High Thermal Conductivity of Bulk Epoxy Resin by Bottom-Up Parallel- Linking and Strain: A Molecular Dynamics Study
SH Li and XX Yu and H Bao and N Yang, JOURNAL OF PHYSICAL CHEMISTRY C, 122, 13140-13147 (2018).
The ultralow thermal conductivity (similar to 0.3 W m(-1) K-1) of amorphous epoxy resins significantly limits their applications in electronics. Conventional top-down methods, e.g., electrospinning, usually result in the aligned structure for linear thermoplastic polymers, thus satisfactory enhancement on thermal conductivity, but they are deficient for thermoset 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 unstretched parallel-linked epoxy resin as 0.80 W m(-1) K-1, more than 2-fold higher than that of amorphous structure. Furthermore, by applying uniaxial tensile strains along the intrachain direction, a further enhancement in thermal conductivity was obtained, reaching 6.45 W m(-1) K-1. Interestingly, we also observed that the interchain 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 W m(-1) K-1. Our study may provide a new insight into the design and fabrication of epoxy resins with a high thermal conductivity.
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