Polymer Matrix Composites Research Articles

Development of Bamboo Based Nylon 66 Composite through Friction Stir Processing-An Attempt

The concept of developing a bamboo-based Nylon 66 polymer matrix composite is a relatively novel and very new technical attempt through friction stir processing (FSP). This innovative approach can create a composite material that strengthen the mechanical properties of bamboo and the versatility of Nylon 66. However, successful implementation requires careful consideration of FSP process parameters such us tool rpm, traverse speed, tilt angle and tool design. Among the processing parameters, the tool rpm shows the significant role for severe plastic deformation and temperature generation which leads to the achieving excellent bond. Therefore, in this present study attempt has made to develop the polymer matrix composite (nylon 66 and bamboo powder) using FSW process at a variant rotational speed of 300,400 and 500 rpm with the constant traverse speed of 25 mm min-1. The deformation behavior and the peak temperature evolved under the tool shoulder during the stirring motion is studied using COMSOL Multiphysics simulation. It is found that, the specimen processed with higher rpm (500rpm) shows the higher volumetric strain and the peak temperature and it is evident that with increasing rpm the higher amount of severe plastic deformation occurred. Initially the process parameters are optimized without bamboo powder on the nylon 66 plate of 6 mm thickness and found that the 500 rpm processed specimen shows the defect free. Prior to the actual FSP, the small keyways taken on the center of the nylon 66 plate in order to add the bamboo powders in it. Actual processing was done with bamboo powder after adding natural bamboo powder of size 50µm. The result reveals that, the bamboo powder has partially expelled out during the period of FSP. This complete study concedes that the processing parameters needs to be optimized and also bamboo added method need to be studied for the successful development of bamboo-based polymer matrix composite.

Machinability characteristics study on hibiscus rosa-sinensis reinforced polymer composites using soft computing techniques

Abstract Understanding the drilling behaviour of composite materials is crucial for optimizing their manufacturing processes and enhancing their applicability across various industries. In this study, the drilling process of Hibiscus Rosa-Sinensis Polymer matrix composites is investigated due to the significance of investigating such advanced and sustainable composite materials for their potential applications. Hibiscus Rosa-Sinensis Fibers are extracted and processed from the outer bark of the hibiscus plant, are incorporated into polymer matrices in varying weight percentages (0 Wt%, 10 Wt%, 20 Wt%) to form discontinuously reinforced polymer composites. Samples with uniform dimensions of 150 × 75 × 15 mm, are used for the drilling operation using Ace Micromatic DTC-400 instrument. The project focuses on analysing the influence of key drilling input parameters such as Spindle speed, Feed rate and HRS (Hibiscus Rosa-Sinensis) Fiber weight percentage on the Thrust Force (N) and Torque (N-m) generated during drilling operations. Taguchi’s Design of Experiments with L27 orthogonal array is used to systematically optimize the input parameters to gain insights into the drilling behaviour of these composite materials. Further a second order mathematical model has been generated for Thrust Force and Torque using Response Surface Methodology (RSM). Thrust Force and Torque during drilling are measured using 9257 BA KISTLER Dynamometer coupled with DynoWare 2825 A software. The findings of this study not only contribute to a deeper understanding of the drilling process but also hold significant implications for industries reliant on composite materials. From aerospace to automotive sectors, where lightweight and durable materials are essential, to construction and renewable energy industries seeking sustainable alternatives, the application potential of hibiscus Rosa-Sinensis Fiber-reinforced composites is vast. By elucidating the intricate dynamics of drilling operations on these materials, this research paves the way for enhanced manufacturing processes and the development of advanced composite structures tailored to meet the demands of diverse industrial applications.

Fabrication and High Dielectric Properties of Sandwich-Structured Ba0.6Sr0.4TiO3/Polyvinylidene Fluoride Layered Composites with Multiscale Parallel Interfaces.

