Reinforced Polymer Composites Research Articles

Physico‐mechanical and thermo‐mechanical analysis of zinc borate filled glass fiber reinforced polymer composites

AbstractThe potential benefits of using zinc borate powder as filler material in the production of glass fiber‐reinforced composites were explored in this study. The epoxy matrix was filled with zinc borate powder at 5%, 10%, and 15% by weight, as part of the hand lay‐up approach followed by a compression molding process. Ultrasonication was used to mix the epoxy resin with zinc borate fillers. Both the elemental composition and morphological characteristics were studied using a scanning electron microscope and energy‐dispersive X‐ray analysis. The composite's density, tensile behavior, flexural behavior, impact resistance, and hardness were all measured experimentally. The potential incorporation of zinc borate particles resulted in a modest reduction in the void contents, in addition to enhancing the interfacial bonding in glass fiber‐reinforced composites as also a significant improvement in both the mechanical and thermal properties of the hybrid composites produced. The 10 wt.% zinc borate‐ filled glass fiber‐reinforced composites exhibited a significant rise in both ultimate tensile strength (227 MPa), ultimate compressive strength (239 MPa), and ultimate flexural strength (406 MPa) compared to the unfilled counterpart. The performance of the laminated composites was greatly improved by adding zinc borate powder particles to the matrix.Highlights In the present work glass fiber was reinforced with zinc borate to explore the morphological, mechanical, and thermal properties. Ultrasonication was used to mix the epoxy resin and zinc borate fillers and the composites were manufactured by compression molding process. The addition of zinc borate resulted in an increase in tensile strength, flexural strength, and compressive strength. The thermal stability of the composites was increased by the addition of zinc borate to the glass matrix. The good bonding between the matrix and fiber resulted in improvements in various properties.

Reversible Amidation Chemistry Enables Closed‐Loop Chemical Recycling of Carbon Fiber Reinforced Polymer Composites to Monomers and Fibers

Highly efficient recycling of carbon fiber reinforced polymer composites into monomers and fibers is a formidable challenge. Herein, we present a closed‐loop recycling approach for carbon fiber reinforced polymer composites using reversible amidation chemistry, enabling the complete recovery of intact carbon fibers and pure monomers. The polymer network, synthesized by amidation between a macromonomer linear polyethyleneimine and a bifunctional maleic anhydride cross‐linker, serves as matrices for the construction of composites with exceptional mechanical properties, thermal stability and solvent resistance. The matrices can be fully depolymerized under the acidic condition at ambient temperature, allowing for the effective separation and recovery of both carbon fibers and the two monomers. The reclaimed carbon fibers retain nearly identical mechanical properties to pristine ones, while pure monomers are recycled with high separation yields (> 93%). They can be reused in the manufacture of new composites for multiple cycles, whose mechanical properties recover over 95% of their original properties. This line of research presents a promising approach for the design of high‐performance and sustainable thermoset composites, offering significant environmental and economic benefits.

Effect of zinc oxide surface treatment concentration and nanofiller loading on the flexural properties of unsaturated polyester/kenaf nanocomposites

Due to environmental concerns and budgetary constraints associated with synthetic fibers, natural fibers (NFr) are becoming increasingly popular as reinforcement in polymer composites (PCs) for structural components and construction materials. The surface treatment (ST) method is a well-established technique for enhancing the strength of interfacial bonding between NFr and the polymer matrix (PM). As a result, this research aims to determine the effect of ST with zinc oxide nanoparticles (ZnONPs) on the flexural properties of unsaturated polyester (UPE)/kenaf fiber (KF) nanocomposites. The hand lay-up technique was employed to produce KF-reinforced unsaturated polyester composites (KF/UPE) for this investigation. UPE/KF-ZnONPs composites were made with varying NFr loadings (weight percent), ranging from 10 to 40%. KF was treated with five distinct amounts of ZnONPs (from 1 to 5% weight percent). According to the findings of the investigation, the composite samples incorporating ZnONPs displayed superior optimum flexural properties compared to the untreated KF composite. It was found that 2% ZnONPs was optimal, and ST with ZnONPs could produce robust KF with improved flexural properties.

