Effects of carbon fillers on the thermal conductivity of highly filled liquid‐crystal polymer based resins

Abstract

The thermal conductivity of insulating polymers can be increased by the addition of conductive fillers. One potential market for these thermally conductive resins is for fuel cell bipolar plates. In this study, various amounts of three different carbon fillers (carbon black, synthetic graphite particles, and carbon fiber) were added to Vectra A950RX liquid crystal polymer. Because the resulting composites were anisotropic, they were tested for both through-plane and in-plane thermal conductivities. The effects of single fillers and combinations of the different fillers were studied via a factorial design. Each single filler caused a statistically significant increase in composite through-plane and in-plane thermal conductivities at the 95% confidence level, with synthetic graphite causing the largest increase. All of the composites containing combinations of the different fillers caused statistically significant increases in the composite through-plane and in-plane thermal conductivities. It is possible that thermally conductive pathways were formed that linked these carbon fillers, which resulted in increased composite thermal conductivity. Composites containing 70, 75, and 80 wt % synthetic graphite and the composite containing all three fillers (2.5 wt % carbon black, 65 wt % synthetic graphite, and 5 wt % carbon fiber) had in-plane thermal conductivities of 20 W m 21 K 21 or higher, which is desirable for bipolar plates.

Synergistic effects of graphene nanoplatelets in thermally conductive synthetic graphite filled polypropylene composite

“…Typical thermal conductivity values of some common thermoplastics are usually between 0.1 and 0.4 W/mK . To improve the thermal conductivity of a polymeric material, polymer matrices are usually filled with thermally conductive fillers such as metal powders , ceramic powders , and carbon‐based materials .…”

Effect of orientation and content of carbon based fillers on thermal conductivity of ethylene‐propylene‐diene/filler composites

“…It has been reported that the use of a mixture of filler materials increases thermal conductivity of polymer/filler composites. 15,19,20 Therefore, in this study, the effect of graphite/carbon fiber, graphite/MWCNT, and carbon fiber/MWCNT mixtures on parallel thermal conductivity of the oriented composites is investigated as shown in Figure 10. Total content of fillers in Figure 10 is fixed at 10%.…”

Fabrication of graphite/MgO-reinforced poly(vinyl chloride) composites by mechanical activation with enhanced thermal properties

“…[13][14][15][16] However, its poor thermal conductivity (0.014 W m À1 K À1 ) is a major disadvantage that hinders the widespread applications of PVC. 17,18 If a PVC-based material is modied by lling with thermally conductive agents that replace the expensive metals, it would concomitantly enhance the cost effectiveness and broaden the spectrum of applications for PVC to areas like heat transfer, electronic packaging, and architectural coverings. 2 Traditional methods for improving the thermal properties of conductive polymer composites include in situ polymerization, 19 solution blending 20 and melt-mixing.…”