Mechanical Strength and Water Absorption Analysis of Silane Treated Kenaf Natural Composites With Silicon Nanoparticles

This research is mainly focused on the analysis of tensile and �exural strength, water absorption angle measurement of untreated and silane treatment of natural kenaf �ber composites reinforced with silicon nanoparticles. The percentages of nano silicon were 0.5 wt%, 1.5 wt% and 2.5 wt%. Before reinforcement, the kenaf �ber was treated with silane solution ( 90 vol% of water and 10 vol% of pure silane) to enhance the bonding strength. The composites samples were prepared using Epoxy, Kenaf and Silicon nanoparticle (EKS) by the compression moulding process. The tensile and �exural strength were measured about automobile interior application. Moreover, the samples were immersed in water for 24 hours with different environmental conditions. The results indicated that the tensile strength of epoxy improved from 8-9% when increasing the nanoparticles. Also, it was found that 3-5% of strength enhancement in silane treated samples than untreated composites. Similarly, the �exural strength of silane treated samples were found higher about 4% than untreated samples. And, lower water absorption was noted with silane treated than untreated kenaf hybrid composites, which tends to improve the bonding. It causes improvements in mechanical strength with silane treated kenaf hybrid composites.


Introduction
The kenaf treated silicon-based hybrid composite materials are green composite materials, which are used in the protection of the environment [1].Natural bers are formed from renewable resources, and eco-friendly and relatively low-cost compared to other synthetic ber materials [2].The Pineapple leaf bers and citrus bers agriculture waste compared with tropical fruits, gives higher strength of mechanical properties [3].The maximum number of the automotive interior component was designed and manufactured for successful reinforcement of natural composites like thermoplastics and thermoset composite materials [4].But, natural composite ber materials have prepared in a limited amount of reinforcement and the nal output is the unpredictability in mechanical properties and water absorption behavior of composite matrix [5].In ax bers, composite materials have good potential compared with carbon bers, the more materials required to form ax bers [6].The woven-based hybrid composite materials have good Mechanical, Morphological, and Water absorption Properties [7].better results are experientially proved the highest value of tensile strength in non-woven and woven-based kenaf hybrid composite material [8].The surface-modi ed Luffa Cylindrica bre ber gives good mechanical and water absorption behavior because of percentages added reinforcement materials [9].Jute ber reinforcement of composite materials comprises in ber the maximum strength and highest bond into a matrix with the distinction between them [10].The long-term water absorption test performance reinforced composite materials with creative and solution modi ed for hemp bers in 3 re-agent inveterate that surface modi cations of ller in uence of water absorption process [11].The water absorption in bers and biocomposite has a major effect on their assets in properties and structures.With the increased uptake of moisture in reinforced hemp ber, the tensile and exural properties of unsaturated polyester composite have decreased [12].To explain the wetness, water absorption of composite ber materials, different models have been created [13].Chemical or physical ber surface treatment is used to decrease the maximum moisture or water inclusion llers in composite in various ndings have been reposted concerning the water absorbability of the composite [14].The chemical treatment has been reduced the overall water absorption of bers and may have a positive impact on the quality parameters of composite materials depending on plant and matrix form, brous ller treatment conditions [15].Amorphous elements such as in water storage, hemicelluloses also play a signi cant role.Higher hemicellulose bers more moisture-absorbing material.In hemp ber substantially minimum water droplets have been identi ed then, partial ber removal ability bers to absorb water is decreased [16][17].The natural ber extraction process can be carried out using various techniques, including mechanical, chemical, and biological methods.According to the amount of ber generated or the nature and properties of ber bundles obtained, each method poses various advantages or disadvantages.The sugar palm ber reinforced vinyl ester composite materials soil expanded water retention, heated in sugar palm ber composites, and simultaneously lowest mechanical properties of composite materials.Because of 200 hours soil buried also water absorption high range is 0.92 percentages.Vinyl ester in the percentage of 0.42 % [18].The impact values of Arenga pinnata ber treated added the epoxy resin composite developed because the bers are getting age limit, composite materials are shown to improve the plasticity however cut back in strength.many research has been conducted to search out the impact of chemical reaction of mechanical parameters sugar palm composite material [19].The ber will go about as transporters of reinforced ber when the ber strengthened composites are applied with the load.At that point, the pressure will move to the lattice and ber, hence lead to uniform pressure dissemination [20].Pinnata ber material has been effectively created in reinforcing operator of epoxy resin as a useful composite, is quality and in exibility [21].The composite exclusively begins to break up slowly over seven days recently the kenaf strands started to drop out from the composite.This water assimilation capability of the compound composite may have potential applications that require tall water absorption properties [22].The water observation behaviors and high impact property in micro oven kanaf ber test material casing layer and kenaf are called center fabrics.All test comes about uncovered reinforced composite in maximum natural bers substance appears lowest density of kenaf ber density is increased and encloses the maximum substance is (26.68%)[23].The variable factors impacting the ultimate properties of hybrid composite incorporate lattice nature in general ber substance, relative ber volume, ber length, shaping prepare, and ber-matrix interface [24]. the impact substance of oil palm purges natural product or jute composite material.water assimilation in uences of mechanical strength ber composite materials [25].The maximum water absorption is increasing because of the hydro polyvinyl group and natural bers.It is comparatively designated in cellulose composite removals [26].In this paper in uence of nano silicon (IV) oxide particles have been added to the resin concentration to decrease the water absorption action of hybrid kenaf composite materials.A short-term water absorption performance of hemp ber composite depends on mean particle length to bind in nature.The water absorption properties in composite toughened and pure and chemical reaction customized the hemp in three reagents con rmed because of surface modi cation of stu ng in uence absorption [27].Then the distribution of composite which represents and capability of poignant within is a specimen to the coe cient of diffusion process [28].The chemical process of sisal bers is going to analyze various immersion methods that are going to be used [29].Moisture sorption behavior and in ammation of jute epoxy biocomposite ber moistures are observed are increased because of increasing is lled maximum bers [30].The swap resin is more discerning for uoride absorption.Because accessibility of polymeric resins for discerning absorption is very scanty [31].The main role of nano silicon particles with epoxy hybrid composite in reinforced kenaf ber materials is increasing the physical, thermal strength also reduce the impact damage of the properties [32].The purpose of creating fabric is to combine in good mechanical strength of workpieces while eliminating every destitute composite.Injoining of hardened strands and delicate networks is unused good mechanical strength enveloping points of interest of both the ber and matrix materials, this work nd out the highest mechanical strength and low water sorption conduct of epoxy resin silicon added hybrid composite materials.