Flexural strength and flammability of pineapple leaf fiber (PALF)/fire retardants reinforced polymer composites

The use of natural fibers as reinforcement in composite materials, such as pineapple leaf fiber (PALF), has been extensively studied. However, it is important to note that natural fiber-reinforced polymer composites are often associated with high flammability. The aim of this paper is to investigate the mechanical properties and fire retardancy of Pineapple Leaf Fiber (PALF) reinforced polymer composites treated with various flame retardants. The PALF composites were treated with different fire-retardant additives, including ammonium polyphosphate (APP), aluminum hydroxide (ALH), and magnesium hydroxide (MH), at varying ratios (10 wt%, 20 wt%, and 30 wt%). The flexural properties of the PALF composites were assessed using a Universal Testing Machine (UTM) in accordance with ASTM D7264. The flammability testing was conducted following the Underwriters Laboratories 94 (UL-94) using standard ASTM D635 and ASTM D3801. The results of flexural tests indicated that PALF-reinforced polymer composites containing 10% MH as fire retardant exhibited the highest flexural strength (102.96 MPa). Scanning Electron Microscopy (SEM) was employed to analyze the fracture behavior of PALF-reinforced polymer composites with different fire-retardant additives. The SEM analysis revealed various characteristics including fiber pull-out, fiber breakage, inhomogeneous structural distribution (in cases of APP, MH, ALH), presence of undesired bubbles, and fiber–matrix cracking. In terms of fire retardancy, the most promising results were obtained with the addition of 20% and 30% APP. These compositions achieved V-1 and V-0 ratings respectively, in the vertical UL-94 flammability test. Notably, the horizontal test demonstrated that the composites containing 30% APP did not sustain burning and exhibited no burning rate. Similarly, the composite with 20% APP self-extinguished before the first mark without any observable burning rate.

Analysis of dielectric resonator antenna using natural fiber reinforced polymer composites

This work aims to demonstrate the viability of replacing natural fiber reinforced polymer composites for hard ceramics in millimeter-wave dielectric resonator antennas (DRA). The dielectric characteristics of three novel natural fiber reinforced polymer composites were determined using the Lichtenecker logarithmic mixing law. Using two commercial antenna design software packages, CST Studio and ANSYS HFSS, the resulting dielectric characteristics were utilized to study a probe-fed rectangular DRA. Natural fiber-reinforced polymer-based DRAs offer a wider bandwidth than ceramic-based DRAs. Close coupling is obtained by the three natural fiber-reinforced polymer-based antennas and the ceramic DRA. In all cases, the impedance bandwidths observed are the consequence of quasi-TM111 mode radiation. HFSS studies indicate that the resonance frequency of the natural fiber reinforced polymer based DRAs is roughly 75 percent higher than that of the ceramic DRA. CST results indicate that the resonance frequency of the natural fiber polymer-based DRA is approximately 88 percent higher than that of the ceramic DRA. Natural fiber reinforced Polymer-based DRAs have three times the −10 dB impedance bandwidth of ceramic-based DRAs.

Erosion wear assessment of sugarcane fibre reinforced polymer composites for applications of wind turbine blades

This research reports erosion wear characteristics of polyester matrix composite reinforced with short fibres of sugar cane. Erosion tests were conducted using silica sand particles of size (200–500 µm) using a locally designed air jet-type erosion test rig. The sugarcane fibre-reinforced polyester composites (5% wt.) with different fibre lengths (3, 12, 48 mm) were impacted by sand particles at a fixed velocity of 60 m/s, impact angles (30°, 60°, 90°) and erodent weight of (2500,7500) gm. ANOVA approach was used to determine the most significant parameter and their combinations that minimize the erosion rate. Scanning Electron Microscope (SEM) observations were conducted to investigate the erosion mechanisms. Results indicated that the erosion rate is greatly influenced by fibre length as well as the erodent weight. Moreover, at an erodent weight of 2500gm, the behaviour of the material turns from brittle into ductile. At an erodent weight of 7500gm, the erosion rate is inversely proportional to the fibre length.

Low velocity impact performance of natural fibre reinforced polymer composites: a review

Natural fibre-reinforced polymer composites (NFRPC) are versatile and applicable materials for structural applications that require durability and reliability under various forces. However, these composites are susceptible to crack formation when exposed to low-velocity impact (LVI) loads, compromising their functionality and performance. Therefore, it is essential to investigate the influence of LVI on NFRPC and their characterization methods, testing standards, and failure mechanisms. This paper reviews the latest research and development on the characterization, testing, and modelling of NFRPCs under LVI loads. It also explores the impact behaviour of various natural fibres, such as kenaf, bamboo, mallow, buriti, and curaua, and the effect of fibre hybridization and nanofiller incorporation on the LVI response of NFRPCs. The paper evaluates the properties, failure mechanisms, and applications of NFRPCs in relation to LVI resistance. The paper provides useful information for developing advanced composite systems and achieving material efficiency for various structural applications. Finally, it highlights the potential applications and challenges of NFRPC as LVI-resistant materials for advanced composite systems.

