Fiber Polymer Composites Research Articles

Biomimetic flow field flame retardant modification of sisal fiber and its polypropylene composites

The lumen of sisal fiber provides a good space for loading flame retardants and constructing a three-dimensional flame-retardant network, effectively improving the flame retardancy of their polymer composites. In this study, we combined water/nutrient transport mechanism of plant fiber with layer-by-layer self-assembly technology, innovated a biomimetic flow field flame retardant modification method and successfully deposited ammonium polyphosphate (APP) and polyethyleneimine (PEI) into sisal fiber lumen. After 20 cycles modification, the flame retardants in fiber increased to 18.36wt%. Its TG residue achieved to 43.23% from 17.35% (unmodified) and its limited oxygen index (LOI) value achieved to 39.1% from 20.7% (unmodified). Compared to directly immersing fiber in APP/PEI solution, this method mitigated the blockage of flame retardants at lumen entrance and realized a uniformly deposition in lumen interior. When blending this modified fiber with polypropylene (PP) at 30wt% (the flame retardant content is only about 4.65wt%), the composite TG residue increased from 3.10% (unmodified) to 15.77%, and its LOI value increased from 19.4% (unmodified) to 23.2%. This composites also has better flame retardancy than APP/PEI directly dispersed in PP matrix (TG residues 11.10%, LOI value 21.1%). For sisal fiber polymer composites, employing fiber lumen as flame retardant carrier could improve its flame retardancy efficiently. The carried flame retardants inhibit the combustion of flammable sisal fiber, and the constructed flame-retardant network restrict PP matrix combustion.

An intrinsic investigation of surface treated Kevlar intraply patch-repaired glass fiber polymer composites

An intrinsic investigation of surface treated Kevlar intraply patch-repaired glass fiber polymer composites

Optimization of Fiber-Polymer Ratios for Enhanced Mechanical Properties in 3D-Printed Composites

The ratio of fiber to polymer is significant for improving the mechanical properties of fibrous polymers that are used for 3D printers’ applications in aerospace, automobile and Biomedical industries. This research on the behavior of fiber reinforced polymer composite material compares the impact of different fiber content on tensile strength, flexural strength, and impact resistance of 3D printed fiber reinforced polymer composites. From a range of fiber contents of 10%, 20%, and 30%, efficiency rises progressively with increasing fiber ratios, with the composite’s maximum tensile strength and flexural strength reached 60 and 55 MPa, respectively at the 30% fiber ratio. Nevertheless, if a structure exceeds the maximum of averaged values, one can meet more severe problems that have been described as brittleness and limited versatility in this study, which means that an optimal use of composites should imply a subtle balance between these parameters. Fiber-matrix adhesion is also a significant factor discussed in the study, which is a key parameter that defines the ultimate strength and life of the developed composites. These results do not only contribute to the knowledge of using 3D-printed composite materials but also provides benefits for proposing specific ideas in industries which attempt to introduce lightweight and high strength parts in their production lines. Some areas for further investigation are the effect of using other fiber orientation and the use of the hybrid fiber-polymer composites to achieve better mechanical properties and overcome problems arising from high fiber content. More specifically, this work helps to enrich the existing knowledge on the nutritional values of fibers and polymers with the aim of achieving optimal fiber-polymer ratios for enhancing the technique of three-dimensional printed composites

Micro-void nucleation at fiber-tips within the microstructure of additively manufactured polymer composites bead

The presence of voids within the microstructure of short carbon fiber polymer composites produced by additive manufacturing (AM) technology are known to alter the expected material behavior that impair part performance. Previous research efforts aimed at understanding the formation mechanisms of these micro-voids during the polymer extrusion/deposition process have not kept up with the advancement of this AM technology. The present study investigates the phenomenon of micro-void nucleation at the fiber/matrix interface, especially those that form at fiber tips, by characterizing the microstructural configuration of a 13 % carbon fiber filled ABS polymer composite print bead specimen using 3D X-ray micro computed tomography image acquisition and analysis. The results reveal a high level of micro-voids segregation at the ends of fibers that are relatively larger in size and less spherical as compared to micro-voids isolated within the ABS matrix. Additionally, by simulating the hydrostatic flow-field pressure distribution surrounding a single rigid ellipsoidal fibre in colloidal suspension using Jeffery’s model equations, we show that the pressure drops to a critical value at the fibre tips where the micro-voids nucleation is experimentally observed to occur. The study helps to improve our understanding of the potential mechanisms that may be responsible for micro-void development within beads printed with extrusion/deposition AM.

