Epoxy-based composites with size-fractionated waste Areca sheath: an experimental investigation on the macroscopic and vibrational properties

The natural fibre composites present a realistic alternative to synthetic fibre-reinforced composites. Natural fibres offer notable benefits such as higher specific strength, reduced cost, biodegradability, renewability, and superior thermal and acoustic insulation properties [1]. Within a composite material, the reinforcement, often in the form of fibres or particulates, bears the load and inhibits the propagation of cracks within the polymer matrix [2]. Nature, in its abundance, provides the gift of plant fibre, serving as an organic reinforcement in various applications [3]. In recent years, researchers have been proactive in searching for eco-friendly fillers to enhance mechanical properties, leading to the identification of non-wood fibres, commonly referred to as lignocellulosic fibres [4]. Many research revealed that lignocellulosic fibres like jute, kenaf, bamboo, bagasse, hemp, coir, flax, ramie, sisal, et al., have already established their presence in the engineering sector, but they are derived from the plants directly [5, 6]. Hence, recent research has shifted its focus toward investigating lignocellulosic fibres derived from plant waste [7]. Areca is cultivated extensively in the tropical regions of South Asia for its fruit. In India, Areca thrives in regions such as Kerala, Karnataka, Assam, Tamil Nadu, Maharashtra, West Bengal, and, to a lesser extent, northeastern states [8]. Areca is a perennial and monoecious palm featuring male and female flowers on the same spadix. The cellulose content of areca sheath fibres ( $66\mathrm{\%}$$66\mathrm{\%}$66%66 \%$66\mathrm{\%}$ ) suggests that employing them as reinforcement material could yield favorable mechanical properties in composite materials [9]. Therefore, it is suitable reinforcement, which is thrown after its fruit cultivation.
The areca sheath fibre is brittle in nature, and embedding in a polymer matrix in the particulate form helps to improve dimensional stability during the manufacturing process [10]. In particulate form, the reinforcements range from milli- to micro- to nano-sized particles [11]. The strategic addition of varying proportions and sizes of reinforcements actively contributes to improvements in particulate composites' mechanical, thermal, and acoustic properties [12]. Common polymers used with lignocellulosic fibre are polyethylene, polyurethane, epoxy, vinyl ester, etc. Polymer-based composites are gaining attention in many fields, such as construction, automobile, defense, and packaging, due to their tailoring properties[13]. Thermoset polymer, like epoxy, has excellent mechanical properties and is preferred for industrial and household use[14]. The properties of epoxy include low coefficient of friction, rigidity strength, and modulus. Common reinforcements used in epoxy are fly ash, Glass micro balloons, carbon nanotubes, jute fibre, luffa fibre, and wood floor. In one research, Badyankal et al. [15] investigated the effect of fillers like Coconut shell (CS), Saw dust (SD), Kolam (KP), and Fly ash powder in epoxy resin and identified that Coconut shell (CS) fillers exhibit superior mechanical and wear properties compared to other fillers. CS-filled composites show enhanced tensile and flexural strength, improved fiber-matrix bonding, and reduced wear due to higher lignin content. Nowadays, fiber-reinforced and particle-reinforced composites, including micro- and nano-filled epoxy composites, are widely used in research to customize the performance of polymer composites for specific applications [16]. Due to its exceptional properties and widespread use in various areas, it has been selected as the matrix in this work.
The areca fruit husk fibre, when combined with unsaturated polyester resin through hand-laid compression molding, showcased promising results in mechanical tests adhering to ASTM standards. Notably, a composite featuring a $40\mathrm{\%}$$40\mathrm{\%}$40%40 \%$40\mathrm{\%}$ weight
ratio of areca husk fibre exhibited superior specific tensile strength compared to an unsaturated glass fibre polyester composite [17]. Another investigation on areca nut husk fiber shows that when it is mixed with mortar at $0.5\mathrm{\%}$$0.5\mathrm{\%}$0.5%0.5 \%$0.5\mathrm{\%}$, it enhances the mechanical properties and effectively mitigates shrinkage. However, higher areca nut husk fiber content increases porosity, though the overall strength remains above the control mix [18]. Another research into particulate composites, incorporating sunflower husk, hazelnut shell, and walnut shell in epoxy at different weight percentages, unveiled those reinforcements with lower aspect ratios displayed superior hardness and stiffness, owing to the lesser introduction of voids into the composites compared to higher aspect ratio reinforcements [19]. Investigations on epoxy composites reinforced with moringa oleifera fruit pods highlighted the advantages of employing pulverized particulate moringa oleifera over calcined counterparts, particularly in achieving superior fibre and resin bonding [20]. Similar research on bamboo-epoxy composites incorporating clamshell as a filler material revealed that adding clamshell reduces the void percentage while increasing the composite's density and hardness [21]. Investigation done on epoxy resin composites reinforced with wood apple shell particles has demonstrated significant enhancements in their mechanical and tribological properties, including tensile strength, flexural strength, and erosive wear resistance. Dynamic Mechanical Analysis reveals that increasing the weight percentage of wood apple shell particles improves viscoelastic stiffness [22]. Research on polypropylene composites incorporating Ponderosa pine wood flour revealed that increasing the aspect ratio of wood flour led to enhanced tensile and flexural strength and modulus, while an increase in particle size correlated with increased notched specimen impact energy but decreased unnotched specimen impact energy [23]. Another research study of short, randomly oriented sisal and banana fibres in polyester composites reveals that the free vibration characteristics of composites are notably affected by fibre weight percentage and fibre length [24]. Researchers explored the free vibration and damping characteristics of hybrid composites made from short-fibre chopped strand mats, clay, and vinyl ester. They found that the dispersion of nano clay significantly improves the internal damping properties of these composites [25]. Another study found that adding wire mesh and BaSO4 to aloe vera, flax, and hemp epoxy composites increased tensile and flexural strength, hardness, and natural frequency. The composite with both wire mesh and BaSO4 showed the best performance [26]. The literature on natural fibre composites is exciting; however, it appears that studies are missing on the use of waste areca sheaths to prepare composites, and limited research is available on the vibrational analysis of areca sheath composites for construction, automobile panel materials.
This study explores the potential of areca sheath micro-sized particulates in composite materials, addressing a key research gap. Three different micro-sized particulates of areca sheath-coarse, fine, and very fine(AS-C,F, VF)-were systematically prepared from the sheath for this purpose. Subsequently, AS-C, AS-F, and AS-VF-reinforced epoxy composites were fabricated using varying weight fractions (ranging from $5\mathrm{\%}$$5\mathrm{\%}$5%5 \%$5\mathrm{\%}$ to $20\mathrm{\%}$$20\mathrm{\%}$20%20 \%$20\mathrm{\%}$ ) of these particulates. The study investigates the influence of these particulates as reinforcement agents, with a comprehensive evaluation of their mechanical properties, including tensile, flexural, impact, hardness, and vibrational tests. The objective is to develop a composite material with enhanced properties suitable for diverse applications, particularly in infrastructure and automobile panel materials. The originality of this research lies in the novel use of areca sheath particulates in varying sizes and their systematic impact analysis, which has not been extensively explored in previous studies.

