Properties Of Polymer Composites Research Articles

Thermorheological complexity in Nylon12‐Cork composites: Role of interfacial compatibilizer

AbstractHerein, we demonstrate how compatibilizers affect the thermorheological properties and morphology of engineering thermoplastic composites based on nylon and cork. Nylon12 was melt‐mixed with cork treated with four distinct compatibilizers with radically different chemical structures and compositions, respectively: (i) Octadecanamide (ODA), (ii) polyethylene‐graft‐maleic anhydride (PE‐g‐MA), (iii) polypropylene‐graft‐maleic anhydride (PP‐g‐MA), and (iv) (3‐aminopropyl)triethoxysilane (APTS). The rheological behavior was assessed using an oscillatory rheometer and the morphology was visualized using a scanning electron microscope. The rheological data were thoroughly analyzed using different formalisms based on empirical, phenomenological, and molecular origin, including the Carreau‐model, time–temperature superposition (TTS), Han plot, and van Gurp–Palmen (vGP) plot. It is observed that rheological data of neat nylon can be treated as themorheologically simple. However, the inclusion of cork makes the composite thermorheologically complex and increases the relaxation time (τ) by >50‐fold when compared to the neat polymer. As compatibilizers, ODA and PP‐g‐MA significantly lower τ, improve internal flow behavior, and demonstrate good cork distribution and dispersion. However, PE‐g‐MA does not affect the τ of composites significantly. The application of APTS as a compatibilizer enhances the interfacial interaction between Nylon12 and cork most significantly, which leads to a notable rise in τ, and the composite's elastic modulus surges by two orders in magnitude compared to neat Nylon. Additionally, the polymer melt flow becomes elastically dominant. Finally, it is observed that the Han plot offers a better insight into the correlation between changes in the thermorheological behavior and the microstructural modifications to the composites.Highlights Utilizing cork particles as a sustainable raw material for engineering thermoplastics. Quantifying compatibilizer's impact on rheological properties of polymer composite. Illustrating how interfacial interaction affects thermorheological complexity in composites. Visualizing morphological change in nylon‐cork composite with interfacial interaction. Producing lightweight engineering polymer composites using cork as a filler.

The effect of lubrication on the tribological properties of polymer composites for high contact pressure hydropower bearings

Premature failure of polymeric self-lubricating bearings is a limiting factor in the sustainable and continued operation of hydropower plants. In this work, the tribological performance of two novel polymer composites was studied with respect to commercially available materials. The materials were evaluated under dry and lubricated conditions, using water and an environmentally adaptive lubricant (EAL). The two tested commercial materials yielded a low dry sliding friction and wear. Under water lubricated conditions, the in-house developed polyphenylene sulphide (PPS) based composite provided an exceptionally low friction and a wear rate of a factor of 3 lower than the best performing commercial material. Using the EAL wear was reduced for most materials by up to 85%.

Anomalous Conductive Properties of Polymer Composites with Carbon Nanotubes: Why Power Laws Are Not Universal

The conductive properties of CNT/polymer composites have been extensively studied. However, the impact of CNT distribution in the matrix on the composite polarization remains underexplored and poorly understood. Since it is difficult to achieve a uniform distribution of CNTs in polymers, most researchers have focused only on indiscriminately aggregated states. In this article, a new blending method was suggested to prepare a series of epoxy resin-based composite samples with varying levels of CNT uniformity/aggregation and the same filling fractions. Notably, the permittivity values turned out to be inversely related to the composite uniformity: the lowest permittivity values were obtained in the most uniform formulation, and vice versa. With 0.1% CNT, the real part values of the most uniform and aggregated samples were 6.6 and 16.2 at 107 Hz and 11.6 and 370.5 at 101 Hz, respectively. For the filler content of 0.1–0.5%, the conductive properties were largely determined by the distribution of CNTs and not their content. Within the entire frequency range, the uniform sample with 0.2% CNT exhibited significantly lower permittivity than the aggregated sample with 0.1% CNT. These findings emphasize the importance of the aggregation factor and underscore the non-universality and limitations of the percolation theory and power laws. The observed phenomenon is best explained by the micro-capacitor model, or the Maxwell–Wagner polarization, and suggests that a significant portion of the literature in the field needs to be reconsidered.

