Influence of Morphology and Surface Modification of MgO on Thermal Characteristics of Epoxy Composite

The advancement in electronic device miniaturization has led to an increase in thermal issues. The reliability of these devices depends on heat dissipation, leading to the development of thermal interface materials (TIMs). In this study, the influence of morphology and surface modification on the thermal characteristics of magnesium oxide (MgO) incorporated epoxy composites was investigated. A wet precipitation method was employed for the synthesis of spherical S-MgO. However, oblong hexagonal H-MgO was obtained via a hydrothermal process. Fillers were functionalized with (3-Aminopropyl) triethoxysilane (APTES) to improve interfacial bonds. APTES modified oblong hexagonal MgO (AH-MgO) showed better thermal conductivity compared to APTES modified spherical MgO (AS-MgO). By the inclusion of 20 wt. % filler, the thermal conductivity of AH-MgO was enhanced ∼8.5 fold (1.88 W.m−1.K−1) compared to neat epoxy (0.2 W.m−1.K−1), which remains lower in AS-MgO ∼1.8 W.m−1.K−1 (8 fold). AH-MgO-Epoxy exhibits improved thermal stability with an activation energy (Ea) of 98.10 KJ mol−1 in comparison to AS-MgO-Epoxy (90.56 KJ mol−1). The oblong hexagonal structure of AH-MgO facilitates more phonon transportation due to the elongated thermal conductive paths. Moreover, surface modification further advances interface with the epoxy matrix. The developed composite can be use as alternative TIMs for electronic packaging.