Areca sheaths were sourced from a local farm in Mangalore, India. The resin employed in this study consisted of Epoxy (L-12) and hardener (K-6) supplied by Atul Ltd., Gujarat, India, as shown in Fig .1. L-12 epoxy resin offers an affordable option with excellent resistance to environmental degradation, enhanced performance, and durability against thermal and water degradation. It's particularly well-suited for constructing building panels, especially for facades. The chemical composition of this resin is known as Diglycidyl ether of bisphenol-A [27], which is synthesized through the reaction between epichlorohydrin and bisphenol-A. Its structure is based on the condensation reaction of bisphenol-A and epichlorohydrin, resulting in a linear polymer chain with epoxy groups at each end. The hardener K-6 is a light-yellow aliphatic polyamine with a chemical name triethylene tetra amine designed for curing epoxy resin at room temperature. K-6 hardener is a useful and reliable curing agent that balances mechanical strength, thermal stability, and chemical resistance when used with compatible epoxy resins. It is widely used in engineering applications, including composite manufacturing and adhesives.

The collected areca sheath from farmland has been washed and soaked in water for a few days; as a result, the fibre extraction becomes easy. The fibres were removed using a metal brush and chopped into 10 to $50-\mathrm{mm}$$50-\mathrm{mm}$50-mm50-\mathrm{mm}$50-\mathrm{mm}$ lengths. It was then sun-dried and later in an incubator at ${70}^{\circ }\mathrm{C}$${70}^{\circ }\mathrm{C}$70^(@)C70^{\circ} \mathrm{C}${70}^{\circ }\mathrm{C}$ for 24 hours to remove all moisture. The density of the areca sheath particulate was determined in accordance with ASTM standard D792. The different lengths of areca sheath fibres have been taken for density measurement. The collected areca sheath fibres were cleaned with fresh water to eliminate dirt. Subsequently, these cleaned areca sheath fibres were stored and dried in an incubator at ${40}^{\circ }\mathrm{C}$${40}^{\circ }\mathrm{C}$40^(@)C40^{\circ} \mathrm{C}${40}^{\circ }\mathrm{C}$. Then, a mechanical pulverizer was employed to prepare particulates, followed by filtration using sieves with different mesh sizes ( $30,50,115$$30,50,115$30,50,11530,50,115$30,50,115$, and 200 ) to obtain particulates of varied sizes. These sieves were arranged in a specific order: 30 mesh ( $600\mu \mathrm{m}$$600\mu \mathrm{m}$600 mum600 \mu \mathrm{~m}$600\mu \mathrm{m}$ ) on top, followed by 50 mesh ( $300\mu \mathrm{m}$$300\mu \mathrm{m}$300 mum300 \mu \mathrm{~m}$300\mu \mathrm{m}$ ), 115 mesh ( $150\mu \mathrm{m}$$150\mu \mathrm{m}$150 mum150 \mu \mathrm{~m}$150\mu \mathrm{m}$ ), 200 mesh ( $75\mu \mathrm{m}$$75\mu \mathrm{m}$75 mum75 \mu \mathrm{~m}$75\mu \mathrm{m}$ ), and base at the bottom. The coarse particles were collected in a 50 mesh sieve, while the fine particulates were collected in a 115 mesh sieve, and the very fine particulates were collected in a 200 mesh sieve; the remaining particulates passed through the sieve and collected in the base. The sizes of the particulates were categorized based on the mesh size of the sieves. The particulates collected in a 50 mesh sieve were classified as AS-C ( $300-600\mu \mathrm{m}$$300-600\mu \mathrm{m}$300-600 mum300-600 \mu \mathrm{~m}$300-600\mu \mathrm{m}$ ), those in the 115 mesh sieve were labeled as AS-F ( $150-300\mu \mathrm{m}$$150-300\mu \mathrm{m}$150-300 mum150-300 \mu \mathrm{~m}$150-300\mu \mathrm{m}$ ), and the ones in the 200 mesh sieve were considered AS-$\mathrm{VF}(75-150\mu \mathrm{m})$$\mathrm{VF}(75-150\mu \mathrm{m})$VF(75-150 mum)\operatorname{VF}(75-150 \mu \mathrm{~m})$\mathrm{VF}(75-150\mu \mathrm{m})$, as illustrated in Fig.2.

A Leica optical microscope measured the geometric shape and aspect ratio of AS-C, AS-F, and AS-VF particulates obtained from a mechanical pulverizer. This process involves sequentially placing individual particulates onto a microscope stage, ensuring that the stage is cleared before each placement. Next,the light was turned on, and imaging began with the lower lens(4), with magnification progressively increasing to (500) using the higher lens. After image capture with a Leica optical microscope, aspect ratio measurements were conducted using ImageJ software. About 50 particulates in AS-C, AS-F, and AS-VF particulates have been measured for maximum and minimum dimensions.

Areca sheath particulates were ground into coarse, fine, and very fine sizes. To make the composite, the particulates were mixed with epoxy resin, and a hardener was added. First, a measured amount of epoxy and particulates was mixed in a beaker using a mechanical stirrer at 710 rpm for 50 minutes. After that, the hardener was added, and the mixture was stirred for another 8 minutes at 510 rpm . The mixture was then poured into silicone rubber molds to create a test specimen according to ASTM standards. The specimens were cured for 24 hours to harden. Once cured, they were carefully removed from the molds. Each specimen was labeled as Ep/AS-C/5 (Ep/AS stands for Epoxy/Areca Sheath, C stands for coarse, and 5 indicates the weight fraction of areca sheath). A specimen without any reinforcement particulates was also made. The details of all 12 specimens with different particulates are shown in Tab. 1.

