Properties Of Composite Materials Research Articles

Study on the mechanical properties of layered gradient structure PBT-based flame retardant composite materials

Abstract To enhance the flame retardancy of Polybutylene Terephthalate (PBT) based composite materials and overcome the decrease in mechanical properties due to the high content of nano-antimony trioxide (nano-Sb2O3), this study initially applies a composite modification method to treat the surface of nano-Sb2O3. Subsequently, composite materials with a gradient distribution of nano-Sb2O3 are prepared through lamination hot-pressing technology, and their mechanical and flame retardant properties are investigated. The results show that the modifiers CTAB and KH560 are successfully grafted onto the surface of nano-Sb2O3, altering its surface properties. Through lamination hot-pressing technology, a gradient distribution from the surface to the core is achieved. Compared to the homogeneous distribution P666, G828 exhibits a 6% increase in Limiting Oxygen Index (LOI), improving the flame retardancy of the composite material. As nano-Sb2O3 enriches on the composite material's surface, the amount of char residue increases. The tensile strength, bending strength, and impact strength of G828 composite material increase by 19.7%, 37.1%, and 103%, respectively, compared to the homogeneous composite material P666, proving the significant effect of G828's gradient distribution in enhancing the mechanical properties of the composite material.

Analysis of Mechanical Properties and Thermal Conductivity of Thin-Ply Laminates in Ambient and Cryogenic Conditions

It is widely known that glass–epoxy laminates are renowned for their high stiffness, good thermal properties, and economic qualities. For this reason, composite materials find successful applications in various industrial sectors such as aerospace, astronautics, the storage sector, and energy. The aim of this study was to investigate the mechanical and thermal properties of composite materials comprising two different types of epoxy resin and three different hardeners, both at room temperature and under cryogenic conditions. The samples were produced at IZOERG (Gliwice, Poland) using a laboratory hot-hydraulic-press technique. During cyclic loading–unloading tests, degradation up to a strain level of 0.6% was observed both at room temperature (RT) and at 77 K. For a glass-reinforced composite with YDPN resin (EP_1_1), the highest degradation was recorded at 18.84% at RT and 33.63% at 77 K. We have also investigated the temperature dependence of thermal conductivity for all samples in a wide temperature range down to 5 K. The thermal conductivity was found to be low and had a relative difference of up to 20% among the composites. The experimental results indicated that composites under cryogenic conditions exhibited less damage and were stiffer. It was confirmed that the choice of hardener significantly influenced both properties.

Compare the Properties of Composite Material by Date Leaves with Different Additives

Almost no product is made today without the use of composite materials, which have demonstrated their value over time in a variety of applications. Examples include household products, automobiles, oil and gas stations and spacecraft. Instead of using timber, leaves will be used to create a solid material. The goal of this study is to identify the distinguishing features of composite materials made from dates palm waste, as well as the overall effects on the properties when changing the mixture's proportions and the amount to which those materials are vulnerable to outside influences. It also aims to identify the best material that can be produced and used in home furnishings, manufacturing, architectural design, practical applications, and other science-related fields. This project will address the use of natural fibers from dates palm waste and some other materials to convert them into a strong, lightweight, low-cost composite material to replace wood, aluminum, synthetic fibers, and other materials in industries and uses. It will also explore the manufacturing processes, testing methods, and the outcomes of comparing it with other materials. The UHU (adhesive) matrix has the lowest hardness value compared to others. Structure tests show composites' internal composition; it plays an important role in understanding the properties of composites. The water absorption test demonstrates the duration required for composites to become saturated with water, with optimal results falling within the range of 13 to 24 hours for saturation.

Evaluation into the effect of lignocellulosic biochar on the thermal properties of shape stable composite phase change materials

Biochar is suitable for preparing shape stable composite phase change materials (sscPCMs) due to the advantages of cost-effective, environmentally, and sustainability. However, the heat properties of biochar-based sscPCMs were not consistent. To investigate how different types of biochar influence the thermal properties of sscPCMs, three types of sscPCMs were successfully prepared using peanut shell biochar (PSC), poplar wood biochar (PWC), and corn straw biochar (CSC) as framework materials and combined with stearic acid (SA). A comprehensive analysis of the thermal properties of three sscPCMs was performed, taking into account thermal conductivity, phase change latent heat, encapsulation efficiency, crystallization rate, and energy storage efficiency. The study indicated that among the three types of sscPCMs, SA/PWC sscPCMs demonstrated excellent comprehensive performance. The phase change latent heat of SA/PWC reached 100.13 J/g, and the thermal conductivity was 0.38 W/mK. Compared to SA/PSC, the phase change latent heat of SA/PWC increased by 45.96 %, with only a 28.30 % reduction in thermal conductivity. In comparison to SA/CSC, the thermal conductivity of SA/PWC improved by 18.75 %, while the phase change latent heat decreased by only 14.02 %. In addition, the proportions of cellulose, hemicellulose, and lignin played a crucial role in determining the thermal properties of sscPCMs. This study clarified the mechanism by which biochar influences the thermal characteristic of sscPCMs, offering valuable insights for choosing biochar framework materials.

