Processability, mechanical properties, and electrical conductivities of carbon black-filled ethylene-vinyl acetate copolymers

Abstract

The objective of this study was to investigate the processability, mechanical properties, and electrical properties of carbon black‐filled ethylene‐vinyl acetate (EVA) copolymers with different melt flow indexes (MFIs) and vinyl acetate (VA) contents. The effects of carbon black on maximum temperature, equilibrium torque, equilibrium viscosity, and work energy were characterized in a Haake torque rheometer. These properties were found to increase with an increase in carbon black concentration. MFI was found to be the important factor in determining processing properties of the three different EVA resins. Mechanical properties, including tensile modulus, tensile strength at break, and elongation at break were evaluated and the results showed that tensile modulus was dominated by VA content. MFI was the primary factor influencing tensile strength and elongation at break. Volume and surface resistivity of blends were also studied. EVA with higher MFI and higher crystallinity provided a lower percolation concentration. Bound polymer could be used to explain the differences in viscosity and percolation between EVAs at different molecular weights. © 2000 John Wiley & Sons, Inc. Adv Polym Techn 19: 132–139, 2000

An Internally Heated Shape Memory Polymer Dry Adhesive

“…Carbon black is well known as an additive to confer electrical conductivity to polymers [20][21][22]. The critical concentration of CB necessary to enable conductivity in an insulating polymer is called the percolation threshold, and is dependent on a variety of factors, including the type of carbon black used, the polymer chemistry, and the method of mixing.…”

“…In addition to conferring electrical conductivity, adding CB to polymers is known to affect mechanical properties. Specifically, an increase in storage modulus and hardness are to be expected [21,22]. Dynamic mechanical analysis measurements of 10 and 20 wt% CB/SMP blends are compared with a non-doped control sample in Figure 6A.…”

Graphene-Like Layers from Unconventional Carbon Sources: New Perspectives on Hybrid Materials and π-system Synergisms

“…Comparable or even larger variations of electrical conductivity were reported also in experiments with CB filling polymeric or epoxy matrices (filling percentages of the order of 10% or less can lead to a conductivity increasing up to 10 order of magnitudes [91][92][93]). So strongly superlinear increasing trends with doping are usually attributed to percolation mechanisms.…”

Electrical conductivity and dynamic mechanical properties of silicon rubber-based conducting composites: effect of cyclic deformation, pressure and temperature

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