Enhancement of the Mechanical and Thermal Properties in Epoxy Film Adhesive Using <scp>APTES</scp> ‐Modified Zirconia Nanoparticles: Thermal Degradation Kinetics Study

ABSTRACT This study presents the development of high‐performance nanocomposite epoxy film adhesives reinforced with surface‐modified zirconium oxide (ZrO2) nanoparticles using (3‐aminopropyl) triethoxysilane (APTES). The mechanical and thermal behaviors of the prepared films were systematically investigated. The sample containing 3 wt% ZrO2 (3ZR) showed optimal mechanical properties, with tensile strength, modulus, and toughness increased by 88%, 18%, and 45%, respectively, compared to neat epoxy. Higher nanoparticle contents (5–7 wt%) caused performance deterioration due to agglomeration. APTES modification (3APZr) further improved performance, enhancing tensile, shear strength, and toughness by 223%, 98%, and 54.5%, respectively. Fourier‐transform infrared spectroscopy (FTIR) and field‐emission scanning electron microscopy (FESEM) analyses confirmed the formation of interfacial crosslinking bonds and uniform nanoparticle dispersion in the epoxy matrix. Thermal degradation studies using Ozawa and Kissinger methods revealed that 3APZr exhibited the highest thermal stability with an activation energy of 433.24 kJ/mol. Overall, the incorporation of APTES‐functionalized ZrO2 nanoparticles offers an efficient strategy for developing epoxy film adhesives with superior mechanical and thermal performance, making them promising for advanced structural applications such as aerospace and automotive industries.