The density of the composites was determined according to ASTM standard D792, using Archimedes' principle to measure the mass and weight of the specimens. Square specimens of $20\times 20\mathrm{mm}$$20\times 20\mathrm{mm}$20 xx20mm20 \times 20 \mathrm{~mm}$20\times 20\mathrm{mm}$ were prepared for density measurement, with distilled water as the immersion fluid at room temperature. The mass of each specimen was first measured using a digital balance with milligram precision. The specimen was then immersed in water, and its mass was measured again. The density of the composite specimen was calculated using the formula:

For the tensile test, composite specimens were prepared following the ASTM D3039 standards. The tests were conducted using the universal testing machine (UTM), ZWICK//ROELL Z020, equipped with a 10 kN load cell, as depicted in Fig. 3(a). The specimens were checked for cross-sectional area, and each prepared sample was placed individually in the machine's jaws. The test was carried out at a $2\mathrm{mm}/\min$$2\mathrm{mm}/\min$2mm//min2 \mathrm{~mm} / \mathrm{min}$2\mathrm{mm}/\min$ crosshead speed. The specimens were pulled until they broke, and the breaking point was identified. Final length, width, and thickness are measured from the vernier caliper. Multiple samples were prepared, and three specimens were tested for each set. The lateral strain was then calculated based on the final width of the specimen. Finally, the Poisson's ratio was calculated for each specimen. These specimens' average values were presented to ensure reliable and representative data.

The three-point bending test method was employed to determine the flexural strength and modulus of the developed composites. Following the ASTM-790 standard, the flexural test was conducted using a universal testing machine (UTM), ZWICK//ROELL Z020, equipped with a 10 kN load cell and the specimen, with beam-like dimensions of $150\times 12.7\times 3$$150\times 12.7\times 3$150 xx12.7 xx3150 \times 12.7 \times 3$150\times 12.7\times 3$ mm , as depicted in Fig. 3(b), was subjected to a load applied vertically at the center of the specimen until the specimen was broken. An extreme position was utilized as a sample support member during testing.

The Izod impact test was conducted to evaluate the impact resistance of the composites as per ASTM D4812-99 standards. In this test, an unnotched specimen, as per specifications, was securely fixed in the jaws, and a pendulum struck the specimen, measuring the energy absorbed by the specimen during fracture. The test apparatus used for this purpose was the ZWICK/ROELL Z020 HIT50P and specimens as illustrated in Fig. 3(c).

The Shore-D hardness test method specified in ASTM D-2240 was employed to measure the hardness of the composites. A durometer indenter was attached to a spring and indented at three different places on the composites. The average value of these measurements was taken for the analysis of composites. The Shore-D hardness test method is particularly suitable for polymer composites, as the indentation depth is directly proportional to the hardness measurement, allowing for easy and accurate measurement.

Experimental modal analysis is utilized to extract fundamental parameters such as natural frequency and modal damping relating to the dynamic behavior of structures. Experimental modal analysis is conducted using an impulse hammer test. The schematic diagram in Fig. 4 illustrates the setup for the free vibration test. The study analyzes the natural frequency and modal damping factors associated with the various particulate composite materials, including size factors and different weight fractions. The impact of the size factor of areca sheath particulate on composites and the influence of weight fraction composites are examined. These analyses are performed on beam-like composite specimens under clamped-free boundary conditions configurations. To determine the natural frequency of a particulate composite specimen measuring $210\times 12.5\times 4\mathrm{mm}$$210\times 12.5\times 4\mathrm{mm}$210 xx12.5 xx4mm210 \times 12.5 \times 4 \mathrm{~mm}$210\times 12.5\times 4\mathrm{mm}$, fixed on a rigid support, a single-axis accelerometer (Kistler 8730A500) is fixed with the specimen using wax. The impact or displacement signal is then captured by the accelerometer and transmitted to the 4-channel data acquisition system. The time domain signal is transformed into a frequency response signal using the Fast Fourier Transform (FFT) algorithm. Within the LabView software, the frequency response values are directly measured for various particulate composite specimens, and the damping factor value is evaluated by the half-power bandwidth method.

In this analysis, the surface of the fracture in the tensile failure of different specimens was investigated to assess the composites' behavior directly. Studying fractography provides in-depth knowledge of the fracture mechanism, enabling a better understanding of the material's behavior under specific conditions. SEM (Scanning Electron Microscope) images were captured using the ZESIS, EVO MA18, Germany instrument at 10 kV . Since the samples were nonconductive, a gold
film was coated using a sputtering machine to make them conductive. After gold coating, the samples were placed in the SEM machine in a pressurized nitrogen environment for scanning.

The average result obtained from five samples of different lengths indicates that the areca fibre densities are approximately $0.91\mathrm{g}/{\mathrm{cm}}^3$$0.91\mathrm{g}/{\mathrm{cm}}^3$0.91g//cm^(3)0.91 \mathrm{~g} / \mathrm{cm}^{3}$0.91\mathrm{g}/{\mathrm{cm}}^3$. Subramanyam et al. [28] measured the density of areca fibre as $0.90\mathrm{g}/{\mathrm{cm}}^3$$0.90\mathrm{g}/{\mathrm{cm}}^3$0.90g//cm^(3)0.90 \mathrm{~g} / \mathrm{cm}^{3}$0.90\mathrm{g}/{\mathrm{cm}}^3$, whereas Nayak et al. [29]. reported a density of areca sheath fibre as $1.040\mathrm{g}/{\mathrm{cm}}^3$$1.040\mathrm{g}/{\mathrm{cm}}^3$1.040g//cm^(3)1.040 \mathrm{~g} / \mathrm{cm}^{3}$1.040\mathrm{g}/{\mathrm{cm}}^3$. This difference may be attributed to fibre voids, growth location, maturity, and porosity.

Particle size distribution from the sieve shaker conveys the percentage of particulates retained on different-sized sieves, as illustrated in Fig.5. A maximum weight % distribution was attained in the range of AS-C particulates. The optical images present three distinct pulverized particulate sizes, as shown in Fig. 6.

These images highlight the geometric shape of the particulates. As the particulate size decreases due to the pulverization process, the morphology undergoes a transformation from evan flat fibres to irregular flat surfaces. The shape of AS-C, ASF, and AS-VF resembles the structure of chopped fibres. Based on the ASTM standard F 1877-05, they come under sharps and shards of rectangular fibres. The aspect ratio of the AS-C and AS-F particulate sizes surpass that of the AS-VF particulate sizes. Its difference is very small, as shown in Fig.6. The aspect ratio of the particles is the ratio of the longest dimension to the shortest dimension of the particles. These particulate aspect ratios were measured using ImageJ software. The aspect ratio maximum range for the AS-C comes at $3-4$$3-4$3-43-4$3-4$; for the AS-F, its maximum range is $2-3$$2-3$2-32-3$2-3$; and for the AS-VF, it spans from 1-2.