Comparative study of carbon and glass fiber reinforced polymer composites for the confinement of concrete columns

This study deals with the comparison of unconfined concrete specimens with carbon fiber reinforced polymer (CFRP) and glass fiber reinforced polymer (GFRP) confined concrete specimens using epoxy as matrix. Initially, CFRP, GFRP and epoxy laminates were prepared for the analysis of various mechanical properties like tensile strength, flexural strength and fracture toughness. From the test results, CFRP and GFRP laminates exhibit better properties than neat epoxy laminate. Axial compressive strength, energy absorption characteristics, failure modes of the confined specimens are analyzed. Comparing with unconfined specimens, it is noticed that the axial load carrying capacity of GFRP confined specimens increased by 23%. While the CFRP confined specimen is compared, a considerable enhancement of 57% was noticed with a confinement effectiveness of 1.57. It is observed that confinement by the FRPs can also increase the fracture energy and ductility index significantly, which can avert the catastrophic failure of the structures.

Investigation on Mechanical Properties of Hybrid Natural Fiber Reinforced Polymer Composite

The use of natural fibers in composite is increasing day by due to eco-friendly nature of the fibres and reuse of waste. Natural fibers can be classified according to their source of origin such as plant fiber, mineral fiber, and animal fiber. In the present article, epoxy was taken as the matrix and wool fiber for reinforcement with flax flax fiber for fabricating the composite using the hand layup technique. The impact of the hybridization of flax and wool fibers on the mechanical properties of natural fiber reinforced polymer composite was investigated. These fibers were blended in varying percentages with fixed fiber content of 5% [(100% flax fiber), (40% wool/60% flax fiber), (50% flax/50% wool fiber), (60% wool fiber/40% flax), (100% wool fiber)] with epoxy resin and sampled as F5, WF23, WF2.5, WF32, and W5 respectively. Tensile strength, flexural strength, and impact strength were investigated through experimentation. All hybrid composites outperformed non-hybrid wool fiber composites in terms of mechanical properties. The wool fiber is poor in mechanical strength which was compensated by high strength of flax fiber.

Application of Natural (Plant) Fibers Particularly Hemp Fiber as Reinforcement in Hybrid Polymer Composites - Part I. Origin of Hemp and Its Coming into Prominence, Cultivation Statistics, and Legal Regulations

ABSTRACT This paper presents a multi-aspect analysis of whether it is feasible and practical to process natural (plant) fibers into fabrics and mats as homogeneous or hybrid reinforcement in polymer composites for use in various industrial sectors. The current, stringent environmental rules of safe recycling and/or disposal of worn or damaged products at the end of their lifetime require new reinforcing materials to be used in polymer composites that need to meet the criteria of energy and material recycling. The paper comparatively analyzed chemical compositions of some selected (plant) natural fibers and compared their physical and chemical properties relative to commonly used synthetic (mineral and carbon) fibers. The world production of respective species of natural fibers has been presented. Industrial hemp was singled out as the possible quality reinforcement to be used in polymer composites in Poland and in Europe. The paper also provided a broader historical perspective of hemp’s importance for mankind over the past 28 thousand years. Hemp’s history and its impact on human development have been discussed. Finally, the paper compiled knowledge on industrial hemp use, agriculture, and processing as well as its current legal status in Poland and abroad.

Mechanical, tribological, and surface morphological studies on the effects of hybrid ilmenite and silicon dioxide fillers on glass fibre reinforced epoxy composites