Materials used
Kenaf materials are ordered and adjacent Agri land of Andrapradesh (India).kenaf bers are prepared annually and the maximum length is 3mm -5mm.The surface-modi cation handle was done by utilizing corrosive hydrolysis prepare in this the molecule and common ber was quickly submerged in arranged uid amino silane arrangement for treatment.The ethanol of weight 95 % and water of weight 5% were taken in measuring and mixed liberally.The speci ed weight rate of amino-silane generally 2 wt % was blended with uid arrangement drop by drop to create a more uniform blend taken after blending.The reinforcements were at that point submerged within the arranged ethanol/Water arrangement ( uid) for a little period and taken out independently.The taken-out forti cations are cleaned awlessly and added ethanol decay overabundance silanization substance of the temperature of 110 o C in a hot oven to remove the moisture.The epoxy resin utilized in uid DGEBA (LY556, Huntsman India Ltd) with a normal molar mass of 185 g/ m, the mass thickness is 1.18 g / cm 3 .The color of this uid is yellowish having two epoxy rings at its closes.The joined epoxy rings open and shapes a linkage when curing prepared takes place.It could be a kind of thermoset gum having an exceptionally brittle structure in its nature.
When blended with ber the tensile strength, exural strength, and toughness are getting increased.Ordinarily, epoxy resin is cured by utilizing an aliphatic or fragrant hardener with sensibility.The pot life of an aliphatic hardener with epoxy resin is around 35-45 min.The nano-silica solution used in this study consider was obtained from Sigma-Aldrich, the USA with a uniform molecule size of 25 nm.For the most part, the molecule density between 0.35 to 0.45 g/cm 3 and having a spherical shape.The nano-silica has high thermal stability, high hardness, and higher chemical and electrical resistance.Additionally, the silica particles have tall antimicrobial substances.

