Investigation of the mechanical and physical properties of mesoporous silicon dioxide fillet epoxy composites

In this study, the effect of mesoporous silicon dioxide (M-SiO2) additives with different surface areas and pore diameters on the morphological and mechanical properties of epoxy composites was investigated. For this purpose, M-SiO2 particles with different pore diameters and surface areas were synthesized from polyethylene glycol (PEG) with three different molecular weights (PEG2000 (PEG2), PEG6000 (PEG6), and PEG35000 (PEG35) kDa) using the one-step sol-gel technique. The mixing of epoxy resin, hardener and M-SiO2 fillers, was carried out in a mould followed by using ultrasonic bath and mechanical stirrer. The mechanical properties of the composites, including hardness, tensile strength, elongation at break, and modulus of elasticity, were studied. FT-IR spectra and XRD patterns show that M-SiO2 is distributed homogeneously in the epoxy. The epoxy/PEG35M-SiO2 composites' tensile strength (8.7%) and modulus of elasticity (23.3%) increased with the addition of PEG35M-SiO2, however their elongation at break (5.1%) decreased.