Effect of nanosized carbon black on the morphology, transport, and mechanical properties of rubbery epoxy and silicone composites

Abstract

Three different types of nanosized carbon black (CB), Printex XE2 (CBP), Vulcan XC72, and Printex 140 U (CBU), were dispersed by mechanical mixing in rubbery epoxy (RE) and silicone to produce composites. It was found that the maximum possible loading of CB in the polymers depended on the surface area of CB. For a given loading, all three CBs produced similar improvements in the thermal conductivity of the resulting composites, but their effects on the electrical conductivity varied and ranged from insulating composites with CBU to conducting composites with CBP. CBP produced a greater improvement in the electrical conductivity than the thermal conductivity of the polymers compared to the other CBs. This was attributed to the high structure of CBP, which led to the formation of a concatenated structure within the matrix. The CB/silicone composites had a similar thermal conductivity to that of the CB/RE composites, but only the CBP/silicone composite produced at 8 wt % loading was electrically conducting. The compression and hardness properties of RE were also significantly improved with the addition of CB. However, in the case of silicone, only CBP had a considerable effect on the compression properties. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Tailoring in thermomechanical properties of ethylene propylene diene monomer elastomer with silane functionalized multiwalled carbon nanotubes

“…Relatively low thermal conductivity of S‐MWCNTs compared to the carbon black, also imparts an important role to minimize thermal transport through the fabricated composite specimens. Thermal conductivity of EPDM composites is reduced with increasing environment temperature due to the activation of processing aids evaporation, polymer pyrolysis, and endothermic phenomena within the polymer nanocomposite …”

“…The addition of S‐MWCNTs in the host polymer matrix augments the rubber hardness due to strong interaction of nanotubes to polymeric chains of the EPDM. Another reason to enhance elastomeric hardness is reduction of chain mobility with increasing S‐MWCNTs concentration in the host matrix …”

Elastomeric ablative nanocomposites used in hyperthermal environments

“…The aforementioned property is diminished with increasing filler to matrix ratio and the maximum reduction is observed, i.e., 95% for E5 relative to base composite formulation (E1). The 1 wt% MWCNTs incorporated rubber nanocomposite has 29% improved thermal impedance compared to the E1 composition due to the excellent thermal stability, heat quenching through phonon entrapping, and the uniform dispersion of the nanotubes in the host polymer matrix . Thermal transport through a solid material strongly depends upon the anisotropic factor, ξ = k ‖ / k ⊥ ( k ⊥ and k ⊥ are the parallel and perpendicular thermal conductivity factors respectively).…”

“…Pyrolytic form of graphite has the highest value of the anisotropy factor of thermal conductivity among all natural existing materials ξ 300K = 342 . Thermal conductivity through the carbonaceous materials depends upon the particle size, form, and shape of carbon . Regardless of many similarities of heat flow mechanism in graphite and MWCNTs, a high density hexagonally packed MWCNT structure must have a much lower anisotropy of thermal and electrical conductivity due to a contribution of the circumferential bypass pathway to perpendicular thermal conductivity.…”

Mechanical and thermal performances of epoxy resin/graphitic carbon nitride composites

“…It has been studied to introduce zero‐dimensional particles and one‐dimensional fillers as reinforcements into EP to achieve the high performance . However, the poor combination between fillers and EP matrix limits the further performance improvement, especially in mechanical properties . In recent years, two‐dimensional (2D) materials, such as graphene oxide (GO), reduced graphene oxide (rGO), boron nitride (BN), and MoS 2 , have entered our field of vision .…”