Electrical conductivity degradation of fatigued carbon black reinforced natural rubber composites: Effects of carbon nanotubes and strain amplitudes

Abstract

The fatigue of rubber products is usually accompanied by undesirable transformation in their properties. The present work was dedicated to the investigation of consequences of fatigue loading on volume electric conductivity of natural rubber (NR) reinforced with 30 phr of fillers composed from various weight combinations of carbon nanotubes (CNTs) and carbon black (CB). Special attention was paid to study the influence of CNTs content on residual electric conductivity and a possible mechanism of fatigue driven rearrangement of hybrid filler network inside of rubber matrix was propounded forward. An increase in the CNTs content over the complete range of concentrations, enhanced the conductivity of fabricated samples up to two orders of magnitude in comparison to rubber compounds without CNTs. All the samples were subjected to harmonic sinusoidal loading at a frequency of 5 Hz up to 10 5 loading cycles at three different strains of 0.1, 0.25 and 0.5. Despite very little transformation in the polymer matrix, fatigue caused a progressive degradation of conductivity with an increase in applied strain. It was also found that with the addition and a subsequent increase in the concentration of CNTs, the undesirable reduction of conductivity was significantly arrested. This novel finding added another number to the list of the outstanding properties of CNTs.

Enhanced positive temperature coefficient effect by crosslinking reaction for silicone rubber/carbon black composites with high pressure sensitivity

“…The crosslink density of the composites was tested by a swelling method. A round sample with 13 mm diameter was kept in toluene at room temperature for 72 h. The crosslink density was calculated according to the Flory-Rehner formula as shown in Equations ( 1) and (2) 25,26 : Ve is crosslink density of the composites (mol/cm 3 ), χ is the Flory-Huggins polymer-solvent interaction parameter (0.465). V s is molar volume of toluene (106.4 cm 3 /mol), v r is volume fraction of rubber in the swollen network.…”

Effect of the silane coupling agent on the physicomechanical properties of EPDM/SBR/AL2O3 rubber blend nanocomposites

“…Rubber blends based on nanomaterials have become a hot topic of research in recent years. Previously, nanomaterials, such as carbon nanotubes, 1,2 halloysite nanotubes, 3,4 nano-Al 2 O 3 , 5,6 silica nanoparticles, 7–9 graphene nanoplates, 10,11 titanium dioxide nanoparticles, 12,13 CaCO 3 nanoparticles, 14 graphene nanosheets, 15,16 and nano–zinc oxide 17,18 have been utilized to prepare rubber nanocomposites.…”

The Influence of Local Strain Distribution on the Effective Electrical Resistance of Carbon Black Filled Natural Rubber

“…Therefore, the local stress–strain behavior around the inhomogeneity is close to intrinsic strength, causing crack growth initiation, whereas future loading leads to its propagation up to total failure [ 10 ]. On the other hand, the geometry of the inhomogeneity and global loading conditions are the reason for local multiaxial deformation leading to re-arrangement of the filler network at the affected location [ 11 , 12 ]. Thus, an influence on EER behavior is expected objectively.…”