Hybrid calotropis gigantea fibre-reinforced epoxy composites with SiO2’s longer-term moisture absorbable and its impacts on mechanical and dynamic mechanical properties

Abstract

Opportunities for the fabrication of plant fiber hybrids using thermoplastics and thermosets may be found in a variety of industries, including automobiles and agriculture. This can lessen reliance on crude oil, which contributes to a number of sustainability problems. In the current study, calotropis gigantea fiber (CGF) and nanosilicon dioxide (SiO _2 )-derived hybridized materials’ mechanical, dynamic mechanical, and water absorption properties were examined. Utilizing varying weight proportions of nanoSiO _2 (0, 1.5, 3, and 4.5 wt%) and 30 wt% of CGF, we manufactured the composite using the hand lay-up method. The moisture absorption of the manufactured composites was measured during periods of 500, 1000, and 2000 h. For composite materials containing 1.5 wt% SiO _2 , the highest interlaminar shear strength (ILSS) failure point was 12.52 MPa for 500 h, which is 12.32% lower than the breaking strength for dried products (14.28 MPa). In comparison to the dry specimens, the bending strength of hybrids with 1.5% SiO _2 that were immersed in water for 500, 1000, and 2000 h decreased by 2.56%, 5.21%, and 9.65%, respectively. The storage modulus of the damp hybrids with 3% and 4.5 wt% SiO _2 was higher than that of the dry samples in terms of their dynamic mechanical properties. While the inclusion of nano-SiO _2 significantly reduced water absorption and moisture diffusion, especially for hybrid materials with 4.5 weight percent SiO _2 , the water-absorption behaviour of hybrid natural fiber materials followed the Fickian law. With prolonged exposure time, the mechanical properties of the nanocomposite, both with and without nano-SiO _2 , such as ILSS and bending strength, declined. Due to the effective distribution of filler in the matrices, the samples with 4.5 weight percent SiO _2 exhibited the smallest drop in strengths for both the flexural and interlaminar examinations, although all of them remained stronger than the CGF blends. The outcomes of the study point to potential applications in areas such as automobile manufacture, agriculture, construction, and general manufacturing.

Keywords

• hybrid composites
• mechanical properties
• nanocomposites
• moisture absorption
• calotropis gigantea fiber
• nanoSiO2