The mechanical behavior of silane-modified nano–Al₂O₃/ basalt fiber/ polymer composite materials

In this research, the impact of modified alumina nanoparticles on tensile and flexural properties of basalt fibers-epoxy composites was experimentally examined. First, composite without alumina nanoparticles (neat sample) and composites with different loading of alumina nanoparticles (0.5, 1, 3, and 5 wt%) were manufactured. For the purpose of having a better interaction of alumina nanoparticles with the matrix, the surface of alumina nanoparticles was modified by the silane coupling agent (3-methoxysilyl-propylamine (3-APMS)). Fourier transform infrared (FT-IR) spectrum validated the reaction mechanism between the silane compound and alumina nanoparticles. 3-APMS/alumina nanoparticles were added to the epoxy resin through mechanical and ultrasonic methods. The resulting mixes were then used to make alumina nanoparticles/woven basalt fibers-epoxy composites utilizing the hand-layup methods. The mechanical properties of the composites were studied under tensile and three-point bending tests. Also, field emission scanning electron microscope (FESEM) was employed to investigate the dispersion of alumina nanoparticles in the matrix and the fracture surfaces of specimens. The results showed that the dispersion of 1 wt% modified nano-alumina, flexural strength, tensile strength, flexural modulus, and tensile modulus enhanced by 15.3, 14, 19.1, and 15.8%, respectively, compared with a neat sample. The microscopic investigations verified that adding the 3-APMS/alumina nanoparticles to the matrix of basalt fibers-epoxy composites enhances the basalt fibers-matrix interface, resulting in improved mechanical properties.