Recently, researchers have been attempting to enhance the mechanical and tribological characteristics of thermosetting epoxy composites by incorporating inorganic nanoparticles and ensuring their uniform distribution throughout the matrix. This study characterises ball-milled ilmenite (FeTiO3-size of 63 nm) and silicon dioxide (SiO2-size of 67.5 nm) fillers added to epoxy in proportions of 0:0, 2.5:2.5, 5:5, and 7.5:7.5% by weight. A liquid ultrasonic technique is used to blend the fillers with the epoxy, and compression moulding is used to fabricate the composite. Mechanical tests were performed based on ASTM standards. Tensile strength, tensile modulus, flexural strength, flexural modulus and elongations at break(tensile and flexural test) of 5:5 wt % are 30.54%, 12.2%, 32.22%, 28.98%,23.78% and 23.53% higher than neat sample respectively. Shore "D" hardness and Izod's impact strength are 4.65% and 98.93% higher at 5:5 wt % than neat sample respectively. Specific wear rate decreased from 2.6 × 10−11 m3/Nm (neat GFRP: 0 wt % glass fibre reinforced polymer composite) to 0.7 × 10−11 m3/Nm at 5:5 wt % filler. Nanoparticles lowered the coefficient of friction by around 16.66%, 60.42%, and 33.33% at sliding distances of 100 m for 2.5:2.5, 5:5, and 7.5:7.5 wt % respectively with the neat sample. A 5:5 wt percent resulted in 76.68% less wear volume loss than pure GFRP. Field emission scanning electron microscopy (FESEM) analysis revealed element distributions, particle size, pullout of fibers, damaged interfaces, filler dispersion, voids, wear debris, interfacial debonding, and cavities. Thus, this approach enhances GFRP composite's mechanical, tribological, and structural properties.

Free-Standing CNT Film for Interlaminar Toughening: Insight into Infiltration and Thickness Effects.

Carbon fiber reinforced polymer composites have the advantages of being lightweight, having high strength and designability, and having been extensively used. However, the interlaminar toughness and delamination resistance of these composites are relatively poor due to their laminated structure and intrinsic brittleness of resin matrix. In this paper, commercialized free-standing carbon nanotube (CNT) films, drawn from CNT forests, were used to toughen the interlaminar interfaces of the composites. The effects of resin infiltration state and thickness of CNT films on the interlaminar toughening effect were systematically investigated. The results show that the pre-infiltration treatment of CNT films with acetone diluted epoxy resin solution can effectively improve the degree of resin infiltration. Compared with the samples containing untreated CNT film, the Mode I and Mode II interlaminar fracture toughness of the treated samples were significantly improved. The GIC reached a maximum of 1412.42 J/m2 at a CNT film thickness of 5 µm, which was about 61.38% higher than that of the baseline. At a CNT film thickness of 15 µm, the GIIC reached a maximum value of 983.73 J/m2, approximately 67.58% higher than that of the baseline. The corresponding toughening mechanisms were also systematically analyzed.

On the Response to Hygrothermal Ageing of Fully Recyclable Flax and Glass Fibre Reinforced Polymer Composites.

The present work studies the response to hygrothermal ageing of natural fibre composites (NFCs) against synthetic fibre composites when using three different types of polymers as matrices. For ageing, coupons were fully immersed in distilled water at 23, 40, and 60 °C for a total ageing period of 56 days. Flax fibre-reinforced composites, using two recyclable polymer systems: (i) a bio-based recyclable epoxy and (ii) an acrylic-based liquid thermoplastic resin, were tested against conventional glass fibre-reinforced composites employing a synthetic (petroleum-based) epoxy. Different fibre/polymer matrix material combinations were tested to evaluate the effects of hygrothermal ageing degradation on the reinforcement, matrix, and fibre/matrix interface. The hygrothermal ageing response of unaged and aged composite coupons was assessed in terms of flexural and viscoelastic performance, physicochemical properties, and microscopy (SEM-Scanning Electron Microscopy).

RETRACTED: Fabrication and Characterization of Wood Fiber Reinforced Polymer Composites

RETRACTED: Fabrication and Characterization of Wood Fiber Reinforced Polymer Composites

Recent progress in thermal and acoustic properties of natural fiber reinforced polymer composites: Preparation, characterization, and data analysis