Exploring synergies between GnP and fiber orientation in enhancing mechanical, thermomechanical, and shape memory properties of carbon fiber polymer composites

Abstract This research investigates the mechanical, thermomechanical, and shape memory properties across 12 configurations of shape memory hybrid composites, varying in carbon fiber orientation: uni-directional (UD), bi-directional-Twill (BDT), and bi-directional-Plain (BDP), and graphene nanoplatelets (GnP) weight percentages of 0.4%, 0.6%, and 0.8% elucidate the synergistic effects of fiber architecture and nanomaterial reinforcement. The fabrication process involves initially preparing GnP-modified epoxy nanocomposites through ultrasonication followed by hand layup techniques to fabricate three-phase shape memory hybrid composites. Optimal tensile performance is observed in GnP-modified UD composites at a 0.6 wt% concentration, achieving a tensile strength of 728.32 MPa and a modulus of 71.29 GPa. Furthermore, enhancements in thermomechanical and shape memory properties are noted in GnP-modified BDT composites and are further improved in GnP-modified BDP composites configurations. These improvements are attributed to enhanced interfacial bonding between the polymer and fiber, with the maximum effect observed at the 0.6 wt% BDP composite, validated by morphological analysis using field emission scanning electron microscopy FESEM. The study demonstrates that despite polymer modification, all configurations maintain high shape recovery ratios, particularly notable at 97.54% for 0.6 wt% GnP modified BDP composite, exceeding 90% across all configurations, indicating robust performance in shape memory capabilities.

Characterization and modelling of the microstructural and mechanical properties of additively manufactured continuous fiber polymer composites

The additive manufacturing of continuous fiber reinforced polymer composites is a technology showing great potential for the production of end-use functional and structural components. The reasons for its still limited use are primarily related to an insufficient knowledge of the mechanical behavior of these composites, especially when considering the features that distinguish the printed components from conventional composite parts. Among these peculiar features, their bead-based architecture has been experimentally and analytically investigated in this study. Following an analysis of the process-morphology correlation, carbon fiber (CF)/polyamide 12 (PA12) specimens were tested to characterize the in-plane quasi-static material properties. Then, a modelling framework has been proposed for assessing the composite elastic properties and average bead stresses. This framework holds the potential to scale up to a structural level, accommodating various fiber trajectories.

Shape parameter of Weibull size statistics is a potential indicator of filler geometry in SiO2 reinforced polymer composites

In a previous study [Physica A, 625 (2023), 129026], a relationship between the filler size distribution and the filler geometry of SiO2 particle reinforced polymer composites has been reported. It has been experimentally demonstrated that the size of hollow and solid SiO2 particles disperse in polymer matrix follows Weibull statistics with shape parameter at 2 and 3, respectively. This mechanism has not yet been verified in the one-dimensional (1D) case. In this paper, we study the length distribution of glass fibers in polymer composites. Our results show that the previous theory still holds for the 1D case. Thus, shape parameter of Weibull size statistics could be a potential indicator of filler geometry in SiO2 reinforced polymer composites. This interesting mechanism can be explained by the scaling nature behind the Weibull statistics. Our study has thus shed new light on the evolution of filler geometry during the fabrication process of polymer composites, and should be useful for the related fields.

