Mechanical, ballistic impact, and water absorption behavior of luffa/graphene reinforced epoxy composites

Abstract

The mechanical, ballistic, and moisture intake properties of luffa fiber reinforced with graphene-modified epoxy composites were experimentally investigated. The nanofiller graphene particles were modified with a matrix using the mechanical stirring process. The filler (graphene) of size 20 nm is modified with the matrix of different weight percentages 0, 1, 2, 3, and 4. The samples for various testings were prepared with different compositions using a hand layup technique followed by compression molding. The results show that tensile, impact, and flexural strength were enhanced with the modification of the filler graphene up to 2 wt%. The ballistic impact results show that energy absorption increases with nanofiller modification. Minimum water intake behavior is observed for the composite samples incorporated with fillers. Failure mechanisms were studied on tensile tested specimens using a scanning electron microscopy. The morphological images showed defects like interfacial behavior, fiber pull out, voids, and internal cracks on the tested specimens. K E Y W O R D S ballistic impact behavior, composite material, graphene, Luffa cylindrica, mechanical properties 1 | INTRODUCTION Owing to their ecofriendly character, low cost, and availability, natural fibers created interest among researchers for producing sustainable polymer composites. [1] As the world is focusing on reducing the effect of greenhouse gasses in the atmosphere, the demand for using natural fibers as reinforcements increased. [2,3] Inorganic fibers like carbon, aramid, and glass fibers have good attractive properties that make them ideal for use as reinforcements in polymer composites. [4] Nevertheless, synthetic fibers suffer from nonbiodegradability, high cost, and hazardous gasses during disposal, which made researchers find new alternative materials. [5] Hence, they tried to use natural fibers as alternative materials to overcome the problems of using synthetic fibers. [4,6] Natural fibers like sisal, [7] banana, [8-11] jute, [12-14] coir, [15,16] luffa, [17,18] hemp [19] and flax, [9,20] and so forth are most commonly used as reinforcements in polymer composites and those materials were used in various interior applications such as furniture, acoustics, vibration isolation, packaging, automobile industries, aeronautical, and marine sectors. [21,22] Their hydrophilic nature reduced compatibility, reinforcing effect, and stress transfer with polymer matrices made the natural fiber composites fit for use in light load and interior applications. The properties and quality of composites depend on the degree of compatibility between the matrix and natural fiber. [23-25] To enhance the bonding between the matrix and fibers researchers used different methods, one of which is surface treatments. Generally, surface treatments like alkali, [3,6,26-28] silane, [29,30] benzoylation treatment, [6,31] and so forth are used for treating the fiber surface. Tolera A. Negawo et al [32] studied the influence of alkali

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

“…The decrease in water diffusion parameters, as seen in figures 13(a) and (b), supports this. The findings of this research's inquiry into water absorption characteristics are consistent with those published by Ashok et al [55] for luffa/epoxy composites containing graphene. Nevertheless, specimens containing 3 weight percent SiO 2 absorbed less water than 1.5 wt % of SiO 2 sample.…”

The effect of fiber stacking sequence on mechanical and morphological behavior of paddy straw/pineapple leaf fiber-reinforced ortho-laminated polyester hybrid composites

“…The five sets of impact test samples were prepared based on ASTM D 256-10, the size of (65.5 × 12.7 × 5) mm. 16 The impact test was completed using the XJJU-5.5 model, with a pendulum of the potential energy of 5.5 J and an impact speed of 4.5 m/s (Izod). Finally, the average impact strength values were noted.…”

“…S5 sample (paddy pulp)-reinforced polyester composite is 12 MPa only, which is very less in interfacial bonding and then decreases the tensile strength of the fabricated laminates. 16 The stress-strain graph was shown in Figure 7. Unidirectional composite laminates demonstrated the greatest resistance to applied force deformation.…”

“…This improves the strength of the composite and is the consequence of properly dispersing graphene throughout the matrix, it transfers a consistent load from resin to reinforcement. [16][17][18] The natural fiberreinforced polymer composites (NFRPCs) are superior tensile/flexural strengths and moduli can be attained with a 30-40% fiber weight fraction. The best fiber length for NFRPCs is between 20 and 50 mm, which can be employed to get excellent tensile and flexural properties.…”

Calotropis gigantea stem fiber reinforced thermoset plastics: Interlaminar shear strength and related tribo-mechanical properties

“…To weigh and design the appropriate amount of fiber, epoxy, and filler material, equation (1) was employed. 45,46 A motorized blender set to 2000 r/min was used to blend epoxy and LFA to create a homogeneous composition. The CGFs were initially placed inside a 300 mm × 300 mm × 3 mm mold cavity, and the homogeneous composition was discharged.…”