Advancements in chemical modifications using NaOH to explore the chemical, mechanical and thermal properties of natural fiber polymer composites (NFPC)

Abstract Increasing environmental awareness and concerns about global warming have resulted in a significant demand for sustainable and eco-friendly resources, such as naturally available fibers, that can be suitable alternatives to petroleum/synthetic materials such as glass, carbon and Kevlar in reinforced composites. The exploration of natural fibers as reinforcements in composites is increasing in popularity, particularly in the development of transport and household components. However, natural fibers also have a few limitations that should be addressed appropriately, including lack of compatibility between fiber-matrix, fiber swelling, excess absorption of moisture, resistance to chemicals and fire. Consequently, various processes have been used to improve the fiber surface, to obtain a better fiber–matrix interface. The primary objective of this work is to review the impact that a 5 % NaOH (sodium hydroxide) treatment has on the chemical, mechanical, and thermal properties of natural fiber-reinforced composites (NFRC).

Probing the microstructural properties of metal-reinforced polymer composites

Abstract Microstructural analysis is an important technique to study the extent of interaction between metal fillers and polymers. The aim of this study is to review the investigations on the microstructural properties of metal-reinforced polymer composites. Scanning Electron Microscope (SEM) operating at a magnification range of 2,500× is typically used for examining the microstructure of the composites. Microstructural analysis reveals two key qualitative informations, dispersion and interfacial adhesion. It was observed from the review that flaky metal fillers will maximise dispersion and interfacial adhesion hence leading to improved mechanical, tribological, electrical, and thermal properties of the composites. Utilizing ternary metallic components helps to eliminate aggregation because the cohesion of metal particles is limited. It is important that future microstructural studies evaluate nano-sized fillers as compared to micro-sized ones. Also, it is important to quantitatively correlate the arrangement of the fillers to macro-scale properties and finite element analysis is an important tool that can help achieving this.

Numerical modeling of fiber orientation in multi-layer, isothermal material-extrusion big area additive manufacturing

Fiber orientation is a critical factor in determining the mechanical, electrical, and thermal properties of 3D-printed short-fiber polymer composites. However, the current numerical studies on predicting fiber orientation are limited to straight single-strand configurations, while the actual printed parts are often composed of complex multi-layer structures. To address this issue, we conducted numerical simulations of material extrusion in multi-layer big-area additive manufacturing without any post-deposition strand morphology modification mechanism. By examining the effects of material properties and printing conditions when extruding and depositing strands on a fixed substrate as well as previously deposited layers, it was possible to observe the complex interplay between multiple layers and its impact on fiber orientation. The work and methodology presented in this paper can be used to identify optimal extrusion-to-nozzle speed ratios, material rheology, fiber content, and fiber aspect ratio to achieve the desired performance and thermo/mechanical properties of additively manufactured parts. This work is an important contribution towards the manufacture of high-performance, short-fiber polymer composites as the presented methodology can enable engineers to precisely predict and tailor the fiber orientation in 3D printed parts.

Vat photopolymerization of polymer composites with printing-direction-independent properties

The implementation of additive manufacturing techniques for thermal management applications necessitates the development of printable materials with enhanced properties. This study focuses on enhancing the thermal and mechanical properties of 3D-printed polymer composites (UV-based vat photopolymerization; VPP), starting by loading graphene nanoplatelets (GNP) as fillers into a monomer solution. GNP stabilization in the solution is achieved via the addition of sepiolite, a fiber-like clay, that traps them in dispersion. However, the inherent GNP-UV blocking limits its concentration in the VPP-printed composite, and its 2D nature yields parts with undesired anisotropic properties. We overcome this GNP concentration limit by using the excluded volume approach, namely, adding micron-sized diamonds to increase the GNP effective concentration. This approach also transforms the anisotropic VPP-printed composite into an isotropic structure, ensuring consistent thermal and mechanical enhancement regardless of the printing direction. Thermal conductivity (TC) and fracture toughness (FT) are enhanced by 180 % and 100 %, respectively (vs. the neat polymer). However, the electrical conductivity (EC) is also enhanced, which is undesirable in thermal management systems (risk of short-circuiting). Therefore, hexagonal boron nitride is added to reduce the EC, producing composites with enhanced TC and 140 % FT enhancement. Our approach holds promise for various applications, especially in advanced heat management solutions, where enhanced TC, light weight, and low EC are imperative.