The Influence of the Amount of Technological Waste on the Performance Properties of Fibrous Polymer Composites

The objective of the experimental analysis was to assess the impact of the reuse of technological waste (recyclate) on the selected performance properties of the fibrous polymer composite used to produce components for the automotive industry by injection molding technology. Polyphthalamide (PPA), which belongs to a group of high-tech polymers, was chosen as the analyzed material. In accordance with the set goals, the rheological, mechanical, and structural properties of the material were evaluated using ANOVA analysis in the experimental part of the work, depending on the mass ratio of the recycled material added to the virgin material. The influence of the proportion of recycled material on the lifetime of moldings by the method of their exposure at an elevated temperature for a defined time was also assessed. During the research, it was found that at a concentration of up to 40 wt. % of recyclate, its mechanical properties do not change significantly. At a concentration of 50 wt. %, there is a rapid decrease in mechanical properties. In the long term, it can also be said that the addition of recyclate significantly affects the service life of the components. No significant changes in morphology were observed during the analysis of structural properties.

In‐situ fabrication of poly‐l‐lactide & its application as a glass fiber polymer composites using resin transfer molding

In‐situ fabrication of poly‐l‐lactide & its application as a glass fiber polymer composites using resin transfer molding

Upcycling end-of-life carbon fiber in high-performance CFRP composites by the material extrusion additive manufacturing process

Each year, a significant amount of waste is produced from carbon fiber polymer composites at the end of its lifecycle due to extensive use across various applications. Utilizing regenerative carbon fiber as a feedstock material offers a promising and sustainable approach to additive manufacturing based on materials. This study proposes the additive manufacturing of recycled carbon fiber with a polyamide-12 polymer composite. Filaments of recycled carbon fiber-reinforced polyamide-12 (rCF-PA12) with different recycled carbon fiber contents (0%, 10%, and 15% by weight) in the polyamide-12 matrix are developed. These filaments are utilized for 3D printing of specimens by using various infill density parameters (80% and 100%) on a fused deposition modeling 3D printer. The study examined how the fiber content and infill densities influenced the flexural performance of the printed specimens. Notably, the part containing 15 wt% recycled carbon fiber (rCF) composites showed a significant improvement in flexural performance due to enhanced interface bonding and effective fiber alignment. The results indicated that reinforcing the printed part with 10% and 15 wt% recycled carbon fiber (rCF) improved the flexural properties by 49.86% and 91.75%, respectively, compared to the unreinforced printed part under the same infill density and printing parameters. The investigation demonstrates that the additive manufacturing-based technique presents a potential approach to use carbon fiber-reinforced polymers waste and manufacture high-performance engineering, economic, and environmentally friendly industrial applications with the complicated design using different polymer matrices.

Structural response of glass fiber-polymer composite bending-active elastica beam under long-term loading conditions

Bending-active elastica beams represent structural members which are initially installed as straight beams and then bent into arched shapes by applying horizontal displacements to one support. Designing such members for permanent structures made of fiber-polymer composites involves complex viscoelastic responses, which have not yet been thoroughly investigated. An experimental investigation of medium-scale bending-active elastica beams, consisting of pultruded glass fiber-polymer composite profiles, was thus conducted to investigate the long-term structural behavior of such members under imposed sustained bending and axial compression. The results revealed that viscoelastic responses are based on an interaction of stress relaxation and creep with their effects increased with increasing bending degree and time of exposure to sustained strains and stresses. The imposed horizontal displacement to one of the supports to maintain the bent beam shape induced sustained bending stresses in the beam. Beneficial relaxation of these stresses occurred with relaxation predicted to reach 12 % during a targeted 50-year design service life. Furthermore, the likelihood of the curved beam exhibiting in-plane deformations under sustained stresses enabled creep to occur simultaneously, with associated in-plane creep deformations and strength reduction. While creep deformations remained insignificant, progressive creep rupture occurred at highest bending degrees, exhibiting sequential creep rupture in the outer combined mat layers, delamination, crack opening and final fiber failure. Creep rupture can be prevented by postponing crack initiation in the combined mat layer beyond the targeted design service life. This can be achieved by limiting the bending degree to 50 % of the bending degree at which short-term crack initiation occurs.

