Electric field and mechanical stretching-induced structural ordering and enhanced thermal conductivity in epoxy resin

ABSTRACT Epoxy resin is crucial in thermal interface materials for integrated circuits, yet its thermal conductivity control remains unclear. In this study, equilibrium molecular dynamics simulations were employed to investigate the thermal properties of epoxy resin before and after polarisation and mechanical stretching. Notably, when fully polarised (E ≥ 12 V/nm), the polymer formed distinct layers, enhancing thermal conductivity by 1.94 times perpendicular to the field and reducing it by 0.28 times parallel to it, showing anisotropic behaviour. These findings demonstrate that the thermal conductivity of epoxy resin can be selectively modulated through electric field polarisation. Furthermore, different tensile forces are applied to the two ends of the molecular chains, causing the structures to gradually transform towards a crystalline morphology. When the strain reaches 0.8, the thermal conductivity in the stretching direction reaches 7.9 W/mK, which is 14.5 times higher than the unstretched system. Comprehensive analysis of system parameters before and after polarisation were analyzed, and the phonon transport characteristics of order polymer chains were reflected. This study provides new insights into the relationship between structural order and thermal transport, highlighting the potential of this approach as a rapid, filler-free modulation strategy.