A natural fibre's performance in composite material depends mainly on its aspect ratio, fibre-matrix interaction, fibre surface area, chemical composition, growing condition, and how that fibre or fibre/matrix performs under a given set of environmental conditions. The aspect ratio of natural fibre should be optimum, and then the stress transfer should be maximum in the particulate composite. If the aspect ratio value is less than its optimum or greater, the stress value decreases and is added without any advantages in composites.

The density of particulate composites was measured and represented in Fig.8. However, it is noteworthy that the rate of density reduction is more pronounced in the very fine particulate areca sheath composites(Ep/AS-VF), potentially indicating a higher presence of voids in these composites because as the surface area of particulate increased, the resin could not cover its surface completely. This might show that the density of $\mathrm{Ep}/\mathrm{AS}-\mathrm{VF}$$\mathrm{Ep}/\mathrm{AS}-\mathrm{VF}$Ep//AS-VF\mathrm{Ep} / \mathrm{AS}-\mathrm{VF}$\mathrm{Ep}/\mathrm{AS}-\mathrm{VF}$ is low compared to fine particulate areca sheath composites (Ep/AS-F) and coarse particulate areca sheath composites (Ep/AS-C) at high-weight fractions. For the Ep/ASVF, the density started at $1.156\mathrm{gm}/\mathrm{cm}3$$1.156\mathrm{gm}/\mathrm{cm}3$1.156gm//cm31.156 \mathrm{gm} / \mathrm{cm} 3$1.156\mathrm{gm}/\mathrm{cm}3$ at $5\mathrm{\%}$$5\mathrm{\%}$5%5 \%$5\mathrm{\%}$ weight fraction and gradually decreased to $1.0688\mathrm{gm}/\mathrm{cm}3$$1.0688\mathrm{gm}/\mathrm{cm}3$1.0688gm//cm31.0688 \mathrm{gm} / \mathrm{cm} 3$1.0688\mathrm{gm}/\mathrm{cm}3$ as the weight fraction increased to $20\mathrm{\%}$$20\mathrm{\%}$20%20 \%$20\mathrm{\%}$. The density of $\mathrm{Ep}/\mathrm{AS}-\mathrm{VF}/20,\mathrm{Ep}/\mathrm{AS}-\mathrm{F}/20$$\mathrm{Ep}/\mathrm{AS}-\mathrm{VF}/20,\mathrm{Ep}/\mathrm{AS}-\mathrm{F}/20$Ep//AS-VF//20,Ep//AS-F//20\mathrm{Ep} / \mathrm{AS}-\mathrm{VF} / 20, \mathrm{Ep} / \mathrm{AS}-\mathrm{F} / 20$\mathrm{Ep}/\mathrm{AS}-\mathrm{VF}/20,\mathrm{Ep}/\mathrm{AS}-\mathrm{F}/20$, and $\mathrm{Ep}/\mathrm{AS}-\mathrm{C}/20$$\mathrm{Ep}/\mathrm{AS}-\mathrm{C}/20$Ep//AS-C//20\mathrm{Ep} / \mathrm{AS}-\mathrm{C} / 20$\mathrm{Ep}/\mathrm{AS}-\mathrm{C}/20$ were 1.0688, 1.091, and 1.105 $\mathrm{gm}/\mathrm{cm}3$$\mathrm{gm}/\mathrm{cm}3$gm//cm3\mathrm{gm} / \mathrm{cm} 3$\mathrm{gm}/\mathrm{cm}3$. This is because as areca sheath particulate size decreased, smaller particulates agglomerated and became bigger. Reinforcement of agglomerated particulates has the ability to create void and discontinuous phases within the epoxy resin.

This study utilized three different particulate sizes-AS-C,AS-F and AS-VF-to prepare composites with a $5\mathrm{\%}$$5\mathrm{\%}$5%5 \%$5\mathrm{\%}$ to $20\mathrm{\%}$$20\mathrm{\%}$20%20 \%$20\mathrm{\%}$ weight fraction of areca sheath particulates. Stress-strain graphs for different particulate composites are presented in Fig.9. The graphs reveal that the composites failed under tensile loading through brittle fracture. The Ep/AS-VF failed earlier than the Ep/AS-F and Ep/AS-C. These tensile failures depend on many factors, such as particle size or aspect ratio, concentration, adhesion at the particle-matrix interface, and the composite's microstructure[30]. AS-C size has a higher aspect ratio than AS-F and AS-VF sizes, which contributes to better load-transferring capacity in Ep/AS-C.

However, the tensile strength values were lower than the control in Ep/AS-F and Ep/AS-VF. This discrepancy is attributed to insufficient stress transfer from resin to reinforcement. In contrast, the tensile strength of the Ep/AS-C/10 specimen was $9\mathrm{\%}$$9\mathrm{\%}$9%9 \%$9\mathrm{\%}$ higher than the control, showcasing that natural fibre with good aspect ratio particulates used as filler in epoxy resin increases tensile strength at $10\mathrm{\%}$$10\mathrm{\%}$10%10 \%$10\mathrm{\%}$ weight fraction. Stark et al[23]. reported that wood flour with the highest aspect ratio in polypropylene resin resulted in the highest tensile strength and modulus. The strain decreases as the weight fraction of the areca sheath particulate increases in Ep/AS-F and Ep/AS-VF compared to the control specimen. This is because of the increase in AS-F and AS-VF in epoxy resin, resulting in the brittleness of particulate composites, further decreasing the lateral strain.