Environmental sustainability and waste conversion of Prosopis juliflora fibre-reinforced ZnO nanofiller particulates PLA composite- mechanical and thermal analysis

The presence of large quantities of Prosopis juliflora (PJ) fibers in natural habitats presents substantial threats to the environment and economies of numerous developing countries. Utilizing natural fibers in polymer composites can effectively enhance their characteristics. The primary objective of this study is to create a composite material by combining Prosopis Juliflora (PJ) fiber with a polylactic matrix that has been combined with zinc oxide nanofillers. The fabrication process will involve the hand layup technique. In order to have a comprehensive understanding of the mechanical characteristics, thermal behavior, and thermal stability of the PJ composite, it is necessary to undertake additional investigations. The results showed that the inclusion of zinc oxide filler enhanced the tensile strength (67.29 MPa), flexural strength (64.27 MPa), compressive strength (56.79 MPa), and impact energy (34 J) in sample S5. Additionally, the thermal properties, including thermal conductivity, thermal expansion, and short-term heat resistant capacity, were also improved by the addition of zinc oxide filler in sample S5. The deterioration temperature of the PJ composite was determined to be between 312 and 342 °C using thermogravimetric analysis. The failure mode of the PJ composite was investigated using scanning electron microscopy.

Enhancement of mechanical and structural characteristics through the hybridization of carbon fiber with Cordia‐dichotoma/polyester composite

AbstractSingle fiber polymer composites containing either natural or artificial fibers may not deliver the desired characteristics. The current study used the hand‐layup technique to make a hybrid composite by incorporating the natural fiber, Cordia‐dichotoma (CD) and artificial fiber, carbon fibers (CF) in a polyester matrix and compressing the mixture for the desired size. The current study investigates the influence of carbon fiber loading (0, 5, 10, and 15 wt%) on the mechanical, structural, and crystalline properties of CD/polyester composites keeping the total fiber loading at 20 wt%. Mechanical properties are investigated with a universal testing machine, and impact strength using Izod impact apparatus. Better mechanical properties (tensile strength‐457.38 MPa; flexural strength‐290.09 MPa and impact strength‐346.46 J/m) were obtained for the pure carbon fiber composite arranged in four layers (CF/CF/CF/CF), followed by hybrid composite (CF/CD/CD/CF) (tensile strength‐319.24 MPa; flexural strength‐253.03 MPa and impact strength‐291.34 J/m) whereas pure CD fiber (CD/CD/CD/CD) composite yielded the lowest values (tensile strength‐117.96 MPa; flexural strength‐164.99 MPa and impact strength‐118.11 J/m). Composites undergo hybridization, which improves their mechanical properties, lowers their cost, and makes them more environmentally friendly. The characteristics of the specimens were examined using Fourier Transform Infrared Spectroscopy (FTIR), X‐ray Diffraction Analysis (XRD), Atomic Force Microscope (AFM), and Scanning Electron Microscopy (SEM). According to findings, crystallinity index is increased from 77.94% for CD/CD/CD/CD composite and increased to 78.21% for CF/CD/CD/CF composite. Highest crystallinity index of 82.46% was obtained for CF/CF/CF/CF composite. These hybrid composites may be used for applications involving medium loads.Highlights In this study, Cordia‐dichotoma natural fibers are extracted and treated with alkali (NaOH) to reduce the biodegradability. To lower the cost and enhance mechanical and biodegradable properties Carbon and cordia‐dichotoma fibers have been hybridized. Mechanical Properties such as tensile, flexural and impact properties are evaluated for the prepared hybrid composites. Hybrid composites were analyzed using FTIR, AFM, XRD, and SEM to assess their suitability to various applications.