AbstractNatural fiber reinforced polymer composites (NFRPCs) have emerged as promising eco‐friendly alternatives over conventional synthetic fiber composites due to their inherent biodegradability, renewability, low environmental impact, and lightweight properties. It has been seen a significant growth in both invention and innovation in the field of NFRPCs. Natural fibers (NFs) reduce the cost of the material by 5%, the weight of the composite by 10%, and the energy required for production by 80%. In terms of thermal, and acoustic properties, NFs can successfully compete with synthetic fibers. As a result, the development of NFRPCs for industrial use has increased significantly in the past decade to meet the growing demands of industrial sectors. To improve the thermal and acoustic properties of NFRPCs, researchers have done a lot of investigation. The aim of the current review is to provide a comprehensive analysis of the existing literature on the thermal and acoustic properties of natural fiber reinforced polymer composites. Thermal properties such as thermal conductivity, TGA, DSC, DMA, and acoustic properties of natural fiber reinforced composites with several parameters, such as different fiber types, different matrix types, fiber weight ratio, fiber to matrix ratio, chemical treatment of fiber have been summarized and analyzed very concisely. This review also emphasizes a summary of different natural fibers, their chemical compositions, composite preparation, characterizations, and future research directions. This article enables the readers, researchers, and manufacturers to realize several opportunities about the latest developments in NFRPCs for the application of thermal and acoustic purposes.Highlights Natural fibers can successfully compete with synthetic fibers, in terms of thermal and acoustic properties. Thermal properties of natural fiber reinforced composites including thermal conductivity, TGA, DSC, and DMA are summarized. Acoustic properties of natural fiber reinforced polymer composites are discussed. Composite materials made of treated fibers result better thermal stability than untreated fiber composites. Sound absorption coefficient generally increases as fiber content increases.

Fabrication and Characterization of Wood Fiber Reinforced Polymer Composites

Fabrication and Characterization of Wood Fiber Reinforced Polymer Composites

Study of frequency dependence properties of CCTO-BT/polymer composites

In the current study, the calcium copper titanate (CCTO)/polymer, barium titanate (BT)/polymer, and CCTO-BT/polymer composites with variable volume fractions of CCTO and BT are fabricated using hand lay-up and compression molding processes. The composites are characterized for the frequency dependence on dielectric properties, conductivity, impedance spectroscopy, and electrical modulus. X-ray diffraction (XRD) patterns of CCTO-BT/polymer composite samples confirmed the presence of both CCTO and BT ceramic samples separately. The dielectric properties of hybrid CCTO-BT/polymer composites with 10 vol% CCTO 10 vol% BT, 12 vol% CCTO 8 vol% BT, and 8 vol% CCTO 12 vol% BT was found relatively better than those of the single ceramic filler reinforced polymer composites. AC conductivity analysis shows a significant improvement in the results of hybrid filler-filled CCTO-BT/polymer composites in comparison with single filler-filled polymer composites. Thus, impedance analysis confirms higher insulating properties for 8 vol% CCTO 12 vol% BT and 12 vol% CCTO 8 vol% BT hybrid CCTO-BT/polymer composites with respect to the single and other hybrid ceramic polymer composites. The analysis suggests the hybrid CCTO-BT/polymer composites to be adopted as a possible dielectric material for energy storage devices and other electronic applications.

Effect of alkali treatment on properties of Palmyra palm tree primary flower leaf stalk fiber–reinforced polymer composites

Effect of alkali treatment on properties of Palmyra palm tree primary flower leaf stalk fiber–reinforced polymer composites

Effect of various factors and hygrothermal ageing environment on the low velocity impact response of fibre reinforced polymer composites- a comprehensive review

Effect of various factors and hygrothermal ageing environment on the low velocity impact response of fibre reinforced polymer composites- a comprehensive review

Nano-gelcoat application of glass fiber reinforced polymer composites for marine application: Structural, mechanical, and thermal analysis

To address the critical issue of environmental sustainability, the application of nano-gelcoat has emerged as a promising approach to extend the service life and enhance the durability of glass fiber-reinforced polymer composites (GFRPs), thereby protecting the marine environment. Despite the extensive use of GFRPs in marine structures, their performance is significantly influenced by marine environmental factors. However, despite its potential, there is a lack of research on the experimental application of nano-gelcoat. To fully understand the underlying mechanisms and optimize the performance of nano-gelcoat application, more experimental investigations are required. In the present study, the hydrothermal aging of nano-gelcoat-coated glass fiber-reinforced polymer composites was investigated. Nano TiO2 and nanoclay were used to enhance the performance of gelcoat. A three-month hydrothermal aging experiment was carried out in artificial seawater heated to 80 °C. Mechanical and water absorption properties of GFRPs and thermal, morphological and FTIR (Fourier transform infrared spectroscopy) properties of nano-gelcoat were investigated. An ANOVA analysis was performed to establish if the experimental results were statistically significant. The long-term aging tests showed that the addition of nano-TiO2 improved water resistance and maintained the mechanical properties of the composite. It also improved the melting point.