However, the tensile modulus values were higher for $\mathrm{Ep}/\mathrm{AS}-\mathrm{C}/5$$\mathrm{Ep}/\mathrm{AS}-\mathrm{C}/5$Ep//AS-C//5\mathrm{Ep} / \mathrm{AS}-\mathrm{C} / 5$\mathrm{Ep}/\mathrm{AS}-\mathrm{C}/5$ specimen to $\mathrm{Ep}/\mathrm{AS}-\mathrm{C}/10$$\mathrm{Ep}/\mathrm{AS}-\mathrm{C}/10$Ep//AS-C//10\mathrm{Ep} / \mathrm{AS}-\mathrm{C} / 10$\mathrm{Ep}/\mathrm{AS}-\mathrm{C}/10$ specimen particulate composite than for the Ep/AS-C/15 specimen(shown in Fig.10). In particular, Ep/AS-C/10 specimen exhibited a 14.37 % higher tensile modulus than the control, measuring 1050 MPa compared to 918 MPa in the control. This is because the Ep/ASC/10 specimen has the most effective load transfer between AS-C and epoxy resin. The highest aspect ratio rendered by AS-C might be the reason for the effective load transfer between them. The SEM images of the tensile tested Ep/AS-C/10 specimen are shown in Fig. 15(b), which show better bonding between resin and AS-C. The Ep/AS-C/5 specimen had a tensile modulus value of 680 MPa , which was $25.9\mathrm{\%}$$25.9\mathrm{\%}$25.9%25.9 \%$25.9\mathrm{\%}$ lower than the control. However, the tensile modulus values the Ep/AS-VF series, the Ep/AS-VF/5 specimen exhibits a tensile modulus of 332 MPa.This suggests that adding AS-VF decreases the stiffness of the composite. However, the Ep/AS-VF/10 specimen shows a slightly higher tensile modulus of 475 MPa , which is still a lower over control. In contrast, the Ep/AS-VF/ 15 sample has a tensile modulus of 335 MPa , representing a decrease in tensile modulus again compared to the control. In the Ep/AS-F series, the same trend is followed as Ep/AS-F because the low aspect ratio rendered by AS-F might be the reason for this low load transfer between them. Furthermore, the tensile modulus of Ep/AS-C/10 specimen exceeded the values of Ep/AS-F/10 and Ep/AS-VF/10 specimens. This reduction might be due to the specimen's brittleness, which reduces the load-bearing capacity and ductility. Flexural test of particulate composites
The influence of the areca sheath particulate on composites' flexural strength and flexural modulus follows a similar trend to the tensile properties, as shown in Fig.11. The Control, Ep/AS-F/5, Ep/AS-F/20, and Ep/AS-C/5 composites specimen flexural strength values as $31.4,37.99,32.451$$31.4,37.99,32.451$31.4,37.99,32.45131.4,37.99,32.451$31.4,37.99,32.451$ and 32.82 MPa while flexural modulus values as $2642.65,2928.29,2672.36$$2642.65,2928.29,2672.36$2642.65,2928.29,2672.362642.65,2928.29,2672.36$2642.65,2928.29,2672.36$, and 3043.29 MPa , respectively. The maximum flexural strength obtained at the Ep/AS-F/5 specimen and modulus obtained at $\mathrm{Ep}/\mathrm{AS}-\mathrm{C}/5$$\mathrm{Ep}/\mathrm{AS}-\mathrm{C}/5$Ep//AS-C//5\mathrm{Ep} / \mathrm{AS}-\mathrm{C} / 5$\mathrm{Ep}/\mathrm{AS}-\mathrm{C}/5$ specimen is $20.76\mathrm{\%}$$20.76\mathrm{\%}$20.76%20.76 \%$20.76\mathrm{\%}$ and $15.16\mathrm{\%}$$15.16\mathrm{\%}$15.16%15.16 \%$15.16\mathrm{\%}$ higher when compared to the control specimen. The AS-C, and AS-F has a high aspect ratio compared to the AS-VF sizes, which might bind with the resin together and transfer stress from resin to particulate effectively, resulting in improved flexural properties at 5 and $10\mathrm{\%}$$10\mathrm{\%}$10%10 \%$10\mathrm{\%}$ weight fraction. In each series, the flexural properties tend to decrease after a 10% weight fraction of resin and reinforcement. This might be due to bonding decreases
after this threshold, which impacts the overall flexural performance of the particulate composite. Migneault et al[31].reported that the higher the aspect ratio of fibre in resin, the better the stress transfer from resin to fibre compared to the lowest aspect ratio of fibre in resin. However, if the weight fraction is increased beyond $10\mathrm{\%}$$10\mathrm{\%}$10%10 \%$10\mathrm{\%}$, its strength and modulus decrease because wettability is decreased, and a discontinuous phase is created, which weakens the composites. For Ep/AS-VF series $\mathrm{Ep}/\mathrm{AS}-\mathrm{VF}/5$$\mathrm{Ep}/\mathrm{AS}-\mathrm{VF}/5$Ep//AS-VF//5\mathrm{Ep} / \mathrm{AS}-\mathrm{VF} / 5$\mathrm{Ep}/\mathrm{AS}-\mathrm{VF}/5$ and $\mathrm{Ep}/\mathrm{AS}-\mathrm{VF}/10$$\mathrm{Ep}/\mathrm{AS}-\mathrm{VF}/10$Ep//AS-VF//10\mathrm{Ep} / \mathrm{AS}-\mathrm{VF} / 10$\mathrm{Ep}/\mathrm{AS}-\mathrm{VF}/10$ specimen flexural strength and flexural modulus were $29.28,29.72\mathrm{MPa}$$29.28,29.72\mathrm{MPa}$29.28,29.72MPa29.28,29.72 \mathrm{MPa}$29.28,29.72\mathrm{MPa}$, and $2606.53,2426.20\mathrm{MPa}$$2606.53,2426.20\mathrm{MPa}$2606.53,2426.20MPa2606.53,2426.20 \mathrm{MPa}$2606.53,2426.20\mathrm{MPa}$, which is the maximum in its Ep/AS-VF series but lower than control, this shows that lower aspect ratio can't transfer load from resin to reinforcement effectively.
Similarly, $\mathrm{Ep}/\mathrm{AS}-\mathrm{F}/5$$\mathrm{Ep}/\mathrm{AS}-\mathrm{F}/5$Ep//AS-F//5\mathrm{Ep} / \mathrm{AS}-\mathrm{F} / 5$\mathrm{Ep}/\mathrm{AS}-\mathrm{F}/5$ and $\mathrm{Ep}/\mathrm{AS}-\mathrm{C}/5$$\mathrm{Ep}/\mathrm{AS}-\mathrm{C}/5$Ep//AS-C//5\mathrm{Ep} / \mathrm{AS}-\mathrm{C} / 5$\mathrm{Ep}/\mathrm{AS}-\mathrm{C}/5$ have shown the highest value of flexural strength and flexural modulus. Natural fibre particulate composite's flexural strength and modulus depend on various factors, including the aspect ratio of fibre particulates, fibre weight percent, fibre weight fraction, surface area of fibre, fibre cellulose content, and the bonding between the filler and resin[32]. Furthermore, the inclusion of areca sheath particulate in epoxy resin shows better results in $5\mathrm{\%}$$5\mathrm{\%}$5%5 \%$5\mathrm{\%}$ weight fraction at each category of particulate.

