Influence of Nano-Silica on Enhancing the Mechanical Properties of Sisal/Kevlar Fiber Reinforced Polyester Hybrid Composites

In the fabrication of Sisal/Kevlar/Nano-silica reinforced polyester composites, the ultrasonic vibration was used in mixing the Nano-silica in polyester resin in which ultrasonic frequency of 15 kHz and with an 800 W power capacity was used. For uniform mixing of the nanoparticle in resin, an Ultrasonic probe was used. The Mechanical Properties of Sisal/Kevlar fiber, which are in mat form reinforced with polyester/Nano-silica, have been characterized. These composites have been fabricated using hand lay-up techniques by different wt.% of Nano Silica and different stacking sequences of fiber. The different wt.% are 2, 4, and 6 wt.%, and different stacking sequences are KSKS, SKKS, KSSK. The impact of the sonication effect on the mechanical properties was examined and compared. The addition of 4 wt% of Nano-silica in KSSK reported an increase of 23% of tensile strength, and 36% of flexural strength was observed. In KSKS, hybrid composites due to 4 wt.% silica addition 33% in tensile strength and 37% of flexural strength increases are found. The maximum tensile strength is obtained at 4 wt.% of Nano silica-reinforced with polyester with the stacking sequence KSSK and maximum flexural strength at 4 wt.% of Nano- silica with the stacking sequence KSKS. SEM analysis is also carried for the tested samples for failure analysis.