Fiber Reinforced Vinyl Ester Composites Research Articles

Influence of silane functionalized heat treated biosilica on mechanical, wear, and dynamic load–bearing properties of nettle fibre–reinforced vinyl ester composites

Influence of silane functionalized heat treated biosilica on mechanical, wear, and dynamic load–bearing properties of nettle fibre–reinforced vinyl ester composites

Influence of betel nut fiber hybridization on properties of novel aloevera fiber-reinforced vinyl ester composites

Abstract This work presents the influence of betel nut fiber hybridization on the properties (mechanical, thermal, wear, and water absorption) of novel aloevera fiber-reinforced vinyl ester composites. In this research, we fabricated the composites by changing the wt.% of aloevera fiber and betel nut fiber through the hand layup method using the compression molding technique. From the results, it has been observed that increases in wt.% of betel nut fiber increased the mechanical properties, thermal properties, wear resistance, and water resistance of the composites. The composite with the designation S1 shows the lowest hardness, tensile, flexural, impact, and shear strengths of 49.58, 26.59 MPa, 52.53 MPa, 4.12 J, and 101.26 MPa, respectively. Meanwhile, the composite with the designation S5 shows the highest hardness, tensile, flexural, impact, and shear strengths of 71.29, 62.61 MPa, 78.24 MPa, 9.57 J, and 139.52 MPa, respectively. Further, higher wear resistance and water resistance were obtained by the S5 specimen. SEM analysis shows the good strength of betel nut fiber and enhances the tensile strength of the composites.

Mechanical, thermal, chemical, and physical properties of sponge gourd outer skin fiber-reinforced vinyl ester composites

Mechanical, thermal, chemical, and physical properties of sponge gourd outer skin fiber-reinforced vinyl ester composites

Mechanical and tribological behavior of pineapple leaf and kenaf fiber reinforced vinyl ester hybrid composites

The modern world demands the implementation of natural fiber-based polymer composites over synthetic fiber composites due to their eco-friendly nature, abundant availability, competing strength, economical favorability, and lightweight quality. In this present investigation, varied combinations of hybrid pineapple leaf fiber (PALF) and kenaf fiber-reinforced vinyl ester composites were fabricated by compression molding technique. The physical properties, mechanical properties, and tribological behavior were experimentally analyzed and reported. The physical properties, such as theoretical density, experimental density, and porosity percentage are evaluated and studied. Statistical mechanical tests such as tensile, flexural, compression, microhardness, and impact study are also evaluated possibly. Tribological behavior was simply studied by pin-on-disc tribometer apparatus under dry sliding conditions, and its specific wear rate and coefficient of friction were determined and analyzed. The morphological features of the tensile fractured samples and worn surfaces of the wear-tested specimen were analyzed by using a scanning electron microscope and its effects were investigated. From the results reported, it was claimed that the 20PALF/20KF/60VE sample was getting higher mechanical properties of 51% increased tensile strength, 55% flexural strength, 41.5% compression strength, 52% impact results, and 52% increased harness value compared to the neat resin sample. Overall results state that the hybridized combinations of PALF and kenaf fibers reinforced composites attained good mechanical and tribological properties and appear promising for printed circuit board and electrical switchboard applications.

Effect of Fiber Length and Loading on the Mechanical Characterization of Cyperus Pangorei Fiber Reinforced Vinyl Ester Composites

Polymer composites fabricated using plant fibers have become a dominant role in number of industries due to the outstanding results of their physical and mechanical characteristics when compared to traditional materials. The current study aims to develop lightweight and affordable composite materials using Cyperus pangorei fiber (CPF) and a vinyl ester (VE) resin matrix. Comparing the characteristics of composite materials created with different fiber lengths (3 to 11 mm) and contents (10 to 50% weight). The composite with 7mm fiber length and 40% of fiber content demonstrated the highest level of stability among the various fiber weight and lengths percentages tested. A composite system's fiber contents have a significant impact on its overall performance. The bonding of fibers and matrix of the specimens were good, according to SEM analysis. As a result, the current study suggests that the optimal CPF-reinforced VE composites would be a capable substitute to traditional materials for value-added engineering products.