The energy that caused the dynamic failure of composites was measured using Izod impact tests. The crack propagation and initiation energy were evaluated using a notched and unnotched Izod specimen. Crack initiation happened at the composites due to the stress concentration of particulates of different weight fractions. The impact energy results of the unnotched specimen are shown in Fig.12(a), the impact strength properties of various particulate composites were compared against control, which has an impact energy of $23.44\mathrm{J}/\mathrm{m}$$23.44\mathrm{J}/\mathrm{m}$23.44J//m23.44 \mathrm{~J} / \mathrm{m}$23.44\mathrm{J}/\mathrm{m}$. In the Ep/AS-VF series, the Ep/AS-VF/5 specimen showed a noticeable improvement with an impact energy of $29.5\mathrm{J}/\mathrm{m}$$29.5\mathrm{J}/\mathrm{m}$29.5J//m29.5 \mathrm{~J} / \mathrm{m}$29.5\mathrm{J}/\mathrm{m}$, approximately a $25.89\mathrm{\%}$$25.89\mathrm{\%}$25.89%25.89 \%$25.89\mathrm{\%}$ increase over control. However, the $\mathrm{Ep}/\mathrm{AS}-\mathrm{VF}/10$$\mathrm{Ep}/\mathrm{AS}-\mathrm{VF}/10$Ep//AS-VF//10\mathrm{Ep} / \mathrm{AS}-\mathrm{VF} / 10$\mathrm{Ep}/\mathrm{AS}-\mathrm{VF}/10$ specimen increased to $34.54\mathrm{J}/\mathrm{m}$$34.54\mathrm{J}/\mathrm{m}$34.54J//m34.54 \mathrm{~J} / \mathrm{m}$34.54\mathrm{J}/\mathrm{m}$, indicating an impact energy enhancement of $47.38\mathrm{\%}$$47.38\mathrm{\%}$47.38%47.38 \%$47.38\mathrm{\%}$. The Ep/AS-VF/15 specimen exhibited a moderate improvement, with an impact energy of $24.92\mathrm{J}/\mathrm{m}$$24.92\mathrm{J}/\mathrm{m}$24.92J//m24.92 \mathrm{~J} / \mathrm{m}$24.92\mathrm{J}/\mathrm{m}$, representing a $6.31\mathrm{\%}$$6.31\mathrm{\%}$6.31%6.31 \%$6.31\mathrm{\%}$ increase over the control. This trend reversed with the Ep/AS-VF/20 specimen, significantly decreasing to $19.89\mathrm{J}/\mathrm{m}$$19.89\mathrm{J}/\mathrm{m}$19.89J//m19.89 \mathrm{~J} / \mathrm{m}$19.89\mathrm{J}/\mathrm{m}$.In the Ep/AS-F series, the Ep/AS-F/5 specimen had an impact energy of $25.6\mathrm{J}/\mathrm{m}$$25.6\mathrm{J}/\mathrm{m}$25.6J//m25.6 \mathrm{~J} / \mathrm{m}$25.6\mathrm{J}/\mathrm{m}$, which is a $9.22\mathrm{\%}$$9.22\mathrm{\%}$9.22%9.22 \%$9.22\mathrm{\%}$ increase from the control, suggesting that $5\mathrm{\%}$$5\mathrm{\%}$5%5 \%$5\mathrm{\%}$ particulate content might strengthen the composite. The Ep/AS-F/10 specimen similarly demonstrated a significant improvement, reaching $34.78\mathrm{J}/\mathrm{m},48.38\mathrm{\%}$$34.78\mathrm{J}/\mathrm{m},48.38\mathrm{\%}$34.78J//m,48.38%34.78 \mathrm{~J} / \mathrm{m}, 48.38 \%$34.78\mathrm{J}/\mathrm{m},48.38\mathrm{\%}$ higher than the control. Conversely, the Ep/AS-F/15 and Ep/AS-F/20 specimens had an impact energy of $20.65\mathrm{J}/\mathrm{m}$$20.65\mathrm{J}/\mathrm{m}$20.65J//m20.65 \mathrm{~J} / \mathrm{m}$20.65\mathrm{J}/\mathrm{m}$ and 19.92, an $11.90\mathrm{\%}$$11.90\mathrm{\%}$11.90%11.90 \%$11.90\mathrm{\%}$ and $15.01\mathrm{\%}$$15.01\mathrm{\%}$15.01%15.01 \%$15.01\mathrm{\%}$ decrease from control. The Ep/AS-C series exhibited the most substantial enhancements. The Ep/AS-C/5 and Ep/AS-C/10 specimens, with an impact energy of 44 and $54.7\mathrm{J}/\mathrm{m}$$54.7\mathrm{J}/\mathrm{m}$54.7J//m54.7 \mathrm{~J} / \mathrm{m}$54.7\mathrm{J}/\mathrm{m}$, represent an $87.75\mathrm{\%}$$87.75\mathrm{\%}$87.75%87.75 \%$87.75\mathrm{\%}$ and $133.24\mathrm{\%}$$133.24\mathrm{\%}$133.24%133.24 \%$133.24\mathrm{\%}$ increase from control. However, the Ep/AS-C/15 specimen significantly increased to $39.29\mathrm{J}/\mathrm{m}$$39.29\mathrm{J}/\mathrm{m}$39.29J//m39.29 \mathrm{~J} / \mathrm{m}$39.29\mathrm{J}/\mathrm{m}$, a $67.63\mathrm{\%}$$67.63\mathrm{\%}$67.63%67.63 \%$67.63\mathrm{\%}$ improvement. The Ep/AS-C/20 specimen, with an impact energy of 20.77 $\mathrm{J}/\mathrm{m}$$\mathrm{J}/\mathrm{m}$J//m\mathrm{J} / \mathrm{m}$\mathrm{J}/\mathrm{m}$, showed a minor decrease of $11.39\mathrm{\%}$$11.39\mathrm{\%}$11.39%11.39 \%$11.39\mathrm{\%}$. Stark et al[23]. conducted a study on wood-flour-filled polypropylene composites; the results reported that unnotched impact energy appeared to increase with the sizes of wood flour in polypropylene. For a high aspect ratio at lower particulate contents (e.g., $5-10\mathrm{\%}$$5-10\mathrm{\%}$5-10%5-10 \%$5-10\mathrm{\%}$ ), the bonding between the epoxy resin and the particulates can be strong, resulting in improved impact energy due to effective stress transfer from the matrix to the particulates. This is evident in the initial improvement in the Ep/AS-F/5 to Ep/AS-F/10 and Ep/AS-C/5 to Ep/AS-C/10 specimen. At the
same time, for low aspect ratio, the trend is similar,for instance, the Ep/AS-VF series shows significant improvements at low particulate weight fraction ( $5-10\mathrm{\%}$$5-10\mathrm{\%}$5-10%5-10 \%$5-10\mathrm{\%}$ ), indicating that the particulates used in this series are particularly effective at reinforcing the epoxy resin without causing detrimental effects like agglomeration or poor bonding.