The Study of Composite Materials Properties Based on Polymers and Nano-Additives from Industrial Wastes from Kazakhstan.

This research is aimed at studying the properties of polymer anticorrosion coatings based on ED-20 resin widely used in practice and industrial wastes. In this work, three basic types of nanoscale nanofillers were chosen: dispersed particles-microsilica, microspheres obtained at Kazakh enterprises, and carbon nanotubes. Physicochemical research methods were used in the research: a laser analyzer for studying the dispersibility of industrial waste and spectrometric research methods. The properties of materials were investigated by standardized methods. The obtained results show that the introduction of microsilica and microspheres obtained at Kazakhstani enterprises, used as additives, improves both the physical and mechanical properties of epoxy composites compared to the standard (control) material. The results of experiments have shown that the optimal content of additives of microsilica and microspheres provides an improvement in the physical and mechanical properties of epoxy composites in comparison with the standard (control) material. Studies have shown that the introduction of microspheres into ED-20 polymer increases impact toughness. The introduction of microsilica into the matrix contributes to the increase of elastic modulus. Experimental studies of optical properties of samples of carbon composite polymer films based on polystyrene (PS) with additives of carbon nanotubes C60 and C70 and multilayer carbon nanotubes were also carried out. The experimental results obtained for the optical properties of polymer composites based on basic polymers from solid waste and carbon nanotubes showed that the optical properties of polymer composites undergo noticeable changes.

Advanced polymer composites and polymer hybrids for cartilage tissue engineering

AbstractThe repair and regeneration of cartilage is a challenge for scientists and clinical surgery. Achieving cell adhesion and regeneration, anti‐inflammatory, lubrication, targeted drug delivery and controlled release simultaneously in cartilage treatment are the goals of researchers. Polymer composites and hybrids have the potential to realize above functions in cartilage tissue engineering. This review refers to cartilage injuries, current clinical techniques, and their benefits and limitations, focusing on the most relevant and state of art of advanced polymers for cartilage tissue engineering. The frontier applications of multifunctional polymer composites and hybrids in cartilage tissue engineering are discussed in depth, including polymer scaffold, polymer bio‐lubricant, and zwitterionic polymer for drug delivery and sustained drug release. A summary of comprehensive properties of polymers such as processability, mechanical properties, biocompatibility, biodegradability, hydrophilicity, cytotoxicity, etc., and their mechanisms are analyzed. Furthermore, some key challenges and outstanding concerns on polymer‐based materials for cartilage tissue engineering are presented followed by future perspectives.Highlights The state of art of advanced polymers for cartilage tissue engineering. The advanced bionic property and mechanism of polymer composites and hybrids. Polymers for scaffold, biolubricant, drug delivery, sustained drug release. Future perspectives on polymer composites, hybrids‐based cartilage materials.

Comparison of Mechanical Property Simulations with Results of Limited Flexural Tests of Different Multi-Layer Carbon Fiber-Reinforced Polymer Composites.