Ba0.6Sr0.4TiO3/polyvinylidene fluoride (BST/PVDF) dielectric functional composites have been widely used in flexible wearable devices, capacitors, and energy storage devices. In addition to the ceramic phase type, polymer matrix type, composition, and interfacial connectivity of BST/PVDF composite materials, their morphology also significantly influences their electrical characteristics. Therefore, herein, sandwich-structured BST/PVDF layered composites were designed and prepared via tape-casting processing using different types of BST fillers [i.e., formless zero-dimensional (0D)-BST, rod-like one-dimensional (1D)-BST, and plate-like two-dimensional (2D)-BST]. The microstructures and electrical characteristics of sandwich-structured BST/PVDF composites were studied in relation to the BST morphology. The effects of the internal mechanisms of different interfacial models on the breakdown strength of BST/PVDF composites were discussed. According to our findings, unlike the 0D-BST and 1D-BST powders, 2D-BST powders form multiscale parallel interfaces in sandwich-structured composites due to their unique lamella-like morphology, which enhances the breakdown strength of sandwich-structured composites. Sandwich-structured BST/PVDF composites containing 2D-BST powders exhibit good electrical characteristics with an energy storage density of 19.71 J/cm3, an energy storage efficiency of 85.3%, a dielectric constant of 30.4 (1 kHz), a dielectric loss of 0.036 (1 kHz), and a dielectric tunability of 93.2%. This study provides a method for preparing functional composites with high dielectric tunability and high energy storage characteristics.

Ti3C2Tx-UHMWPE Nanocomposites-Towards an Enhanced Wear-Resistance of Biomedical Implants.

There is an urgent need to enhance the mechanical and biotribological performance of polymeric materials utilized in biomedical devices such as load-bearing artificial joints, notably ultrahigh molecular weight polyethylene (UHMWPE). While two-dimensional (2D) materials like graphene, graphene oxide (GO), reduced GO, or hexagonal boron nitride (h-BN) have shown promise as reinforcement phases in polymer matrix composites (PMCs), the potential of MXenes, known for their chemical inertness, mechanical robustness, and wear-resistance, remains largely unexplored in biotribology. This study aims to address this gap by fabricating Ti3C2Tx-UHMWPE nanocomposites using compression molding. Primary objectives include enhancements in mechanical properties, biocompatibility, and biotribological performance, particularly in terms of friction and wear resistance in cobalt chromium alloy pin-on-UHMWPE disk experiments lubricated by artificial synovial fluid. Thereby, no substantial changes in the indentation hardness or the elastic modulus are observed, while the analysis of the resulting wettability and surface tension as well as indirect and direct invitro evaluation do not point towards cytotoxicity. Most importantly, Ti3C2Tx-reinforced PMCs substantially reduce friction and wear by up to 19% and 44%, respectively, which was attributed to the formation of an easy-to-shear transfer film.

An artifactual fibre overlap removal algorithm for micro-computed tomography image post-processing and 3D microstructure generation with graphics processing unit acceleration

A novel algorithm based on radial basis functions is proposed for the removal of artifactual fibre overlap within fibre structures extracted from micro-computed tomography (micro-CT) images of fibre reinforced polymer matrix composites. The proposed algorithm is highly efficient and excels in preserving the original fibre structures extracted from the micro-CT images. Besides, graphics processing unit (GPU) acceleration is applied to further enhance the efficiency of the fibre overlap removal process. Furthermore, the proposed algorithm is also modified for the generation of periodic 3D microstructures. For practical application, the proposed algorithm is implemented for both the artifactual fibre overlap removal within micro-CT images from an injection moulded part and the microstructure generation for 3D printed samples. The unidirectional elastic modulus of the resultant microstructures is computed via numerical simulations and shows a close match to the experimental measurements with relative errors less than 2%. Overall, the proposed algorithm significantly facilitates the reconstruction of micro-CT image-based numerical models and can also be easily repurposed to generate complex microstructures, which is of great value for the development of data-driven models for characterization and design of composite materials that demands large amounts of data on material microstructures.

Characteristics of surface modified sugarcane bagasse cellulose: application of esterification and oxidation reactions

Research on polymer matrix composites has become increasingly important in both the academic and industrial sectors. The study of polymer-natural fiber composites, known for their eco-friendly properties, has gained significance. Sugarcane bagasse fibers, abundant as discarded agricultural byproducts, offer improved properties such as density, rigidity, strength, and cost-effectiveness, enhancing sustainability. As a result, experiments were performed on cellulose fibers pre-treated from sugarcane bagasse using 5% NaOH solution by simply soaking them for 4–5 h followed by washing with water. Further modifications involved esterification using phthalic anhydride and phthaloyl chloride via steam baths at 90 °C and oxidation using sodium percarbonate with a phase transfer catalyst (Adogen) at 80 °C. These chemically altered cellulose fibers exhibited significant peak changes in the FTIR spectra, a reduced crystallinity index in the XRD pattern, increased thermal stability as evidenced by TGA curve, and improved surface roughness in the SEM analysis. This paper emphasizes successful pretreatment procedures for isolating cellulose fibers from sugarcane bagasse and introduces three chemical treatments for surface functionalization which might find applications in the preparation of biocomposites.

Effects of SiO2-coated CNTs on the directional formation of SiC whiskers and improvement in the ablative resistance of polymer-matrix composites

As the development of hypersonic aerospace technology progresses, greater challenges are presented for solid rocket motors (SRMs) thermal protection, and the ablation performance of insulation materials needs to be further improved. Carbon nanotubes (CNTs) as a new type of reinforcing nano-filler, readily react with the oxidative components in the working gas during SRMs operation, limiting their excellent performance. In this study, we propose to coat the commonly used reinforcing filler, SiO2, on the surface of CNTs to suppress their susceptibility to oxidation and investigate the effects of adding CNTs, SiO2, and CNTs@SiO2 to the matrix on material properties. The results show that the addition of CNTs@SiO2 significantly improves the ablation resistance of the insulation material, with the linear ablation rate of M-@SiO2-2 being 56 % lower than that of M-SiO2-2. Based on the analysis of the material's antioxidation performance and the strength of the resulting char layer after ablation, the reasons for the improvement of ablation performance are discussed. By conducting high-temperature tube furnace tests, the composition and structure of the char layer at different temperatures are studied, and it is found that CNTs in the CNTs@SiO2 formulation can directly provide the carbon source required for the carbon thermal reduction reaction, promoting the directional growth of SiC whiskers. Based on these findings, an ablation mechanism is proposed.

Impact of Manufacturing Methods on the Mechanical Characteristics of Polymer Matrix Composites with Glass and Epoxy Fiber Reinforcement

Impact of Manufacturing Methods on the Mechanical Characteristics of Polymer Matrix Composites with Glass and Epoxy Fiber Reinforcement

Characterization and property prediction of fibre structures within discontinuous-fibre reinforced polymer matrix composites using 3D fibre cells assisted by contrastive learning

Fibre-cell-based fibre structure characterization approach was proposed recently to characterize the fibre distribution within discontinuous-fibre reinforced polymer matrix composites (DFR PMCs) over a 2D domain. This approach determines the distribution state of each fibre based on the relative size and topological features of its fibre cell. In this study, the fibre-cell-based approach is extended for 3D fibre domains. A convolutional neural network (CNN) encoder is trained through contrastive learning to quantitatively represent topological features of 3D fibre cells. Subsequently, the feature–property correlations are established using an artificial neural network (ANN). For practical application, the ANN is integrated with an image analysis software to provide in situ predictions of local elastic modulus of a DFR PMC based on its fibre structures observed from micro-CT images. The predictions are also compared with the experimental measurements acquired through microindentation testing, and it shows a good agreement.

Characterization of Novel Cellulosic Salvadora Persica Fiber for Potentiality in Polymer Matrix Composites

ABSTRACT Natural fiber is expected to make polymer composites light and environmentally friendly. In this paper Salvadora persica natural fiber is characterized in view of its use in composite materials for the first time. Average diameter of the fiber was 250 µm and density was 1.3 g/cm3. The surface of the fiber was irregular with impurities and surface features such as shallow tubs, cell walls and lignin were revealed by Scanning Electron Microscopy (SEM). X-ray diffraction (XRD) analysis reveals Crystallinity Index (C.I) of 58% and Crystallite Size of 3.58 nm. The chemical bonds pertaining to different constituents of the natural fiber such as cellulose, hemicellulose and lignin were identified by Fourier Transform Infrared (FTIR) spectroscopic analysis. In the thermal degradation of the fiber during the Thermogravimetric analysis (TGA), three stages were identified. The maximum thermal degradation temperature (Tfinal) was determined to be 357°C. Tensile strength, Young’s modulus and percentage elongation of the fiber were 430 ± 100 MPa, 16 ± 3.9 GPa and 4.2 ± 0.91% respectively.

Comparison studies on acoustic behaviour of natural fibre-reinforced polymer matrix composites

Comparison studies on acoustic behaviour of natural fibre-reinforced polymer matrix composites

Development of Natural Fiber Reinforced Polymer Matrix Composites: A Critical Review

AbstractFiber reinforced composites are made by reinforcing fibers in a polymeric matrix and shaping them to fit. Natural fibers, on the other hand, such as jute sisal, hemp, flax etc. are increasingly commonly utilized as reinforcements and perform similarly to artificial fibers. Man‐made fibers like as carbon, glass, and kevlar are utilized as reinforcements in the start and have shown to be the best in terms of characteristics, reinforcing capacity, and usefulness. Research investigations also show that when man‐made and natural reinforcements are combined in a hybrid form, the composite characteristics increase significantly. The composite material obtains all of the better qualities of individual fibers as a result of this combination, and when the composite is subjected to varying loads, each fiber gives its own maximal resistance. The chemical and physical properties are further enhanced by including particular reinforcements into polymer matrix composites, which provide whole new features (which has transformed the aerospace, marine, defence, and automobile industry). As a result, the composite would be better in all attributes. The current study provides a thorough examination of the different challenges concerning the synthesis and mechanical characterization of natural fiber reinforces hybrid polymer composites. Future difficulties, as well as areas of use for polymer matrix composites, have been investigated that may aid in the elimination of plastic waste and the reduction of environmental pollution.

Mechanochemically assisted synthesis, inversion degree and magnetization of spinel compounds across the (Zn,Mg)Fe2O4 system for flexible smart devices

Magnetic spinel oxides are multifunctional materials used or under consideration for a range of applications across electronics, communication technologies, remediation and health. They can also present high magnetostriction coefficients, and are being investigated as active inorganic fillers in polymer matrix composites for flexible sensors and actuators. However, state-of-the-art materials for these later applications are NiFe2O4- and CoFe2O4-based compositions, and it is necessary to find environmentally-friendly alternatives free of toxic elements that provide comparable responses, ideally biocompatible. This work presents a study of the spinel phases across the (Zn,Mg)Fe2O4 system and of their suitability to be used as magnetic component in hybrid composites. Spinel single phase materials with variable particle size across the submicron range, down to the verge of the nanoscale, have been obtained by mechanochemically assisted synthesis for five selected compositions spanning the whole ZnFe2O4-MgFe2O4 system. Evolution of the crystal lattice and inversion degree (amount of Fe3+ at tetrahedral site) has been obtained from Rietveld refinement of synchrotron X-ray diffraction data, and correlated with the development of magnetic ordering. Ferrimagnetic compositions are identified, among which Zn0.25Mg0.75Fe2O4 stands out for its magnetization characteristics comparable to NiFe2O4. This spinel compound is thus a promising environmentally-friendly candidate for flexible devices, in principle also biocompatible.

Structural Analysis and Mass Optimization of Mobility Walkers Using Lightweight Polymer Matrix Composites

Structural Analysis and Mass Optimization of Mobility Walkers Using Lightweight Polymer Matrix Composites

Exploring the influence of specimen types on the intralaminar fracture behavior of fiber-reinforced polymer matrix composites

The accurate determination of fracture toughness of fiber-reinforced composites is critical for the assessment of structural integrity. Although there have been many studies on the intralaminar fracture behavior of composites, satisfactory results have not yet been obtained regarding the influence of specimen types. In this paper, commonly used fracture specimens (DCT, CT, ESET, pin-loaded SENT and clamped SENT specimen) are applied to study their applicability in the fracture behaviors of composites with different orientations. And the impact of data processing methods for the area method, GC-compliance and GC-stress intensity factors on fracture performance was analyzed. The results showed that the above three data processing methods have obtained relatively consistent fracture properties. Different specimens obtained significantly various results, showing a gradually decreasing trend from clamped SENT, ESET, pin-loaded SENT, CT to DCT. Furthermore, considering that the clamped SENT specimen is closest to the Mode-I fracture toughness obtained from the DCB specimen, and there is no compression damage in the experiments under different orientations, this specimen type is the most recommended specimen. Finally, the failure mechanisms of carbon fiber-reinforced composite under different specimen types and orientations were revealed. As the orientation angle increases (β from 0° to 90°), the failure mode gradually transitions from matrix cracking and interface debonding to matrix shear and fiber fracture. The above achievements will contribute to a deeper understanding of the intralaminar fracture process and failure mechanism of fiber-reinforced composites.

Quantification of delamination resistance data of FRP composites and its limits

Quantitative delamination resistance data of fibre-reinforced polymer-matrix (FRP) composites for quasi-static or cyclic fatigue loads are determined under different loading modes and load rates, respectively. Such data find use, e.g., in FRP materials’ development, materials’ selection, assessment of durability, or structural design. Round robins during test development yielded repeatability and reproducibility (coefficients of variation) of roughly 10 to 25%. This scatter has several different sources. Intrinsic material variability amounts to a few percent at best, at least for advanced manufacturing processes. This intrinsic scatter is essential for material comparisons and structural design. Measurement resolution specified in standardised test procedures yields a maximum of 4–5% variability. Most of the remaining scatter comes from other, extrinsic sources. Test operator actions, e.g., choice of test set-up, manual data acquisition or data analysis can yield extrinsic scatter. Damage mechanisms during delamination initiation and propagation act on the micro- and meso-scale, typically a few micrometer to a few hundred micrometer in size, with corresponding time-scales estimated to between a few tens of nanoseconds and a few microseconds. Defect size-scales are hence several orders of magnitudes lower than test specimen and structural scales, respectively. Predictive capability of models using such test data for structures are, therefore, limited. Major issues are up-scaling from straight beam-like specimens to larger shell-like structures, possibly with complex shape and varying thickness as well as from unidirectional fibre orientation to multidirectional lay-ups.

The effect of nanocellulose and silica filler on the mechanical properties of natural fiber polymer matrix composites

Natural fiber-reinforced polymer matrix composites recently got great attention in biomedical applications due to their inherent characteristics such as biocompatibility, lightweight, and biodegradability. However, natural fiber composites suffer from poor mechanical properties and weak interfacial adhesion. It is well documented that the addition of nanofiller has improved the mechanical properties of different synthetic fibers such as glass and carbon composites. The main objective of this paper is to study nanofillers' effect on the mechanical properties of unidirectional false banana fibers reinforced polymer composites. The filler materials, crystalline nanocellulose fibrils, and crystalline nanosilica particles were extracted from sugarcane bagasse and its byproducts. The composite samples were fabricated by adding the nanofillers in unidirectional natural fibers arranged in four fiber orientations (0°, 0o/90o ±45o, and quasi-isotropic), and their tensile, flexural, compression strength, thermal stability, and void content were measured following ASTM standards. The results revealed that adding nanofillers increased the tensile, flexural, and compressive strengths by 16 % (98.83 Mpa), 11 % (161.60 Mpa), and 23 % (114.62 Mpa), respectively. Similarly, at 0° orientation, the addition of nanoparticles enhances the tensile, bending, and compressive modulus by 30 % (15.43 Gpa), 12 % (13.52 Gpa), and 60 % (42.6 Gpa), respectively. On the other hand, the void content was reduced with the addition of nanofillers. The results also revealed that composites with crystalline nanosilica particle fillers had superior thermal stability compared to crystalline nanocellulose fibril fillers. The overall results of this research give the confidence that nano particle-filled natural fiber composites can be used for bio-based engineering applications, such as prosthetic sockets.

Structure and tribological behavior of a polyetherimide/polytetrafluoroethylene matrix filled with negative thermal expansion zirconium tungstate particles

Thermal expansion mismatch stresses may be a reason for premature failure of sealing and bearing components made of polymer composites that are rubbed against metallic surfaces at elevated temperatures. It is of particular importance for polymer matrix composites loaded with anti-friction inclusions of polytetrafluoroethylene (PTFE) that possesses high coefficient of thermal expansion. In this regard, a study was undertaken to elucidate the effect of the thermal mismatch on wear and friction of amorphous polyetherimide (PEI) matrix loaded with either polytetrafluoroethylene (PTFE) particles (i) or PTFE particles covered with negative thermal expansion zirconium tungstate (ZT) α-ZrW2O8 (ii) at temperatures 23 °C, 120 °C and 180 °C. The ball-on-disk testing scheme was used according to standard with AISI 52100 steel balls rubbed against a polymer composite disks at normal force P = 5 N and sliding velocity V = 0.3 m/s. The PEI/PTFE/ZT composite demonstrated a tendency for wear rate (WR) reduction in sliding at 120 °C and 180 °C as compared to corresponding WR enhancement on the PEI/PTFE. The rationale is provided that the ZT additive effectively reduced thermal expansion of the PTFE in the PEI matrix and thus improved wear resistance of the composite. New thermal expansion-controlled wear and friction instability mechanism has been proposed and discussed.

Damage assessment in composite plates using extended non-destructive self-heating based vibrothermography technique

Self-heating based vibrothermography (SHVT) is a promising non-destructive technique for inspecting polymer-matrix composites (PMCs) in circumstances with limited external heating feasibility, functioning under the resonant frequency excitation. This study broadened the applicability of SHVT technique for two-dimensional (2D) PMCs by examining its sensitivity and effectiveness in detecting and quantifying damage within 2D laminated composites across nine different scenarios. Atwo-step algorithm based on the concepts of the boundary of effective thermograms, and the maximal temperature ratio was proposed to methodically choose the optimal raw thermogram from a large set of registered thermograms for each scenario. The issues linked to blurred damage signatures in the raw infrared (IR) images adversely affected the overall sensitivity and accuracy of SHVT. Implementing the algorithm based on central moments improved the overall damage detectability using this technique. Additionally, the introduced hit/miss metric enabled the damage identification and quantification for all scenarios.

Impact response and compression-after-impact properties of foam-core sandwich composites incorporating scrap tyre rubber particles

Integrating scrap rubber particles as fillers into polymer matrix composites offers a cost effective and environmentally sustainable pathway to manage tyre waste through the creation of value-added products. This research explores the low-velocity impact (LVI) response and compression after impact (CAI) properties of rubberised foam-core glass fibre-reinforced epoxy (GFRE) sandwich composites. Syntactic foam cores integrated with rubber particles were manufactured using vacuum-assisted resin transfer moulding (VARTM). The compression properties of rubberised foam core, vital for resisting impact damage during LVI, were examined. Results show more than 40% reduction in compression strength and modulus of the syntactic foam upon the inclusion of 33 wt.% rubber particles. The LVI response and residual compression properties of rubberised foam-core composites were also evaluated. Rubberised foam cores caused a marginal reduction in the peak impact force and led to approximately 60% reduction in the delamination area. The pre-impact compression strength was unaffected by rubber particles within the core as the GFRE face sheets carried most of the compression load. Post-impact compression strength was slightly higher in rubberised foam-core composites due to reduced delamination. Digital Image Correlation (DIC) analysis tracking of the strain evolution during CAI experiments revealed the stress-raising effect of the impact damaged region. This study showcases sustainable scrap tyre management through the inclusion of rubber particles into foam-core composites without substantially reducing in-plane compression properties before or after low-velocity impact.