Study On Preparation And Properties Of Nano-Al₂O₃ Particle Reinforced Epoxy Resin Composites

TDE-85 epoxy resin methyltetrahydrophthalic anhydride (TDE-85/MeTHPA) cure system is a low viscosity epoxy resin matrix suiting filament wet winding. In order to improve their properties, the alumina nanoparticle reinforced TDE-85 epoxy resin composite were prepared by dispersing surface modification nano-Al2O3 particles with silane coupling agent (SCA) into epoxy resins through supersonic disperse instrument and mechanical blending, and the programmed temperature cure. Cure reaction, glass transition temperature and thermal degradation temperature were measured by differential scanning calorimetry (DSC); the temperature of deflection under load and the mechanical properties were also measured.The DSC results show that the activation energy is decreased and cure reaction rate is increased due to the hydroxyl of SCA. The molecule diffusion is affected by the addition of nano-Al2O3, thus the activation energy increased. Meanwhile, the reaction activity of epoxide groups and anhydride groups are decreased and some of the epoxide groups cannot react with anhydride groups due to the coupling of nano-Al2O3 and epoxy molecules. The cure reaction heat is reduced accordingly.SCA efficiently modified the surface of the nano-Al2O3. The surface modified nano-Al2O3 particles combine well with the matrix, so the tensile strength and impact strength are simultaneously improved. When 4wt% of SCA was added, the best surface modifying effect was gained. The tensile strength and elongation of composite are the highest when the nano-Al2O3 content was 2.5 wt%. The impact strength reached the highest when the nano-Al2O3 content was 3wt%, which was increased by 103%.Temperature of deflection under load were slightly reduced when the nano-Al2O3 content was 2~3wt%, while glass transition temperature were reduced a lot. Thermal degradation temperature and the activation energy of thermal degradation were reduced with the increase of the nano-Al2O3 content. All of these were the result of the decrease of the crosslink density resulted from the addition of nano-Al2O3.