The influence of the areca sheath particulate size on the hardness of the areca sheath particulate composite is shown in Fig.12(b). As the percentage of areca sheath particulate in epoxy increases, the hardness exhibits an ascending trend as the weight fraction of areca sheath particulate increases. The hardness of Ep/AS-C/5, Ep/AS-C/10, Ep/AS-C/15, and Ep/AS$\mathrm{C}/20$$\mathrm{C}/20$C//20\mathrm{C} / 20$\mathrm{C}/20$ composites specimen calculated from shore D methods was $84.2,85.8,87$$84.2,85.8,87$84.2,85.8,8784.2,85.8,87$84.2,85.8,87$, and 88 , respectively in the control specimen, its value is 83.8 . The maximum value is obtained in $\mathrm{Ep}/\mathrm{AS}-\mathrm{C}/20$$\mathrm{Ep}/\mathrm{AS}-\mathrm{C}/20$Ep//AS-C//20\mathrm{Ep} / \mathrm{AS}-\mathrm{C} / 20$\mathrm{Ep}/\mathrm{AS}-\mathrm{C}/20$. The increase in shore D hardness is because as the weight fraction of areca sheath particulate increases in epoxy resin, the penetration depth of the indenter decreases in the specimen. Compared to $\mathrm{Ep}/\mathrm{AS}-\mathrm{C}/20$$\mathrm{Ep}/\mathrm{AS}-\mathrm{C}/20$Ep//AS-C//20\mathrm{Ep} / \mathrm{AS}-\mathrm{C} / 20$\mathrm{Ep}/\mathrm{AS}-\mathrm{C}/20$, the hardness of $\mathrm{Ep}/\mathrm{AS}-\mathrm{VF}/20$$\mathrm{Ep}/\mathrm{AS}-\mathrm{VF}/20$Ep//AS-VF//20\mathrm{Ep} / \mathrm{AS}-\mathrm{VF} / 20$\mathrm{Ep}/\mathrm{AS}-\mathrm{VF}/20$ and AS-F/20 specimen values is 87 and 87.6 decreased, but no statistical difference was observed.

The setup of the impact hammer test and typical time and frequency response for a control specimen, as shown in Fig.13(a) & (b), reveals clear peaks in the frequency response curve that indicate the natural frequencies of the control specimen. The natural frequency of various particulate composites was compared to control, which has a natural frequency of 22 Hz . This baseline allows us to evaluate the effects of adding different types and amounts of particulates on the vibrational behavior of the composites.Fig.14(b) illustrates the influence of aspect ratio and weight fraction on particulate composites' fundamental natural frequency under clamped-free boundary conditions. The results indicate that the aspect ratio of the areca sheath particulates significantly influences the particulate composites natural frequency. Specifically, the Ep/AS-C category exhibits a higher natural frequency than other particulate composites, likely because its aspect ratio is higher than other AS-F and AS-VF. At the same time, $10\mathrm{\%}$$10\mathrm{\%}$10%10 \%$10\mathrm{\%}$ weight fractions particulate composites in each category show better natural frequency than lower weight fraction particulate composites such as Ep/AS-VF/20 show 8.33 % higher than Ep/AS-VF/5 similarly, Ep/AS-F/20 shows 8.69 % higher than Ep/AS-F/5. At the same time Ep/AS-C series showing opposite trends Ep/AS-C/5 shows $8\mathrm{\%}$$8\mathrm{\%}$8%8 \%$8\mathrm{\%}$ higher than Ep/AS-C/20. Ep/AS-C/10 and Ep/AS-F/10 have natural frequencies of 30, and 28 Hz , which is $36.36,27.27\mathrm{\%}$$36.36,27.27\mathrm{\%}$36.36,27.27%36.36,27.27 \%$36.36,27.27\mathrm{\%}$ higher than the control specimen, which is 22 Hz . Similarly, Ep/AS-VF/10 has a 28 Hz natural frequency, which is again $27.27\mathrm{\%}$$27.27\mathrm{\%}$27.27%27.27 \%$27.27\mathrm{\%}$ higher than the control specimen; this should be due to the optimum bonding in the Ep/AS-VF series.

Damping factor of particulate composites
The graph in Fig. 14 (a) is used to find damping factor values using the half-power bandwidth method. This figure shows how to find the half-power points by seeing where the line crosses the Frequency Response Function (FRF) curve. A is the highest point on the curve. The difference in frequency ( ${\omega }_1-{\omega }_2$${\omega }_1-{\omega }_2$omega_(1)-omega_(2)\omega_{1}-\omega_{2}${\omega }_1-{\omega }_2$ ) values where the curve is cut by a horizontal line drawn at $\mathrm{A}/\sqrt{2}$$\mathrm{A}/\sqrt{2}$A//sqrt2\mathrm{A} / \sqrt{2}$\mathrm{A}/\sqrt{2}$ below the peak. These half-power points help calculate the damping factor. The damping factor for various particulate composites is shown in Fig.14(c). The control, Ep/AS-VF/5, Ep/AS-F/5, and Ep/AS-C/5 show damping factor value has $0.1956,0.10416,0.1086$$0.1956,0.10416,0.1086$0.1956,0.10416,0.10860.1956,0.10416,0.1086$0.1956,0.10416,0.1086$ and 0.11 . The damping factor at lower weight fraction shows a lowest value because
the greater weight of resin present in the lower weight fraction of areca sheath particulates composite, which dissipates less energy. For the same weight fraction content(15%) in each category, particulate composite Ep/AS-VF/15,Ep/AS$\mathrm{VF}/20,\mathrm{Ep}/\mathrm{AS}-\mathrm{F}/15$$\mathrm{VF}/20,\mathrm{Ep}/\mathrm{AS}-\mathrm{F}/15$VF//20,Ep//AS-F//15\mathrm{VF} / 20, \mathrm{Ep} / \mathrm{AS}-\mathrm{F} / 15$\mathrm{VF}/20,\mathrm{Ep}/\mathrm{AS}-\mathrm{F}/15$ and $\mathrm{Ep}/\mathrm{AS}-\mathrm{C}/15$$\mathrm{Ep}/\mathrm{AS}-\mathrm{C}/15$Ep//AS-C//15\mathrm{Ep} / \mathrm{AS}-\mathrm{C} / 15$\mathrm{Ep}/\mathrm{AS}-\mathrm{C}/15$, has damping factor $0.1667,0.11530,0.15909$$0.1667,0.11530,0.15909$0.1667,0.11530,0.159090.1667,0.11530,0.15909$0.1667,0.11530,0.15909$ and 0.1304 . This shows that $\mathrm{Ep}/$$\mathrm{Ep}/$Ep//\mathrm{Ep} /$\mathrm{Ep}/$ ASF and $\mathrm{Ep}/\mathrm{AS}-\mathrm{VF}$$\mathrm{Ep}/\mathrm{AS}-\mathrm{VF}$Ep//AS-VF\mathrm{Ep} / \mathrm{AS}-\mathrm{VF}$\mathrm{Ep}/\mathrm{AS}-\mathrm{VF}$ have a better damping factor than Ep/AS-C in 15-20 % weight fraction because the void is created due to agglomeration, which increases the damping capacity of these composites.