This article is focused on the experimental study of flexural properties in different multi-layer carbon fiber-reinforced polymer (CFRP) composites and correlations with the results of finite element method (FEM) simulations of mechanical properties. The comparison of the results shows the possibility of reducing the number of experimental specimens for testing. The experimental study of flexural properties for four types of carbon fiber-reinforced polymer matrix composites with twill weaves (2 × 2) was carried out. As input materials, pre-impregnated carbon laminate GG 204 T and GG 630 T (prepreg) and two types of carbon fiber fabrics (GG 285 T and GG 300 T (fabric)) were used. Multi-layer samples were manufactured from two types of prepregs and two types of fabrics, which were hand-impregnated during sample preparation. The layers were stacked using same orientation. All specimens for flexural test were cut with the longer side in the weft direction. Pre-impregnated carbon laminates were further impregnated with resin DT 121H. Carbon fabrics were hand-impregnated with epoxy matrix LG 120 and hardener HG 700. To fulfill the aim of this research, finite element method (FEM)-based simulations of mechanical properties were performed. The FEM simulations and analysis were conducted in Hexagon's MSC Marc Mentat 2022.3 and Digimat 2022.4 software. This paper presents the results of actual experimental bending tests and the results of simulations of bending tests for different composite materials (mentioned previously). We created material models for simulations based on two methods-MF (Mean Field) and FE (Finite Element), and the comparative results show better agreement with the MF model. The composites (GG 285 T and GG 300 T) showed better flexural results than composites made from pre-impregnated carbon laminates (GG 204 T and GG 630 T). The difference in results for the hand-impregnated laminates was about 15% higher than for prepregs, but this is still within an acceptable tolerance as per the reported literature. The highest percentage difference of 14.25% between the simulation and the real experiment was found for the software tool Digimat FE 2022.4-GG 630 T composite. The lowest difference of 0.5% was found for the software tool Digimat MF 2022.4-GG 204 T composite. By comparing the results of the software tools with the results of the experimental measurements, it was found that the Digimat MF 2022.4 tool is closer to the results of the experimental measurements than the Digimat FE 2022.4 tool.

Nano‐enhanced epoxy sandwich composites: Investigating mechanical properties for future aircraft construction

AbstractThe aviation sector is continually seeking ways to reduce the weight of aircraft structures without compromising their mechanical integrity. Lightweight materials, such as advanced epoxy sandwich composites with hybrid nanostructures, have the potential to significantly contribute to fuel efficiency, thereby addressing environmental concerns and operational costs. This research investigates the mechanical properties of hybrid sandwich polymer composites filled with silica nanoparticles (SNiPs). Epoxy isocyanate (PU) foam sandwich composites were fabricated with kevlar fiber, carbon fiber, and glass fiber, constructed by alternating inclined interply bidirectional fiber and foam layers. SNiPs were introduced into the composite system at varying percentages, such as 0, 2, 4, and 6 wt%. The study employs a systematic approach, incorporating experimental testing, to assess key mechanical parameters, including tensile strength, flexural strength, and shear strength. The test results indicate that the incorporation of SNiPs improved the mechanical properties of the composites, leading to enhanced strength, toughness, and modulus of elasticity. Incorporation of composite laminates with 4 wt% SiNPs resulted in improved three‐point bending, tensile, shear, and torsional strengths, with maximum values of ca. 64, ca. 5, ca. 2 MPa, and ca. 22 Nm, respectively. The findings contribute to the ongoing pursuit of materials that can meet the stringent demands of modern aviation, ultimately paving the way for advancements in aircraft construction and design.

The Effect of Self-Healing Microcapsules in Corrosion Testing on Magnesium AZ31 Alloy and Fibre Metal Laminates

Fibre metal laminates (FMLs) are the most interesting composite materials of the past decade. They possess the properties of both polymer composites and metallic alloys. However, there is a problem with corrosion when the outer layers are made of aluminium or magnesium. The electrochemical changes that occur during the corrosion process and the mechanisms associated with the corrosion phenomenon are still being investigated. Recently, self-healing phenomena have emerged as a useful approach to prevent corrosion. However, there is limited research on the combination of FMLs and self-healing layers. Therefore, the main purpose of this article is to evaluate the self-healing ability of a magnesium/PEO layer based on microcapsules in a corrosion environment. It was observed that the corrosion mechanism in magnesium alloys is very complex. However, the use of a barrier layer with PEO treatment and microcapsules yielded positive anti-corrosion results. The FML samples were subjected to a 6-week corrosion test, and the addition of microcapsules to the layers showed positive results. In contrast, the samples without microcapsules exhibited intergranular corrosion. In the future, comprehensive tests using self-healing microcapsules in FMLs could greatly enhance their anti-corrosion properties and improve the integrity of the structure.