Mechanical characterization of banana-nylon fibre reinforced Vinyl ester composites

ABSTRACT Hand lay-up was used to create banana and nylon Fibre-reinforced vinyl ester (VE) composites with random orientation of the short fibre ratio (banana:nylon = 1:1). To make it environmentally conscious, natural fibre (banana) was added in synthetic fibre (nylon). After fabrication, different mechanical testing was conducted. Tensile strength improves by 47% at 10 wt. % fibre loading and 13% at 20 wt.% fibre loading. Flexural strength improved by up to 213% at 15 wt. % fibre loading. At 20 wt. % fibre loading, the mean hardness number reaches its maximum. The mean impact energy is highest at 15 wt. % fibre loading. Furthermore, the highest water absorption is 2.3% with a fibre loading of 20 wt.%. After 15 wt.% fibre loading, which is suggested for optimal performance, the manufactured composites exhibit a declining trend in tensile, flexural, and impact capabilities. As a result, scanning electron micrographs were collected at 20 wt.% fibre loading to investigate the type of fibre-matrix bonding, voids, fibre agglomeration, and fibre pullouts phenomena. Fourier Transform Infrared spectroscopy was also explored to show a decline in hemicelluloses content. As-fabricated composites have several technological uses, including leisure and sports products, maritime sectors, and airplanes.

Effects of vacuum infusion configuration on homogeneity of glass fiber reinforced polymer composites for automotive components

In this study, the effects of vacuum infusion configuration on the homogeneities of glass fiber reinforced vinyl ester composites have been evaluated. Three different sizes of samples (100x100, 500x500, and 1000x1000 mm) were fabricated. Three different configurations were used to fabricate the samples. The first two configurations had one inlet, while the third configuration had two inlets for resin infusion. Thickness variations and hardness (Shore D) measurements were performed to determine the homogeneities of the samples. The results revealed that, for small size samples, the configurations have no obvious effect on the homogeneity of the samples, both in terms of thickness variations and hardness values. However, for larger samples, the configuration where the resin is introduced into the preform in the center of the component showed better homogeneity than other configurations. Even a better distribution is assessed with the introduction of the resin in the center of the sample, although this configuration also resulted in thickness swellings in the central areas of the sample. The thickness swellings were observed around the inlet areas for all configurations. The study shows that the resin flow in the center of the component is preferable but thickness swelling must be considered when dimensional tolerances are critical.

Hydrothermal Ageing of Glass Fibre Reinforced Vinyl Ester Composites: A Review.

The use of glass fibre-reinforced polymer (GFRP) composites in load-carrying constructions has significantly increased over the last few decades. Such GFRP composite structures may undergo significant changes in performance as a consequence of long-term environmental exposure. Vinyl ester (VE) resins are a class of thermosetting polymers increasingly being used in such structural composites. This increasing use of VE-based GFRPs in such applications has led to an increasing need to better understand the consequences of long-term environmental exposure on their performance. The reliable validation of the environmental durability of new VE-based GFRPs can be a time- and resource-consuming process involving costly testing programs. Accelerated hydrothermal ageing is often used in these investigations. This paper reviews the relevant literature on the hydrothermal ageing of vinyl ester-based GFRP with special attention to the fundamental background of moisture-induced ageing of GFRP, the important role of voids, and the fibre-matrix interface, on composite mechanical performance.

Mechanical Characterization of Hybrid Polymer Composite for Marine Application

An investigative work was conducted to examine the tensile, flexural and impact strength of carbon fiber reinforced vinyl ester composites filled with different proportions (0, 0.5, 1, 1.5 and 2) of graphitic carbon nitride (g-C3N4) and silicon nitride (Si3N4) filler. Composites were fabricated by hand layup method. Results showed an increase in tensile strength of g-C3N4 and Si3N4 particles content by 1% and beyond which the strength decreased. With the addition of 1wt% of g-C3N4 and Si3N4 in carbon fiber reinforced vinyl ester composites, the flexural strength increased to 16% and the tensile strength increased by 10%. The eroded surface of specimen was observed under scanning electron microscope and the results are reported. Incorporation of nano fillers in hybrid polymer composite will enhance the mechanical properties. Hence hybrid C-V extensively used in marine applications.

