Effects of Chain Length, Stretching, and Molecular Groups on the Thermal Conductivity of Single Crosslinked Epoxy Resin Chains

XC Liu and X Yu and Z Yang and XR Zhuang and H Guo and XL Luo and JY Chen and YZ Liang and Y Chen, JOURNAL OF ELECTRONIC MATERIALS, 52, 2831-2842 (2023).

DOI: 10.1007/s11664-023-10246-8

The ultralow thermal conductivity (TC) (0.1-0.3 W m(-1) K-1) of amorphous epoxy resins (EPs) limits their applications to high heat flux; thus, designing EPs with high TC is of great significance. In this work, the individual and synergistic effects of three different factors, chain length, tensile strain, and curing agent structures, on the intrinsic TC of single crosslinked EP chains were investigated mainly by equilibrium molecular dynamics simulations. The results show that, compared with the linear polyethylene chain, EP chains in the unstretched state retain a much lower TC below 3 W m(-1) K-1 due to the more significant phonon scattering in the complex crosslinked structures. The TC can be significantly improved over a critical tensile strain due to the significant reduction in the folding and kink structures. The critical tensile strain varies with the types of crosslinked EP chains. A high TC of EP chains can be easily achieved due to the synergistic effect of chain length and stretching. By constructing two types of structural evolutions, the molecular structure of the curing agents was found to have a significant effect on the TC of crosslinked EP chains. The additional functional groups on the benzene ring cause a significant reduction in the TC of single EP chains. In addition, the decrease rate generally slows down as the benzene ring number increases.

Return to Publications page