Modeling of mechanical properties of wood-polymer composites with Artificial Neural Networks

Mechanical properties (tensile strength (TS), modulus of elasticity in tensile (MET), flexural strength (FS), modulus of elasticity (MOE)) of the material to be obtained depending on the production parameters in the production of high-density polyethylene (HDPE) wood-polymer composites with Scots pine wood flour additive were predicted using Artificial Neural Networks (ANN) model and without destructive testing. In the first stage of the study, an ANN model was developed using data from 56 different studies in the literature on the mechanical properties of wood polymer composites. In the second stage, in order to determine the reliability of the model, output values were estimated using input parameters that had not been used in training and testing of the model. Based on the same input parameters, test specimens were produced and mechanical tests were performed. The results obtained from the experiments and ANN model were compared by considering the mean absolute percentage error (MAPE) value. The coefficient of determination (R2) values obtained in the training and testing phase of the ANN models were all higher than 0.90. In this way, the mechanical properties of the wood polymer composite were successfully predicted by the ANN model. Because most of the MAPE values obtained from the mechanical tests were below 10%, the model was considered a reliable model.

Tribological performance of functional coated fiber reinforced additively manufactured polymer composite

Additive manufacturing has witnessed an upward trend in utilization across diverse industries in recent years. This study examines the tribological properties of polymer composites produced using additive manufacturing. The polymer composites were produced using the fusion deposition modeling process. Subsequently, they undergo thermal spray coating and spin coating processes that deposit hafnium carbide particles onto their surface. The wear test studies were conducted at three distinct temperature levels in accordance with the ASTM standard procedure. The findings demonstrated that the application of a ceramic particle coating led to a substantial decrease in the specific wear rates. Additionally, there were observed differences in the wear rates depending on the specific methods used for applying the coating. The application of thermal coating shown high efficacy in reducing wear rates and safeguarding the underlying materials against material loss. The uncoated carbon fiber reinforced polylactic acid (PLA-CF) material showed a slightly significant amount of material degradation as the test chamber temperature increased, in comparison to the coated specimens. The average specific wear rate of the thermally coated carbon fiber reinforced polylactic acid specimen at a temperature of 70 °C is 0.000156 kg Nm−1.

3D-Networks Based Polymer Composites for Multifunctional Thermal Management and Electromagnetic Protection: A Mini Review

3D-Networks Based Polymer Composites for Multifunctional Thermal Management and Electromagnetic Protection: A Mini Review

Study on Mechanical Properties of Polymer Composites Filled with Nano Egg-shell Powder

Polymeric materials, when reinforced with synthetic fibers like glass, carbon, and aramid, offer notable advantages including increased stiffness and strength-to-weight ratio compared to conventional materials such as wood, concrete, and steel. Among these options, glass fiber stands out due to its affordability and widespread availability. Glass fiber reinforced polymer composites exhibit moderate mechanical properties, which can be significantly enhanced by incorporating nano fillers like eggshell powder. This study explores the utilization of nano eggshell powder as well as methods for effectively integrating nano fillers into polymer composites to create value-added products. Four types of composites, varying in weight proportions of nano eggshell powders, were prepared using the hand lay-up technique for mechanical and thermal characterizations. Various mechanical properties including tensile strength, flexural strength, impact behavior, as well as thermal properties via TGA and DMA analysis were investigated. The results indicate that incorporating the optimal amount of nano fillers significantly improves the overall strength of glass fiber reinforced composite materials, leading to cost savings of over 30%. This suggests that nano eggshell fillers hold great potential in composite manufacturing, particularly for substituting high-cost glass fibers in low load-bearing applications.

Unveiling the Influential Factors and Heavy Industrial Applications of Graphene Hybrid Polymer Composites

Graphene hybrid-filler polymer composites have emerged as prominent materials that revolutionize heavy industries. This review paper encapsulates an in-depth analysis of different influential factors, such as filler/graphene type, aspect ratios, dispersion methods, filler-matrix compatibility, fiber orientation, synergistic effects, different processing techniques, and post-curing conditions, which affect the processing and properties of graphene hybrid polymer composites, as well as their resultant applications. Additionally, it discusses the substantial role of graphene reinforcement with other fillers, such as carbon nanotubes, silica, nano-clays, and metal oxides, to produce functionalized hybrid polymer composites with synergistically enhanced tailored properties, offering solutions for heavy industries, including aerospace, automotive, electronics, and energy harvesting. This review concludes with some suggestions and an outlook on the future of these composite materials by emphasizing the need for continued research to fully optimize their potential.