Effects of fiber content and its chemical treatment on the mechanical properties of screw pine fiber reinforced vinyl ester composite

Natural fiber-reinforced polymer composites have several advantages over traditional composites. The chemical modification of natural fibers helps to develop polymer composites with better mechanical properties. In the present work, mechanical properties such as tensile, flexural, and impact strength of chopped Screw pine fiber reinforced vinyl ester composites have been evaluated under-treated conditions based on the volume fractions of Screw pine fibers. The fibers have been treated with 5% of NaOH solution for 1 h at room temperature. The hand lay-up method has been used to prepare composite plates at room temperature. The results revealed that mechanical properties of composites increased with the increase of the fiber content up to 35.57 vol% at both the untreated and treated conditions and then dropped. However, the modulus values have been increased continuously from the fiber content of 8.43 to 45.3 vol%. It was identified that the critical or optimum fiber content for better mechanical properties is 35.57 vol% for both the untreated and treated conditions. The percentage of improvement at every combination was obtained by comparing the composites prepared with the untreated and treated fibers. The fractured surface of the treated fiber composites was examined by scanning electron microscopy. Moreover, the tensile properties are predicted using the Hirsch and Modified Bowyer and Bader model and compared with experimental values. The predicted results revealed that the Modified Bowyer and Bader model shows better conformity.

Mechanical Behaviour and Thermal Properties of Pine Apple Leaf Fiber Reinforced Vinyl Ester Composites

Despite its mechanical and environmental properties, pineapple leaf fibers (PALF) are used as a home threading material in India. In addition, the effects of abrasive combing and pretreatment techniques on fiber and composite characteristics were examined in this work. Using PALF vascular bundles separated from different regions of the leaves did not affect the mechanical aspects of pineapple leaf fiber-vinyl ester composites. PALF fibers performed equally in strengthening composite flexural properties under static loading, regardless of diameter or location, with a much lower weight percentage and combined pressure. Tests at higher speeds revealed that the PALF-vinyl ester composite was more robust with more delicate bundles. Reinforcing composites that do not require a high degree of hardness can benefit from the cleaner, more delicate bundles produced by abrasive combing.

Artificial Neural Network Modeling of Abrasion Loss and Surface Roughness of Crab Carapace Impregnated Coir Vinyl Ester Composites

Roughness plays an important role in determining how an object would be related with its environment. In tribology, rough surfaces easily obtain wear more quickly and have higher friction coefficients than smooth surfaces. Roughness is often a good analyzer of the performance of a mechanical component. This investigation is aimed to study the abrasion loss and surface roughness behaviors in crab carapace-filled coir fiber reinforced vinyl ester composites. The development of filler-impregnated fiber-polymer composites in recent years necessitated the evaluation and prediction of tribological behaviors in fiber reinforced composites. The composite fabrication was planned by varying the three fabrication parameters with three levels such as fiber length (10 mm, 30 mm, and 50 mm), fiber diameter (0.1 mm, 0.18 mm, and 0.25 mm), and content of crab carapace fillers (0%, 2%, and 4%) as per Design of Experiments (DOEs) in this current investigation. Low velocity integrated wear loss tests on composite samples were carried out, and also the average surface roughness is measured in the fabricated composites. Nonlinear regression equations were developed to study the correlation between tribological behaviors and fabrication parameters. The interaction effect of fabrication parameters was studied using ANOVA two-tail test and validated using response surface plots. In order to forecast abrasion loss and surface roughness behaviors, artificial neural network (ANN) models were constructed, and it was discovered that the produced ANN models effectively predicted the abrasion loss as well as surface roughness behavior within the given ranges.

Studies on mechanical and fracture properties of basalt/E‐glass fiber reinforced vinyl ester hybrid composites

AbstractIn this study, a comparative analysis of basalt, E‐glass and hybrid fiber reinforced vinyl ester composites was carried out. Composites were fabricated using vacuum infusion process with 0°/90° and ±45° as fiber orientation angles. The influence of volume fraction on mechanical behaviors and surface morphology of impact fractured composites were analyzed. The glass and basalt fibers oriented at 0° have shown higher load bearing capability, whereas the fibers oriented at 45° angle have shown higher plastic deformation. Hybridized composite having silane treated glass fibers has shown enhanced mechanical properties including tensile strength, bending strength, toughness, and elongation at break due to good bonding between fibers and polymer matrix. The tough and flexible interface between fiber and matrix dissipates more energy through stress transfer from matrix to fiber, allowing increased resistance to shearing. The impact test of BGS‐0.2 hybrid composite showed 103% and 108% of strength improvement compared to basalt (B‐0) and glass fiber (G‐0) reinforced laminates, respectively. However, the fiber orientation at 45 degree showed reduced the strength and modulus with high elongation. The fractography micrographs of hybrid composites have shown the effectiveness of basalt and glass fiber orientation in the composites and bonding between fiber and matrix indicating flexible interphase between the fiber and matrix during impact loading. The composites added with silane have shown marginal increase in water uptake due to presence of polar functional groups in the coupling agent.