Comparative study on shape memory, mechanical, and thermomechanical properties of multi‐walled carbon nanotubes and graphene nanoplatelets modified bidirectional (twill) carbon fiber polymer composites

AbstractThe research conducts a comparative analysis of epoxy/bi‐directional (twill) carbon fiber three‐phase shape memory hybrid composites modified with MWCNT and GnP, examining their mechanical, thermomechanical, and shape memory properties. Fabrication involves preparing nanoparticle‐modified epoxy nanocomposites through ultrasonication followed by hand layup technique. The findings revealed that the modified composites achieved their optimal performance at a 0.6 wt% concentration of nanoparticle, with the tensile strength and modulus increasing by 33.59% and 23.47% for 0.6 wt% MWCNT composite and by 45.94% and 25.61% for 0.6 wt% GnP composite. GnP‐modified composites outperformed MWCNT ones due to GnP's sheet structure aligning parallel to the load and larger surface area facilitating enhanced interaction with the matrix. Despite polymer modification, the shape recovery ratio values remained high, with 98.92% for unmodified composite, 97.72% for 0.6 wt% MWCNT composites, and 97.12% for 0.6 wt% GnP modified composites, all exceeding 90%, indicating no compromise in performance.

The impact of various curing methods on the curing process of polymer-fiber composites analyzed using analytical approach

Ti/Gf/Cf represents a novel form of hybrid fiber metal laminates (HFMLs) that successfully blend the benefits of titanium alloy, glass fiber reinforced plastic (GFRP), and carbon fiber reinforced plastic (CFRP). These materials have garnered attention in the field of engineering due to their exceptional levels of stiffness, strength, and shear resistance. The quality of HFMLs during the curing process was significantly impacted by the chosen curing method. Moreover, the use of multiple types of fibers complicated the optimization of curing parameters in HFMLs. A comprehensive study was conducted using a multi-physics field coupling finite element method to investigate the impact of various curing methods on the development of temperature distribution, curing degree, and curing stress in HFMLs during the curing process. By integrating thermal transmission equations, curing kinetics, and viscoelastic mechanical models, a detailed curing simulation model was established. Increasing the cooling rate from 1 °C to 5 °C was shown to raise the maximum curing stress by 4.7 MPa. Additionally, higher curing temperatures were found to induce internal curing stress due to variations in thermal properties. Insufficient insulation times were observed to exacerbate non-uniform temperature distribution and curing degree fields in HFMLs, potentially leading to increased internal stress. To mitigate the generation of large residual stress, it is recommended to lower the heating and cooling rates, reduce curing temperatures, and extend the insulation time appropriately during the curing process of HFMLs. The primary goal of this research was to accurately predict the evolution of curing parameters in HFMLs under different curing regimes, which were impacted by the chosen curing method. The results of the study demonstrated that rapid changes in temperature during heating and cooling stages can lead to uneven curing, resulting in the accumulation of residual stress within the laminates.

Optimization of microwave-produced coal-derived char insulation foam using response surface methodology

A new char-based insulation foam (CIF) is developed using coal-derived pyrolysis char (PC) and lignin, a paper and pulp industry byproduct. In this study, CIF is prepared by adopting the microwave method and Response Surface Methodology (RSM) is utilized to optimize predictions about the properties such as thermal conductivity, foam texture, compressive strength, and pore distribution of CIF. The three independent variables including percent char content, lignin/char ratio, and foaming agent/polyol ratio are considered in the RSM methodology. The face-centered central composite design is selected to obtain 17 test runs. Optimization of the predicted responses is performed to find the recipe considering a composite desirability function. Confirmatory test results show agreement between the predicted and observed values, with the percent error ranging from 0.00 % to 11.35 %, thereby confirming the accuracy of the prediction equations. The optimized CIF exhibits a thermal conductivity of 0.0633 W/m.K and a compressive strength of 695 kPa making it comparable to or better than traditional building insulation products such as fiber insulation, polymer composite, particle board, and ceramic glass foam. Therefore, this new CIF has the potential to be used as an energy-saving insulation material for building envelopes.