Composite Material Fabrication
The surface-modi ed kenaf ber of quantity 50 vol.% at the combined in changing volume rate of epoxy resin the nano-silicon particle is (0.5, 1.0, and 2.0 vol.%) have mixed.The mixed substances are stirred completely until degassing process.The aliphatic curing hardener of TETA is another advance included with the resin to hardener proportion 10:1 and blended until the hardener is total.The result of viscosity about the colloidal suspension has point poured into an elastic shape is 3 mm thin sheet also wax coated box.A (3 ply box) and 50 vol.% of kenaf mat ber is laid in epoxy resins framework and captured discuss in air bubbles are removed using in a cotton roller.The excess of abundance resins is dropped in physically to arranged the uniform thickness.

Specimen Process
The preparation of silane-treated silicon added kenaf material is dispersed hybrid materials to slash from the molded sheet in (Abrasive jet machines 1515, Kent, USA).This waterjet machine is set up with a working weight of 250-350MPa, rough stream rate is 0.35 Kg/min, garnet dimensions are 80 meshed, and jet nozzle size is 1.1-2 mm are followed for process parameters.Figure 1 as shown in scanning electron microscope structure.

Composition Of Hybrid Composite Materials
The composition of kenaf ber hybrid composite materials is Epoxy resin lled with high immersion level, and Kenaf ber is the maximum size of 3mm and added the 50 vol %, and nano silicon particle is mixed with epoxy in 0-2.0 level of stirred composition.based upon the designation the material strength has been changed the composition of the material as shown in Table 1.The tensile strength, modulus, and elongation of cured kenaf-epoxy and nano-silica half breed epoxy composite are tested with (ASTM) standards D-638 and (ASTM D -3039).The testing machine utilized was a Universal testing machine (UTM) (FIE, India, F150 arrangement) with a 5-ton capacity and cross speed of 2.5 mm/sec.The plain epoxy workpiece was completed based on (ASTM D-638) and reinforced kenaf composite material tested on (ASTM D 3039).Maximum material thickness of 3 mm in all composite workpieces.Figure 2 (b-c) shows the ASTM standard universal testing workpiece.

Flexural Test
The exural test of kenaf ber nano silicon hybrid matrix composites is assessed universal testing machine the maximum load of 40T is connected with (ASTM -D 790).A exural test specimen was conducted on 3 point testing where the bending was placed at the center.Uniform thickness of 3 mm was kept up for all testing workpiece tested and 5 equal specimens were tried to discover the normal values.
The equations 3.1 and exural quality.

Mechanical Properties
Tensile test and exural test values were conducted to silane treatment of silicon nanoparticles added the natural kenaf ber reinforced epoxy hybrid composite plate are explained in Tables 2 and 3.The comparison of mechanical properties has been increased because of surface treatment silicon epoxy hybrid composite materials.The Fig. 5 shows that revolutionize of 53%, 55%, 58% & 62% and 55%, 56%, 58% & 598% were focusing of tensile strength of epoxy, kenaf and silicon (1%,2%,3%) untreated hybrid composite materials respectively.But the improvement of mechanical properties surface treatment reinforced hybrid kenaf ber composite material is 50%, 53%, 56% & 59% and 57%, 58%, 59% & 60% were identi ed for Epoxy, Kenaf and silicon (1%, 2%, 3%).This change capacity of kenaf ber also changes in silicon nanoparticles.A molecule for the most part retains procured moistures and made a high-strength matrix.The silane treated reinforcement surface actuated NH2 particles, The exural test specimen properties are 55%, 56%, 57%, 61% & 63% were focused in composite preparation as shown in Fig. 6 is EK, EKS1, EKS2, and EKS3 respectively.The increasing the exural strength because of silicon -IV oxide mixed materials.The un-modi ed epoxy composites shown ber pull out in matrix materials, whereas the surface-modi ed composite viewed in Fig. 4.4 there's refusal ber pullout and besides the ber parcels appears ne smashed pieces.This process because in un-treated kenaf ber reinforced epoxy composite there's no adhesive between ber and matrix hence it is isolated from the reinforcement stage while in surfacetreated epoxy composite the attachment between ber and matrix is exceptionally maximum form as ne broken shape.