Utilization of waste dolomite dust in carbon fiber reinforced vinylester composites

The present study was designed to explore the applicability of dolomite dust (a waste from a dolomite quarry) as filler in polymer composites. Therefore, fixed carbon fiber reinforced vinyl ester composites with varying dolomite dust proportions (0, 5, 10 and 15 wt.%) are manufactured and subsequently evaluated for physicomechanical and sliding wear properties. Experimental results indicate that density, void content, impact energy, hardness, tensile modulus, and flexural modulus increase with dolomite content increase. On the other hand, a continuous decrease in tensile and flexural strength was observed with increased dolomite dust content. The sliding wear tests were performed using L16 orthogonal design, considering four parameters: dolomite dust, sliding distance, applied load, and sliding velocity according to the Taguchi method. It was found that dolomite dust was the most noteworthy parameter of wear rate, followed by applied load and sliding distance.

Effect of the double bond content of sizing agents on the mechanical properties of carbon fibre reinforced vinyl ester composites

Unsaturated polyester sizing agents with various double bond contents have a significant influence on the interface between carbon fibers (CF) and vinyl ester resins (VER). This paper aims to study the effect of the double bond content of sizing agents on the surface properties of CF and thermo mechanical properties of the sized CF/VER composites. We synthesized five types of self-emulsifying cationic sizing agents with various double bond contents and characterized the samples by FTIR, dynamic light scattering (DLS), cryo-scanning electron microscopy (Cryo-SEM) and thermal gravimetric analysis (TGA). The double bond content of the sizing agents on the cross-linking extent of the CF surface were investigated on factors such as the wettability of VER, the interlaminar shear strength (ILSS) and flexural strength and modulus of CF/VER composites. It was identified that the distribution of the sizing agent emulsions had a mono-dispersion of around 50 nm and were thermally stable below 300 °C. Additionally, it was identified that the double bond content of the sizing agents enhanced the grafting reactions and cross-linking extent between the sizing agent and CF surface. The CF had the best wettability for vinyl ester resin when the double bond content was 10% in the sizing agent. In addition, the ILSS, the flexural strength and the modulus reached maxima.

Study of Mechanical Properties of Roselle Fiber Reinforced Vinyl Ester Biocomposite Based on the length and content of Fiber

Mechanical properties of Roselle fiber reinforced vinyl ester biocomposite were studied based on the fiber content and length in the present communication. Usually, natural fiber reinforced polymer composites depend on some aspects such as fiber content, fiber length and orientation, the fiber-matrix adhesion. Composite plates were prepared by a simple hand lay-up technique for two different fiber lengths (3 and 13 mm) and five different fiber content (10, 20, 30, 40 and 50 wt%). Composite specimens were tested according to ASTM standards and their results were recorded. Experimental results showed that mechanical properties such as tensile, flexural and impact, increases with increase of fiber content up to 40 wt% after which it is decreases at both the fiber length. However, modulus values were increased linearly with fiber content of 10 to 50 wt%. Composites with the fiber length of 13 mm show the high level of mechanical properties compared to composites with the fiber length of 3 mm at all combinations of fiber contents. It is observed that the optimal fiber content is 40 wt%, which can be used to obtain the maximum property level in the Roselle fiber reinforced vinyl ester composites

High speed impact performance of basalt fiber reinforced vinylester composites at room and low temperatures

This paper presents the results of a wide research project aiming to determine the performance of plain basalt and hybrid glass/basalt and carbon/basalt reinforced vinylester matrix composites under high-speed impact. Experimental tests are carried out by shooting steel balls in the range of 200–800 m/s in a compressed-gas gun. Results are depicted as curves of residual velocity vs. impact velocity from which the ballistic limit (V50) is derived for all material configurations and different environmental conditions including temperature and water saturation. Experimental results are used to validate a new analytical model previously developed by the authors to model the projectile impact on a plate. A good agreement is observed between experimental and analytical predicted results.