Lignocellulose sustainable composites from agro-waste Asparagus bean stem fiber for polymer casting applications: Effect of fiber treatment

In the past decades, lignocellulose fibers have attracted significant attention due to their low density, environmental friendliness, and biodegradability. Consequently, researchers are intensifying their efforts to explore the potential of lignocellulosic fibers as sustainable alternatives to synthetic fibers in polymer composites. Among various natural fibers identified as potential reinforcements, agro-waste from the Asparagus Bean stem (ABS) which has been discarded as landfill after harvest has emerged as a promising source of lignocellulose fibers for promoting sustainability. This study investigates the reinforcement suitability of ABSF in polymer matrices. A water-retting process was used for extraction, followed by treatment with a 5 % alkali solution. Cellulose content was enhanced to 65 wt%, and fiber density increased to 1.13 g/cm3 after chemical treatment. Thermogravimetric analysis indicated improved thermal stability of the treated fibers up to 247 °C. Morphological analysis showed increased surface roughness and impurity removal. To evaluate the reinforcing effect of the chemical treatment, epoxy composites with 10 wt% reinforcement were developed. The mechanical properties of these composites improved significantly, with more than 1.1 times when used alkali-treated ABSF as reinforcement. Flexural properties were substantially enhanced, with flexural strength increasing from 90.53 MPa to 122.71 MPa and flexural modulus from 2.41 GPa to 2.95 GPa due to better fiber-matrix interaction and removal of weak, amorphous constituents. The primary objective of this study is to demonstrate that ABSF is a viable alternative raw material for composite reinforcement, suitable for developing lightweight structural applications.

A Comprehensive Review of Recent Developments on the Natural Fiber Reinforced Polymer Matrix Composites for Automotive and Sports Application: Materials, Processes and Properties

Now a days, the world has been evolving and adapting to advance technology; as a result, the development and expansion of Composite materials have been growing day by day.. Natural fibres are a feasible and eco-friendly alternative to synthetic fibres for polymer composite reinforcing. Materials are attractive because they are economical, environmentally friendly, abundant in nature, and have mechanical properties[60]. Natural fibres are given first priority above all other types of fibres due to their appealing qualities include biodegradability, minimum cost, environmental friendliness, high strength-to-weight ratio in engineering goods, and low health risks. An overview of recent trends in physio mechanical characteristics, thermal properties, morphological behaviour, surface treatment, design optimisation with the ANOVA technique, the effect of Mercerization and SEM analysis, microstructural interfacial adhesion, and the various methodologies used to measure these properties. Keywords: Natural fiber polymer composites, Physio mechanical properties, SEM Analysis, Thermal properties, ANOVA technique, Applications.

Wet-Spinning Carbon Nanotube/Shape Memory Polymer Composite Fibers with High Actuation Stress and Predesigned Shape Change.

Actuators based on shape memory polymers and composites incorporating nanomaterial additives have been extensively studied; achieving both high output stress and precise shape change by low-cost, scalable methods is a long-term-desired yet challenging task. Here, conventional polymers (polyurea) and carbon nanotube (CNT) fillers are combined to fabricate reinforced composite fibers with exceptional actuation performance, by a wet-spinning method amenable for continuous production. It is found that a thermal-induced shrinkage step could obtain densified strong fibers, and the presence of CNTs effectively promotes the tensile orientation of polymer molecular chains, leading to much improved mechanical properties. Consequently, the CNT/ polyurea composite fibers exhibit stresses as high as 33MPa within 0.36 s during thermal actuation, and stresses up to 22MPa upon electrical stimulation enabled by the built-in conductive CNT networks. Utilizing the flexible thin fibers, various shape change behavior are also demonstrated including the conversion between different structures/curvatures, and recovery of predefined simple patterns. This high-performance composite fibers, capable of both thermal and electrical actuation and produced by low-cost materials and fabrication process, may find many potential applications in wearable devices, robotics, and biomedical areas.

Analysis of thermomechanical and dynamic characteristics of treated saccharum munja fiber polymer composite

Analysis of thermomechanical and dynamic characteristics of treated saccharum munja fiber polymer composite