Dynamic mechanical properties of conductive carbon black‐reinforced closed cell microcellular oil‐extended EPDM rubber vulcanizates: Effect of blowing agent, temperature, frequency, and strain

Abstract

Dynamic viscoelastic properties of Vulcan XC 72 (excess conductive carbon black)-reinforced solid-and closed-cell microcellular controlled long chain branching grade oil-extended EPDM (Keltan 7341A) rubber vulcanizates were studied at four frequencies of 3. 5, 11, 35, and 110 Hz, and at a temperature range of Ϫ100 to 160°C.The effect of blowing agent (ADC 21) loading on storage modulus (EЈ) and loss tangent (tan ␦) was studied. The log of storage modulus bears a linear relationship with the log of density for both solid and microcellular rubber. Relative storage modulus (EЈ f /EЈ s ) decreases with decrease in relative density ( f / s ). Both EЈ and tan ␦ were found to be dependent on frequency and temperature. The master curves of the storage modulus versus log temperature-reduced frequency were formed by superimposing EЈ results and by using shift factors calculated by Arrhenius equation. Strain-dependent isothermal dynamic viscoelastic properties were carried out for dynamic strain amplitude of 0.08 -7%. Cole-Cole plots of microcellular vulcanizates show a circular arc with blowing agent (density). Empirical relationship between tan ␦ versus EЈ is found to be linear, whose slope is independent of blowing agent loading or density.

Structural, viscoelastic, and vulcanization study of sponge ethylene–propylene–diene monomer composites with various carbon black loadings

“…As a result, the loss modulus increased, and this led to an elevation in tan δ. This means that with nanocarbon incorporation into the polymer matrix, the viscoelastic nature of the fabricated composites decreased …”

“…Viscoelasticity is also a useful property associated with EPDM rubber. These materials exhibit both viscous and elastic behavior on deformation . The viscous part associated with the rubber behaves just like honey, as it resists shear flow, and the elastic part shows springlike behavior …”

The combination of expandable graphite, organic montmorillonite, and magnesium hydrate as fire‐retardant additives for ethylene–propylene–diene monomer/chloroprene rubber foams

“…Recently, rubber foam has been widely applied in a variety of industrial and commercial areas . Because it combines the strong initial adhesion, excellent oil resistance, chemical corrosion resistance, and flame retardance of chloroprene rubber (CR) with the excellent aging resistance, chemical resistance, electrical insulation, and low‐temperature flexibility of ethylene‐propylene‐diene monomer (EPDM), EPDM/CR foam has great potential for application …”

Rheological behavior of a microcellular, oil‐extended ethylene–propylene–diene rubber compound: Effects of the blowing agent curing agent, and conductive carbon black filler

“…Recently, the dynamic mechanical properties of conductive carbon black reinforced, closed-cell, microcellular, oil-extended EPDM vulcanizates have been studied. 25 The objective of this work was to study the rheological properties of a closed-cell microcellular rubber compound based on conjugated, long-chainbranch-grade, oil-extended EPDM (Keltan 7341 A) with the variation of the blowing agent loading in both unfilled and conductive carbon black filled systems. The effect of temperature in the extrusion was also studied.…”