High thermal conductivity of bulk epoxy resin by bottom-up parallel-linking and strain: a molecular dynamics study

TL;DR

This study uses molecular dynamics to demonstrate a bottom-up parallel-linking strategy and strain application that significantly enhances the thermal conductivity of epoxy resin, surpassing traditional methods.

Contribution

Introduces a novel bottom-up parallel-linking method and strain technique to substantially increase epoxy resin's thermal conductivity, providing new design insights.

Findings

Parallel-linking increases thermal conductivity to 0.80 W/mK

Strain boosts thermal conductivity up to 6.45 W/mK in bulk epoxy

Single chain thermal conductivity enhanced by 30 times to 33.8 W/mK

Abstract

The ultra-low thermal conductivity (~0.3 Wm-1K-1) of amorphous epoxy resins significantly limits their applications in electronics. Conventional top-down methods e.g. electrospinning usually result in aligned structure for linear polymers thus satisfactory enhancement on thermal conductivity, but they are deficient for epoxy resin polymerized by monomers and curing agent due to completely different cross-linked network structure. Here, we proposed a bottom-up strategy, namely parallel-linking method, to increase the intrinsic thermal conductivity of bulk epoxy resin. Through equilibrium molecular dynamics simulations, we reported on a high thermal conductivity value of parallel-linked epoxy resin (PLER) as 0.80 Wm-1K-1, more than twofold higher than that of amorphous structure. Furthermore, by applying uniaxial tensile strains along the intra-chain direction, a further enhancement in thermal conductivity was obtained, reaching 6.45 Wm-1K-1. Interestingly, we also observed that the inter-chain thermal conductivities decrease with increasing strain. The single chain of epoxy resin was also investigated and, surprisingly, its thermal conductivity was boosted by 30 times through tensile strain, as high as 33.8 Wm-1K-1. Our study may provide a new insight on the design and fabrication of epoxy resins with high thermal conductivity.