Influence of Water Absorption on the Low Velocity Falling Weight Impact Damage Behaviour of Flax/Glass Reinforced Vinyl Ester Hybrid Composites.

Due to rigorous new environmental legislations, automotive, marine, aerospace, and construction sectors have redirected their focus into using more recyclable, sustainable, and environmentally friendly lightweight materials driven by strengthening resource efficiency drive. In this study, the influence of moisture absorption on flax and flax/glass hybrid laminates is presented with the aim to investigating their low velocity impact behaviour. Three different types of composite laminates namely, flax fibre reinforced vinyl ester, flax fibre hybridised glass fibre and glass fibre reinforced vinyl ester composites were fabricated using resin infusion technique. The moisture immersion tests were undertaken by immersing the different specimens in sea water bath at room temperature and 70 °C at different time durations. The low velocity falling weight impact testing was performed at 25 Joules of incident energy level and impact damage behaviour was evaluated at both ageing conditions using scanning electron microscopy (SEM) and X-ray microcomputed tomography (micro CT). The percentage of moisture uptake was decreased for flax vinyl ester specimens with glass fibre hybridisation. The maximum percentage of weight gain for flax fibre, flax/glass hybrid and glass fibre reinforced composites immersed at room temperature for 696 h is recorded at 3.97%, 1.93%, and 0.431%, respectively. The hybrid composite exhibited higher load and energy when compared flax/vinyl ester composite without hybridisation, indicating the hybrid system as a valid strategy towards achieving improved structural performance of natural fibre composites. The moisture absorption behaviour of these composites at room was observed to follow Fickian behaviour.

Enhancement of mechanical properties of glass fiber reinforced vinyl ester composites by embedding multi-walled carbon nanotubes through solution processing technique

This experimental study emphasizes the effect of the incorporation of multi-walled carbon nanotubes (MWCNTs) in conventional fiber reinforced-polymer composites on mechanical and thermal performance. Hand layup method was adopted for fabricating glass fiber reinforced vinyl ester (GVE), and 0.1 wt% MWCNTs filled GVE (MWCNT-GVE) composites. Bidirectional woven glass fiber (GF) and vinyl ester (VE) resin were used as reinforcement and matrix, respectively. The MWCNTs-VE suspension was prepared by solution processing technique. Mechanical properties were found to be affected by embedding MWCNTs in the neat GVE composite. MWCNT-GVE composite showed about a 7.37% increment in flexural strength and about 11.64% increment in tensile strength over neat GVE composite. Through differential scanning calorimetry (DSC), glass transition temperature (Tg), and the effect of MWCNTs on thermal properties of experimental composites were analyzed. A decrease in Tg value was observed after incorporating MWCNTs in GVE composite. Post failure, analysis was done by scanning electron microscope (SEM).

Enhancing the Static and Dynamic Mechanical Behaviours of Vinyl Ester Matrix using Surface Modified Luffa Fibers

This study focuses on enhancing the static and dynamic mechanical behaviours of vinyl ester matrix using surface modified Luffa fibers. The density of Luffa fiber, which belongs to Cucurbitaceae family, is 1.2 g/cc. The Luffa (Ridge gourd) vegetable was dried in sun-light and the required fiber layers were then obtained by using manual extraction process. The fiber layers were then treated with alkali (5% of NaOH) solution at ambient temperature (28o C) for 24 h. From the SEM images, it can be inferred that the chemical treatment did not degrade the fiber surface and retained its reinforcing nature. The Luffa fiber reinforced vinyl ester composites were developed by hand layup technique by varying the number of fiber layers (1, 2 and 3). The morphological and mechanical behaviours of the developed composites were analyzed as per ASTM standards and compared with pure resin. The static and dynamic mechanical properties of vinyl ester composites exhibited significant improvement with fiber surface treatment and increase in number of fiber layers. Among the different composites tested, the composite specimen with three layers of alkali treated fiber exhibited the highest tensile strength (18.88 MPa) compared to untreated fibers (16.83 MPa). The improvement in properties of Luffa fiber reinforced composites can be attributed to the removal of lignin and waxy substances from the fiber by chemical treatment, which was confirmed by SEM. The obtained results indicate that composites reinforced with three layers of surface modified Luffa fibers showed overall improvement in static and dynamic mechanical behaviours.