Flexural strength
Figure 8.a,b shows that the Scanning electron microscopic views of the exural test specimen in both untreated and surface-treated order of (EKS3).It is watched that the fractured place appears the wavier layer on the broken line.It shows the arrangement of a more miniaturized scale break.But in surfacetreated EKS3 more shear glasses and stream marks are displayed, which demonstrates progressed ductility within the lattice due to the nearness of grip progressed kenaf ber and nano silicon particles.

Water absorption test
Water absorption testing properties of epoxy material were con rmed in contact angle test methods.The drop load water is constrained on the test example and the images were captured using an optoelectronic system (HOLMERC-HO-IAD-CAM-01).The images have been analyzed for measuring angles with the grounded point reference.The sensor used in this equipment is a CMOS sensor and the video resolution is 2592 X 1944.The lighting procedure utilized here was an LED-based framework Based on the contact point the surface pressure of each example was recognized..The higher the contact angle lesser the water absorption and vice-versa.

Pure epoxy resin and hybrid composites
Table 4 shows that water sorption values unmodi ed and surface-modi ed hybrid composite materials.It is focused on plain resins shows a water immersion percentage of 0.085.It seems like a very minimum value.This very lower water absorption percentage is higher hydrophobic nature of epoxy molecules.In epoxy resin, there are more free OH molecules.These OH molecules are retains very higher hydrophobicity and repel the water uptake.Thus very lower water absorption phenomenon takes place.And silicon added to epoxy, kenaf hybrid composites are predicted the values of 0.81 for EKS3 and surface-treated water absorption values of 0.42 % as shown in Fig. 9. but we need to get the lowest values in treated as processed in 0.39% in EKS2 composition.Table 5 shows that contact angle of untreated and surfacetreated hybrid composites, the contact angle values of pure epoxy resin in 86 o, and surface-modi ed in EKS2 values are shown that 60 o from contact angle sessile drop tester image as shown in Fig. 10.This higher angle explicates the lower surface energy of the solid surface.The experimental results show that comparison of un-treated nano silicon particles in ber epoxy composite the surface treated nano silicon particles in ber epoxy composite predicted the lower water absorption with a high contact angle percentage as shown in Fig. 11 ( a-i).It is distinguished that the untreated composites designation in EKS 3 gives a high level of water sorption percentage of 0.81 with a very lower contact angle of 41 o .And treated hybrid composite kenaf material gives a sessile angle of 60 o in EKS 2 composition.This is often since of exceptionally high surface energy of high moistures delicate the nano silicon particles.But in surface-treated nano silicon particles in ber epoxy composites the water sorption is limited by lower surface energy limits.

Conclusion
Kenaf ber material properties, the quantity of water immersion increases the composite to development from both un-modi ed and surface-modi ed process, but modi ed kenaf ber composite materials have minimum water absorptions as compared to un-modi ed bers.Its actuality has explicit the chemical reaction of hybrid composites..The silanization modi cation was done using acid hydrolysis process used in Ethanol and water of 95/5%.the particulate of hybrid materials temporarily wrapped up in preparation of modulated solutions.The nano silicon IV particles predicted the higher grip with matrix on comparison of untreated and surface-treated kenaf ber materials.The morphological Scanning electron microscope (SEM) images con rmed the improvement and adhesion of ber matrix, with the help of mechanical experimental results in bers.Water absorption test of untreated and surface-treated silicon particle kenaf composite gives 41 o in EKS 3 composite and 60 o is fewer contact angles in EKS 2 shows that minimum water absorption behaviors.

Declarations
Figures

Figure 3 .
(a,b) appears the ASTM exural quality with measurements.3.1.3Water absorption testThe water absorption testing materials were conducted by a submersion test strategy in agreement with ASTM D − 570.The work piece was prepared square shape with measurements of 60 X 60 mm.The test proceeded for 72 hours with open atmospheric air.The formula 3.1 shows the immersion percentage of the water absorption test.Figure 4 (b) shows the water absorption test workpiece as per ASTM standards.Water absorption percentage (%) = [(W1 -W2) / W2] x 100% …………………………(3.1)Where, W1 -Before weight immersion.W2 -After weight immersion.

Figure 7 .
Figure 7.a,b shows the Scanning electron microscopic views of un-treated and surface modi ed kenaf ber reinforcing silicon added epoxy composite materials.

Table 2
Tensile property of un-modi ed and surface-modi ed hybrid composite: