Polymer Composites Research Articles

Effect of chemical treatments of fibre surface on mechanical properties and wear rate of Beerakaya (Luffa acutangula) reinforced epoxy polymer composites

Effect of chemical treatments of fibre surface on mechanical properties and wear rate of Beerakaya (Luffa acutangula) reinforced epoxy polymer composites

Investigation of cutting forces of glass sphere reinforced polymer composites

AbstractIn this study, the effects of reinforcement ratio, drill bit material, and drilling process parameters on the cutting forces generated during the drilling of glass sphere‐reinforced polypropylene composites were investigated experimentally. Test specimens were produced by conventional injection‐moulding of glass sphere reinforced polypropylene composite materials at 5 %, 10 % and 20 % wt. ratios. High speed steel, titanium‐coated high‐speed steel, and carbide drill bits with 4 mm diameter were preferred for drilling. In addition, the drilling process was carried out on a 3‐axis computer numeric control milling machine. Three different feed rates of 0.05 mm/rev, 0.10 mm/rev, and 0.15 mm/rev and cutting speeds of 12 m⋅min−1, 16 m⋅min−1, and 20 m⋅min−1 were determined for the drilling process. In addition, Taguchi experimental optimization method, analysis of variance and scanning electron microscopy were used to investigate the morphology of the drilled surface and the wear mechanisms occurring on the drill bit due to the drilling process. The test findings showed that the maximum torque value was 54.64 N⋅mm and the maximum thrust force was 100.43 N. The optimum test parameter for cutting forces was observed as C1D3FR1CS3. Drill parameter had an effect of 40.96 % on thrust force and 36.11 % on torque.

A novel melt extrusion method for efficient and large-scale in-situ exfoliation of boron nitride to prepare high performance thermal conductive polymer composite

The polymer/hexagonal boron nitride (h-BN) thermal conductive composite an excellent candidate for thermal management materials due to its insulation properties. However, it is a challenge to achieve efficient large-scale exfoliation of h-BN through melt blending to balance thermal conductivity and mechanical properties. In this work, an innovative melt mixing strategy using the co-rotating non-twin screw extruder (NTSE) was developed to prepare the high-density polyethylene (HDPE)/h-BN composites with excellent overall performance. The results were well compared with those of conventional twin screw extruder (TSE). The NTSE triggers chaotic mixing and provides a strong elongation flow field capable of h-BN efficiently exfoliating into a few layers, while simultaneously ensuring uniform dispersion and distribution within HDPE. The in-plane thermal conductivity and elongation at break of the NTSE composite with 10 wt% h-BN addition were 7.63 W∙m−1 K−1 and 653.1 %, which were 74.7 % and 70.3 % higher than those prepared by TSE, while the enhancement rates rose to 174.6 % and 74.4 % when 30 wt% h-BN was added, respectively. The in-plane thermal conductivity enhancement ratio of NTSE was more than 3000 % when the h-BN content was higher than 10 wt%. Besides, the thermal stability, crystallinity, and thermal diffusion of the NTSE composites were also enhanced to different degrees. This strategy is efficient to coordinating the conflicting between the comprehensive performance and large-scale preparation of thermally conductive polymer composites.

Machine Learning in 3D and 4D Printing of Polymer Composites: A Review.

The emergence of 3D and 4D printing has transformed the field of polymer composites, facilitating the fabrication of complex structures. As these manufacturing techniques continue to progress, the integration of machine learning (ML) is widely utilized to enhance aspects of these processes. This includes optimizing material properties, refining process parameters, predicting performance outcomes, and enabling real-time monitoring. This paper aims to provide an overview of the recent applications of ML in the 3D and 4D printing of polymer composites. By highlighting the intersection of these technologies, this paper seeks to identify existing trends and challenges, and outline future directions.

Densifying Conduction Networks of Vertically Aligned Carbon Fiber Arrays with Secondary Graphene Networks for Highly Thermally Conductive Polymer Composites

AbstractThermally conductive polymer composites hold great potential for thermal management applications in the electronics industry, but achieving metal‐like thermal conductivity (>200 W m−1 K−1) remains challenging due to the inevitable phonon scattering and the thermal resistance at filler‐filler and filler‐matrix interfaces. Herein, an efficient approach is presented to overcome this long‐standing barrier by designing a densified interconnecting filler framework, featuring a macro‐level carbon fiber (CF) array welded with a high‐quality, self‐assembled graphene network. In this framework, vertically aligned continuous CFs function as primary through‐plane thermal conduction paths, minimizing phonon scattering and thermal resistance. Meanwhile, the secondary graphene network interconnects the CFs into a more integrated and densified framework while introducing supplementary thermal conduction paths. Following polymer backfilling, the resulting epoxy nanocomposite exhibits an unprecedented through‐plane thermal conductivity of 262 W m−1 K−1 at a filler loading of 23.3 vol%, establishing a new benchmark among the thermally conducting polymer composites. When employed as a thermal interface material, this composite offers a 68.2% enhancement in cooling efficiency compared to standard commercial counterparts. Furthermore, the functional composite presents excellent Joule heating and interfacial adhesion properties, making it promising for thermal interface healing and multifunctional thermal management applications in complex environments.

Baseline-free assisted lamb wave-based damage detection in CFRP composites using graph convolutional networks and Transformer models

Carbon fiber-reinforced polymer (CFRP) composites are widely used in aerospace but are susceptible to damage, threatening structural safety. Thus, developing an effective structural health monitoring system is essential. This study presents CFRP-former, a novel deep learning framework that detects damage in CFRP composites by constructing spatio-temporal representation graphs of Lamb waves (LWs). The CFRP-former comprises three key modules: graph convolutional neural network (GCNN), a multi-layer perceptron (MLP), and a Transformer Encoder. The GCNN models the topological relationships between LW nodes and sensors. The MLP reduces data dimensionality while preserving key information for subsequent analysis. Meanwhile, the Transformer Encoder, employing multi-head attention mechanisms, captures global time-series patterns in the LW signals. Additionally, the CFRP-former framework includes a parallel module that separately predicts both the size and location of damage. Experiments using only four sensors show that CFRP-former achieves high accuracy in detecting and quantifying damage, with robustness confirmed through ablation tests.

Improved composite network via bismuth iodide for efficient ice-nucleating application

The urgent demand for electricity requires more safe energy transportation. AgI-based weather modification agents are commonly employed to facilitate ice nucleation and remove the undesirable glaze icing to suppress the negative effects of natural disasters. However, the intrinsic nucleation potency of AgI strictly limits its further improvement. Here, a hexagonal BiI3 was added in AgI-based agents. The chemical interactions of BiI3 and precursors optimize the crystallization of the polymer composite, leading to an oriented composite network. In addition, BiI3 could alter the structure and morphology of the combustion products, therefore creating more possible heterogeneous nuclei sites. The resultant BiI3-modified AgI-based weather modification agent exhibits an ice nucleation ∼ 1014, which is nearly ten times higher than the sample without AgI-BiI3, leading to a 71.21 % enhancement of deicing efficiency compared to AgI sample. Our results indicate the effectiveness of BiI3 dopant to improve both nucleation and deicing performance for weather modification applications.

Improved tribological properties of MXene nanosheet filler-modified PPO composites

MXenes, a class of two-dimensional (2D) nanomaterials, exhibit exceptional properties such as outstanding mechanical and thermal stability, along with diverse surface characteristics, making them highly promising in the tribology. However, their tendency to aggregate within the polymeric matrix adversely affects the tribological performance of the polymer. In this study, glass fiber (GF) surfaces were modified with polydopamine (PDA), allowing smaller MXene nanosheets to adhere to the GF surface, whereas the larger MXene nanosheets were dispersed throughout the matrix. This approach effectively enhanced the dispersion of MXene nanosheets in the polymeric matrix, facilitating the preparation of polyphenylene oxide (PPO)/MXene composite materials. Compared with the pure PPO sample, the results showed that the average friction coefficient and wear rate of the PPO/MXene composites were reduced by 46.25% and 98.34%, respectively, due to the distinct roles of different MXene nanosheet sizes in the polymeric matrix. Furthermore, a uniform lubricating film was formed during the friction of the polymer composite, enhancing its tribological performance. This study proposes a novel design strategy to enhance MXene nanosheet dispersion and optimize their lubricating properties.

Tunable negative permittivity behavior and excellent electromagnetic shielding performance of pyrolytic carbon‐glass fiber felt/epoxy resin metacomposites

AbstractEffective and accurate adjustment of negative permittivity behavior is worthy of further investigation. Herein, pyrolytic carbon‐glass fiber felt/epoxy resin (PyC‐GFF/ER) metacomposites with tunable negative permittivity were prepared using an impregnation‐calcination method. The permittivity, electrical conductivity, and electromagnetic shielding performance of the polymer metacomposites were investigated. Due to the inherent three‐dimensional structural network of GFF, the PyC adhering to the surface of glass fiber easily formed a conductive network in the composites. As the PyC content increased in the ER composites, the conductivity mechanism changed from hopping conduction to metal‐like conduction. The ER composites with high PyC contents showed negative permittivity behavior and the epsilon‐near‐zero response owing to the low frequency plasma state of free electrons in the PyC‐conduction network. By controlling the PyC content, the negative permittivity behavior of ER composites could be effectively tuned. With the increase in PyC content, the values of negative permittivity increased, and the epsilon‐near‐zero frequency shifted to a higher frequency. Moreover, the ER composites with high PyC contents showed excellent electromagnetic shielding properties (29.4 dB) at X‐band. This work not only provided a feasible method to realize the tunable negative permittivity of polymer metacomposites, but also promoted its application in the microwave field.Highlights The pyrolytic carbon‐glass fiber felt/epoxy resin composites were fabricated. The negative permittivity was first reported in the PyC‐GFF/ER composites. Tunable negative permittivity could be well explained by Drude model. The polymer composites had excellent electromagnetic shielding property.

Natural-Fiber-Reinforced Polymer Composites for Furniture Applications.

Increasing environmental awareness has driven a shift in furniture production from traditional materials, such as wood and wood-based panels, to sustainable and environmentally friendly alternatives, such as natural-fiber-reinforced (NFR) composites. Environmental consciousness has become a key factor in both production and consumer choices, with growing demand for sustainably sourced materials, eco-friendly manufacturing processes, and durable furniture that helps reduce the impact of disposable products on the environment. This paper analyzes various requirements for natural-fiber-reinforced polymer composites used in furniture applications, including performance, structural-functional, ecological, economical, and safety requirements. It discusses factors influencing the performance of composite materials, such as the selection of matrix and reinforcing fibers, the matrix-to-reinforcement ratio, and the choice of manufacturing technology, as well as the compatibility and bonding between the matrix and fibers. Additionally, several standards commonly used to determine the mechanical, physical, and chemical properties of these materials are presented.

Strength Retention of Carbon Fiber/Epoxy Vitrimer Composite Material for Primary Structures: Towards Recyclable and Reusable Carbon Fiber Composites

Recently, the growth of the recyclability of carbon fiber reinforced polymer (CFRP) composites has been driven by environmental and circular economic aspects. The main aim of this research work is to investigate the strength retention of a bio-based vitrimer composite reinforced with carbon fibers, which offers both recyclability and material reusability. The composite formulation consisted of an epoxy resin composed of diglycidyl ether of bioshpenol A (DGEBA) combined with tricarboxylic acid (citric acid, CA) and cardanol, which was then reinforced with carbon fibers to enhance its performance. Differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy were performed to analyze the chemical composition and curing behavior of the vitrimer. Mechanical testing under tensile loading at room temperature was carried out on epoxy, vitrimer, and associated carbon fiber reinforced composite materials. The results demonstrated that the DGEBA/CA/cardanol vitrimer exhibited thermomechanical properties comparable to those of an epoxy cured with petroleum-based curing agents. It was observed that the maximum tensile strength of vitrimer is about 50 MPa, which is very close to the range of epoxy resins cured with petroleum-based curing agents. Notably, the ability of the vitrimer composite to be effectively dissolved in a dimethylformamide (DMF) solvent is a significant advantage, as it enables the recovery of the fibers. The recovered carbon fiber retained comparable tensile strength to that of the fresh carbon composites. More than 95% strength was retained after the first recovery, which confirms the use of fibers for primary and secondary applications. These research results open up new avenues for efficient recycling and contribute to the overall sustainability of the composite material at an economic level.

Experimental investigation of snake grass filler reinforced polymer composite

Experimental investigation of snake grass filler reinforced polymer composite

A validated simulation methodology for determining single lap shear allowable strength in thermoplastic polymer composites

While several modeling approaches exist to simulate the strength of single lap shear configurations, their application to obtaining design allowables for thermoplastic composites remains underexplored. This paper addresses this gap by presenting a novel methodology for the forward propagation of parameter uncertainty using advanced finite element models specifically tailored for thermoplastic carbon fiber composites. The proposed approach goes beyond traditional methods by integrating advanced damage models and a structured validation process, supported by an extensive experimental test campaign.We demonstrate the feasibility of determining design allowables through simulation by examining the influence of batch size on both the validation process and the prediction of allowable strength. Our findings provide new insights into the propagation of uncertainties in the context of composite material design, showing that it is possible to achieve reliable design allowables through simulation, which can significantly accelerate the development of new components while maintaining high safety standards.

Microplastic characteristics in rain/snow sampled from two northern Chinese cities

Atmospheric precipitation is recognized as a significant source of environmental microplastics, especially in inland waters and remote areas. However, due to the limited availability of existing data, further information on microplastics in precipitation is essential. Therefore, this study aims to elucidate the contamination of microplastics in both snowfall and rainfall while identifying potential factors that may influence their presence during atmospheric deposition. Samples of snowfall and rainfall were collected from two representative cities in Northern China across winter and summer seasons. Subsequently, microplastics were identified and quantified automatically using laser-assisted direct infrared imaging techniques. The findings indicate that microplastic concentrations are higher in snowfall (City A: 182.30 ± 190.25 items/L; City B: 301.74 ± 325.81 items/L) compared to rainfall (City A: 58.90 ± 51.00 items/L; City B: 39.20 ± 30.31 items/L), revealing significant variations in the polymer composition of microplastics. Moreover, a greater diversity of polymers was identified in snowfall relative to rainfall, despite some commonalities among polymers; fragments measuring between 20 μm to 100 μm comprised the majority of detected microplastic particles across both types of precipitation. Crucially, the frequency of precipitation events (rainfall versus snowfall) appears to affect the concentration of atmospheric microplastics, resulting in notably higher levels within snowfalls. These findings offer valuable insights into wet deposition processes by underscoring the atmospheric origins contributing to environmental microplastic pollution.

Enhancing mechanical performance of kenaf fiber reinforced polymer composites: influence of fiber characteristics and processing techniques

Enhancing mechanical performance of kenaf fiber reinforced polymer composites: influence of fiber characteristics and processing techniques

PVDF/PVB composite polymer electrolyte membranes with high conductivity and excellent cycling performance for lithium‐ion batteries

<scp>PVDF</scp>/<scp>PVB</scp> composite polymer electrolyte membranes with high conductivity and excellent cycling performance for lithium‐ion batteries

Optimization of high performance hybrid composite under ballistic test and performance of the hybrid composite under IED blast

Abstract In this investigation a novel material has been developed comprising of Silicon Carbide (ceramic), Aluminium honeycomb (metal) and Poly Ether Ketone (PEK)—Poly Phynelene Benzobisoxaole (PBO) fiber based blast proof composite. The experimental results proved that this polymeric composite is highly suitable for 9 mm pistol bullet with 430 m s−1 at distance of 5 m as well as for improvised explosive devices blast to absorb the sharpnels/splinters. This investigation also highlights an efficient back layer for a blast-proof sandwich composite. Layer optimization was carried out by finite element method (FEM) analysis of blast effect on the multi-layer polymer composite panel by ANSYS Explicit Dynamics (LS DYNA Solver). The resultant optimal layers of PEK-PBO composites then tested to validate results of FEM analysis. Experimentally it is proved that polymeric composite with 10 layers of PBO fabric when test fired under 9 mm pistol bullet with 430 m s–1 at distance of 5 m, the bullet penetrates, however, when the polymeric composite is made with a total of 20 layers of PEK-PBO fabric, all the test fired bullets are stopped. Therefore, under SNANAG 4569 blast test, the polymeric composite was essentially made with 20 layers of PBO fabric and it is experimentally proved that PEK-PBO composite is highly efficient as the back layer of hybrid composite and all the sharpnels of IED blast are completely absorbed.

Machining-Induced Burr Suppression in Edge Trimming of Carbon Fibre-Reinforced Polymer (CFRP) Composites by Tool Tilting

Several challenges arise during edge trimming of carbon fibre-reinforced polymer (CFRP) composites, such as the formation of machining-induced burrs and delamination. In a recent development, appropriate-quality geometric features in CFRPs can be machined using special cutting tools and optimised machining parameters. However, these suitable technologies quickly become inappropriate due to the accelerated tool wear. Therefore, the main aim of our research was to find a novel solution for maintaining the machined edge quality even if the tool condition changed significantly. We developed a novel mechanical edge-trimming technology inspired by wobble milling, i.e., the composite plate compression is governed by the proper tool tilting. The effectiveness of the novel technology was tested through mechanical machining experiments and compared with that of conventional edge-trimming technology. Furthermore, the influences of the tool tilting angle and the permanent chamfer size on the burr characteristics were also investigated. A one-fluted solid carbide end mill with a helix angle of 0° was applied for the experiments. The machined edges were examined trough stereomicroscopy and scanning electron microscopy. The images were evaluated through digital image processing. Our results show that multi-axis edge-trimming technology produces less extensive machining-induced burrs than conventional edge trimming by an average of 50%. Furthermore, we found that the tool tilting angle has a significant impact on burr size, while permanent chamfer does not influence it. These findings suggest that multi-axis edge trimming offers a strong alternative to conventional methods, especially when using end-of-life cutting tools, and highlight the importance of selecting the optimal tool tilting angle to minimize machining-induced burrs.

An Innovative Biphasic Reaction System for Highly Selective Benzene Hydroxylation based on Photocatalytic Polymer Composites

AbstractThe hydroxylation of benzene to phenol in presence of hydrogen peroxide was performed using a new biphasic system consisting of a solid phase, a photocatalytically active monolithic polymer composite, immersed in an aqueous phase in which H2O2 is dissolved. In detail, ZnO photocatalytic particles were embedded into the hydrophobic syndiotactic polystyrene (sPS) polymer. Zinc oxide nanostructures (ZnO NSs) were synthesized by an electrochemical procedure. The surface morphology and structure of ZnO nanoparticles and ZnO‐sPS monolithic aerogel composite (ZnO/sPS) were investigated by scanning electron microscopy, X‐ray diffraction and X‐ray photoelectron spectroscopy analysis. Photocatalytic results evidenced that, under UV irradiation, both ZnO NSs and biphasic system water‐photocatalytic composites had a high benzene oxidative property but with very low phenol yield (&lt;2 %) at pH=7. To enhance the phenol selective formation, the pH of the aqueous solution surrounding the photocatalytic polymer composite was modified. A phenol yield of about 94 % and benzene conversion higher than 99 % was obtained in alkaline conditions (pH=11).

Internal shear damage evolution of CFRP laminates ranging from −100 °C to 100 °C using in-situ X-ray computed tomography

Carbon Fiber Reinforced Polymer (CFRP) composites have been widely used in aerospace due to their high specific stiffness, strength, and fatigue properties. However, the ambient temperature significantly influences CFRP's mechanical properties and damage evolution, deriving from the temperature effect on the microstructural behavior and the mesoscopic damage evolution. In this study, the temperature-dependent in-plane shear failure behavior of CFRP composites was investigated. In-situ X-ray Computed tomography (CT) tensile experiments of laminates ([45°/-45°]2s) at RT, −100 °C, and 100 °C were carried out to study the in-plane shear failure mechanisms. The 3D fracture morphology was extracted with internal damage evolution process estimated and quantified. The in-situ 3D deformation fields of critical regions were acquired using the Digital Volume Correlation (DVC) method. The effect of temperature on strain field and the correlation between the high-strain region and the fracture location were analyzed. The results revealed the temperature correlations and failure mechanisms of CFRP's mechanical characteristics and internal damage evolution process. Compared to room temperature (RT), the delamination damage area of the sample increased by 80 % at 100 °C. Meanwhile, the shear modulus of CFRP decreases by 78.4 % from −100 °C to 100 °C, and the fracture strain increases by 95 % from RT to 100 °C. The DVC results indicated a dispersion of high-strain regions at −100 °C, reflecting the brittle damage characteristics, while an extensive ductile deformation region was captured at 100 °C. Fiber-matrix debonding is the dominant failure mode of composites under shear loading, whereas significant matrix cracking was observed at −100 °C and partial fiber pullout occurred at 100 °C.