Thermal stability and fracture toughness of epoxy resins modified with epoxidized castor oil and Al ₂O ₃ nanoparticles

This study examined the effects of the epoxidized castor oil (ECO) and Al ₂O ₃ content on the thermal stability and fracture toughness of the diglycidylether of bisphenol-A (DGEBA)/ECO/Al ₂O ₃ ternary composites using a range of techniques. The thermal stability of the composites was decreased by the addition of ECO and Al ₂O ₃ nanoparticles. The fracture toughness of the composites was improved significantly by the addition of ECO and Al ₂O ₃ nanoparticles. The composite containing 3 wt % Al ₂O ₃ nanoparticles showed the maximum flexural strength. Scanning electron microscopy (SEM) revealed tortuous cracks in the DGEBA/ECO/Al ₂O ₃ composites, which prevented deformation and crack propagation.