Highly enhanced microwave absorption of carbon nanotube/nickel/styrene-butadiene-styrene composite with segregated structure

High-performance microwave absorption (MA) polymer composites are highly required in electromagnetic protection. Although the desirable MA performance of many MA absorbers is obtained, its loading of obtaining optimal MA performance still is too high, which is not beneficial to the mechanical properties of polymer composites. In this work, based on the concept of segregated structure, the selective distribution of carbon nanotube/nickel (CNT/Ni) particles was successfully achieved in the styrene-butadiene-styrene (SBS) matrix via hot-compression molding. The CNT/Ni/SBS composites with segregated structure present an excellent MA performance when the filler content is only 5 wt%, including the minimum reflection loss (RLmin) of −42.7 dB and effective absorption bandwidth (EAB) of 6.6 GHz, which shows 27.3 % and 8.2 % increases in comparison to the optimal MA performance of the composites with randomly dispersed structure (10 wt%). In addition, the elongation at break and tensile strength of CNT/Ni/SBS composites can reach 1222 % and 14.3 MPa, respectively, showing great application potential as flexible MA materials. The efficient method provides a promising way to improve the function efficiency of MA absorbers and develop high-performance MA polymer composites with low filler loading in the future.

Optimized random forest model for predicting flexural properties of sustainable composites

AbstractIn an era of technological advancements, the quest for sustainable products has taken a center stage. The utilization of natural fiber reinforced polymer composites has become crucial in the manufacturing of eco‐friendly products due to their low cost, renewability, biodegradability, and comparable properties to synthetic composites. Coir‐based composites have been utilized in roofing, composite panels, furniture, and bio‐based insulation applications, providing enhanced strength and sustainability. In the current investigation, an exploratory data analysis (EDA) was conducted to understand the relationship between the various input variables and the flexural properties of short coir polymer composites (SCPCs). The data analysis revealed that manufacturing process had a significant impact on the flexural properties of SCPCs. Based on the insights gained from the EDA, an optimized Random Forest prediction model was developed to predict the flexural properties. Genetic algorithm approach for hyperparameter optimization led to lower objective loss in contrast to Bayesian optimized Random Forest model. The model's performance was subsequently evaluated through holdout validation, and the outcome demonstrated the model's proficiency in accurately predicting the properties. The developed model can be used as a tool for optimizing the design of SCPCs for specific applications, by predicting the flexural properties of the composites.Highlights Flexural behavior of short coir polymer composites was analyzed and modeled. Manufacturing process has the highest impact on the flexural properties. Random forest model predicted the flexural properties with high accuracy. Genetic algorithm optimized model further enhanced the model performance. The developed framework provides insights into designing biocomposites.

Mechanical Bonding Properties of Solderable Anisotropic Polymer Composite containing Low-Melting-Point and High-Melting-Point Solder Fillers

In this papers, to enhance the mechanical bonding properties of solderable anisotropic polymer composites (SAPCs) containing low-melting-point solder filler only, a new low-melting-point solder and high-melting-point solder mixed filler filled SAPCs (LH-SAPCs) was proposed, and the influence of the high-melting-point solder filler on the conduction path formation and mechanical bonding properties of the LH-SAPC were investigated. Two types of LH-SAPC were synthesized by adding high-melting-point solder within the low-melting-point solder/high-melting-point solder mixed filler at mixing ratios of 0 and 50 vol% (the volume fraction of low-melting-point solder/high-melting-point solder mixed filler in the polymer composite was 20%), and a bonding test was conducted using QFP. The results exhibited that the LH-SAPC containing high-melting-point solder formed a wide and stable conduction path due to the proper selective conduction path formation behavior by the interaction between molten low-melting-point solder and solid-state high-melting-point solder fillers within the polymer composite with low viscosity condition. Furthermore, the mechanical bonding properties of the LH-SAPC joints containing high-melting-point solder were enhanced compared to that of LH-SAPC containing low-melting-point solder only owing to the precipitation hardening and dispersion strengthening effects due to the increase of fine Bi-rich, Cu<sub>6</sub>Sn<sub>5</sub>, and Ag<sub>3</sub>Sn intermetallic compound particles inside the conduction path.