few studies reported on the matter.…”

“…We will now pay attention to the plausible correlations between the indentation results from submicron to micro scales and the tensile properties of the same series of composites investigated in former studies at room temperature …”

“…The butyl acrylate monomer (4.3 mol %) contains butylester side groups providing a polar character and a relative low crystallinity 20 (vol %). Glass transition temperature ( T g ), melting temperature ( T m ), and melting flow index (MFI) of the polymer matrix are T g ≈ −75 °C, T m ≈ 90 °C, and MFI ≈ 150 (g/10 min), respectively . Figure depicts the distribution of the particles sizes obtained from transmission electron microscopy (TEM) observations .…”

“…Next, these pellets were extruded into tapes. Samples were subsequently press molded at 180 °C during 30 min and degassed under reduced pressure in an oven at 80 °C during 24 h . Table summarizes the densities of the samples versus the CB volume fractions.…”