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The authors have investigated the use of silver nanomaterials as a filler in epoxy resin in an effort to identify a composite resin with a high thermal conductivity for application as a thermal interface material. It was determined that the addition of silver nanoparticle and silver nanowires both increased the thermal conductivity of the resin, but the silver nanowires caused a much more drastic increase. It was found that by using nanowires instead of nanoparticles, six times less silver can be used and the weight of the composite resin can be decreased by over fifty percent. It was concluded that silver nanowires could potentially be used to increase the thermal conductivity of polymer composites.
Conductive carbon fillers (carbon black, carbon fiber, and synthetic graphite particles) were added to Vectra A950RX liquid crystal polymer and the axial and radial thermal conductivities were determined experimentally for each composite. The addition of Thermocarb TC-300 synthetic graphite caused the largest increase in thermal conductivity, with in-plane thermal conductivity values reaching greater than 20 W/m K which is the minimum value for use in fuel cells. Mathematical models were also developed to estimate the in-plane and through-plane thermal conductivities for composites containing synthetic graphite, carbon fiber, and carbon black based on the experimental data.
High-density polyethylene-talc-carbon black composites were prepared with varying amounts of talc to determine its effect on the thermo-physical properties of the composites. Carbon black was added in a content of 3.5 wt. % because it was previously determined that the mechanical properties of the composites were depreciated at higher loadings. It was found that the addition of talc enhanced the mechanical properties, as well as the thermal conductivity, and thermal diffusivity. The specific heat of these composites decreased with increasing filler content.
Electronics packaging is fast paced area of research as scientists work to keep up with the new demands of smaller, more powerful electronic devices. In this study, researchers looked at how the manufacturing technique used to create vapour grown carbon nanofiber (VGCNF)/rubbery epoxy composites affects the thermal conductivity, electrical conductivity and mechanical properties of the final product. Samples were produced by one of three methods: mechanical mixing (MM), three-roll milling (RM), or combined sonication and mechanical mixing (CSM). Structural investigations revealed that the RM technique was much better at homogenously dispersing the fibers, and did a better job of breaking up agglomerates. The team concluded that the RM method is best for producing this type of polymer.