The properties of composites are strongly dependent on the areca sheath particulate weight fraction, particulate size, and particulate distribution in epoxy resin. The fracture morphology analysis of the areca sheath particulate composites after tensile tests, obtained by scanning electron microscopy ZESIS, EVO MA18, Germany is presented in Fig.15. In Fig.15(a), the control specimen's fractured surface is very smooth, and the river lining pattern specifies that the fractured specimens are brittle. Therefore, the control specimen reveals a brittle fracture behavior. It can be observed that in Fig.15(b), the areca sheath particulate embedded in the epoxy resin, there is no evidence of areca sheath particulate debonding, which suggests the relatively strong bonding, but in Fig.15(c) specimen, the interfacial debonding and void formation occurs this might be due to less wettability of areca sheath particulates. The resin-rich zone was observed in a low weight fraction of areca sheath composites (as shown in Fig. 15(d) and (e)). The fractured surfaces are smoothly aligned, and scraps were observed. This indicates that the tensile strength of these specimens has decreased compared to the control. However, in Fig.15(f), AS-VF agglomerated up to several higher microns is observed. Besides, the void is also observed in the fractured surface, which may be caused by gas entrapped during manufacturing. The agglomeration of areca sheath particulate and the microstructure defects might explain the decrease in the tensile modulus of $\mathrm{Ep}/\mathrm{AS}-\mathrm{VF}/20$$\mathrm{Ep}/\mathrm{AS}-\mathrm{VF}/20$Ep//AS-VF//20\mathrm{Ep} / \mathrm{AS}-\mathrm{VF} / 20$\mathrm{Ep}/\mathrm{AS}-\mathrm{VF}/20$.

Tab. 2 presents data on the mechanical properties of various composite materials, which are fabricated by combining different types of particles (fillers) with polymer resin. The table highlights several key parameters: particle size, filler content, tensile strength, flexural strength, impact strength, and hardness. The particle sizes of the fillers used in the composites, as detailed in the table, range from $64\mu \mathrm{m}$$64\mu \mathrm{m}$64 mum64 \mu \mathrm{~m}$64\mu \mathrm{m}$ to $600\mu \mathrm{m}$$600\mu \mathrm{m}$600 mum600 \mu \mathrm{~m}$600\mu \mathrm{m}$, significantly impacting the mechanical properties of the materials.
Shakuntala et al. found that a 15 -weight fraction $\mathrm{\%}$$\mathrm{\%}$%\%$\mathrm{\%}$ of apple shell-reinforced epoxy composite, with a particle size of 212 $\mu \mathrm{m}$$\mu \mathrm{m}$mum\mu \mathrm{m}$\mu \mathrm{m}$, had the highest tensile and flexural strength. Conversely, Narlioglu et al. reported the lowest tensile and flexural strength in a 33-weight fraction % Fiberboard HDPE composite. In this study, an Ep/AS-C/10 showed a tensile and flexural strength that falls between the strengths of these two composites, indicating its potential for use in low-load building applications, Partition panels, Ceiling Panels, and similar applications. However, a notable issue with these particulate composites is that grinding the reinforcement to the microscale results in uneven particle sizes, which diminishes the load transfer capacity from the resin to the reinforcement. Moreover, the composite material does not possess the necessary mechanical properties for high-load applications.

The epoxy composites with areca sheath particulates ranging from 5 to $20\mathrm{\%}$$20\mathrm{\%}$20%20 \%$20\mathrm{\%}$ weight fraction were prepared. The study demonstrates that Ep/AS-C, significantly improve mechanical properties. The optimal tensile strength 24 MPa and modulus 1050 MPa were observed at a $10\mathrm{\%}$$10\mathrm{\%}$10%10 \%$10\mathrm{\%}$ weight fraction in the Ep/AS-C/10 composite. The highest flexural modulus 3043 MPa and impact energy $54.7\mathrm{J}/\mathrm{m}$$54.7\mathrm{J}/\mathrm{m}$54.7J//m54.7 \mathrm{~J} / \mathrm{m}$54.7\mathrm{J}/\mathrm{m}$ were recorded in the $\mathrm{Ep}/\mathrm{AS}-\mathrm{C}/5$$\mathrm{Ep}/\mathrm{AS}-\mathrm{C}/5$Ep//AS-C//5\mathrm{Ep} / \mathrm{AS}-\mathrm{C} / 5$\mathrm{Ep}/\mathrm{AS}-\mathrm{C}/5$ and $\mathrm{Ep}/\mathrm{AS}-\mathrm{C}/10$$\mathrm{Ep}/\mathrm{AS}-\mathrm{C}/10$Ep//AS-C//10\mathrm{Ep} / \mathrm{AS}-\mathrm{C} / 10$\mathrm{Ep}/\mathrm{AS}-\mathrm{C}/10$ composites. However, adding more than $10\mathrm{\%}$$10\mathrm{\%}$10%10 \%$10\mathrm{\%}$ particulates AS-C,F,VF led to a decline in tensile and flexural properties due to agglomeration and poor wettability. The Ep/AS-C/10 specimen exhibited the highest natural frequency 30 Hz . The composites also showed excellent hardness, with a maximum value of 88 shore D for $\mathrm{Ep}/\mathrm{AS}-\mathrm{C}/20$$\mathrm{Ep}/\mathrm{AS}-\mathrm{C}/20$Ep//AS-C//20\mathrm{Ep} / \mathrm{AS}-\mathrm{C} / 20$\mathrm{Ep}/\mathrm{AS}-\mathrm{C}/20$. These lightweight composites are promising alternatives to wood-based epoxy materials and are well-suited for low-load structural applications, including building panels and infrastructure like Partition panels, Ceiling Panels, and similar applications.

T his research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

Each specimen was labeled as Ep/AS-C/5 (Ep/AS stands for Epoxy/Areca Sheath, C stands for coarse, and 5 indicates the weight fraction of the areca sheath. The details of all 12 specimens with different particulates are shown in Tab. 3.

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