Syndiotactic polypropylene-based elastomer as promising toughening agent for waste appliances-derived polypropylene

The rapid replacement of household appliances has generated a significant amount of waste appliances-derived polypropylene (WAPP), presenting a valuable resource for recycling. However, the long-term use and subsequent thermal processing of WAPP lead to its degradation, significantly impairing its toughness. Herein, syndiotactic polypropylene (sPP) as a novel toughening agent was investigated to achieve the efficient toughing of WAPP. The incorporation of 15 wt% of the sPP-based elastomer increased the impact strength of WAPP to 29.2 kJ/m2 (25 °C), which was 5.7 times that of the unmodified one and 1.9 times that modified with polyolefin elastomers (POE). This inspiring effect originates from the structural similarity between isotactic and syndiotactic polypropylene, which not only achieves a more uniform dispersion of the rubbery phase, but also creates micro voids between the phases due to the incompatibility of sPP and iPP, making it easier for shear bands to form. Further, the contradiction between rigidity and toughness is reconciled by introduction of talcum powder. This comprehensive investigation into the effects of the sPP-based toughening agent on the composite material's properties expands the potential applications of sPP and enhances our understanding of its toughening mechanisms.

Influence of Al2O3 - nano filler on the Vachellia Nilotica blended hybrid epoxy composites: a comprehensive analysis of mechanical, viscoelastic, and dielectric behavior

This work presents the influence of Alumina (Al2O3) Nano powder on the mechanical, dynamic, and dielectric properties of the hybrid epoxy resin composite material containing Vachellia nilotica (VN). The hand lay up method was used to make the composite specimens at different volume fractions of the alumina nano particle filler (3, 6, 9, 12, and 15 v/v%). The Vachellia nilotica content was kept at 12 v/v% in all the samples remaining being epoxy resin. The experimental results indicate that the composite with 9 v/v% Al2O3 showed better mechanical and dielectric properties when compared to other volume percentages. The epoxy composite with the highest glass transition temperature and storage modulus was also the one containing 9 v/v% nano filler. Furthermore, the dielectric test demonstrated that the addition of the nano filler strengthened the dielectric strength of the composite. The structural morphology of the composite's tensile fracture was investigated using scanning electron microscopy (SEM) to investigate the interaction between the epoxy matrix and the fillers in the hybrid composites.

Glass-ceramic binder of cordierite composition for low-temperature sintering of high-strength ceramic materials based on oxygen-free silicon compounds

The mechanical properties of composite ceramic materials obtained based on oxygen-free silicon compounds are largely determined by the properties of the glass binder. This paper presents the results of studies aimed at determining the most fusible glass in the pseudo-binary system 2MgO2Al2O35SiO2–2MnO2Al2O35SiO2 with a high tendency to crystallize as a glass-ceramic binder for low-temperature sintering of high-strength ceramic materials based on oxygen-free silicon compounds. The crystallization tendency of the experimental melts decreases with an increase in in the content of manganese cordierite, as confirmed by X-ray and infrared spectroscopic studies. Based on experimental studies, a melting diagram was constructed, which was used to determine the ratio between magnesium cordierite and manganese cordierite (50:50 wt.%), ensuring a minimum melt temperature of 12750C. The melting point of the glass of the specified composition is 14500C. The synthesized glass is characterized by a softening point of 8000C and crystallizes intensively at 10300C. The The thermal coefficient of linear expansion of the crystallized glass samples is 20.810–7 0C–1. X-ray diffraction and electron microscopic studies have shown that the developed glass is almost completely crystallized during heat treatment for 2 hours, forming a cordierite solid solution 2(Mg,Mn)O2Al2O35SiO2. The size of the cordierite phase crystals ranges from 0.5 to 3.0 m. Due to its fusibility and high crystallization tendency, the developed glass, can be proposed as a promising glass-ceramic binder for the production of high-strength ceramic materials (wear and impact resistant) based on SiC and Si3N4 with reduced sintering temperatures.

Preparation and properties of phosphogypsum-based calcined coal gangue composite cementitious materials

Phosphogypsum (PG) and coal gangue (CG), as the largest solid waste today, the effective utilization of this part of the resource can help to alleviate environmental pollution and resource waste. The aim of this study was to utilize the excellent thermal insulation properties of original PG and the regulation of hydration products by calcined coal gangue (CCG) to produce phosphogypsum-based calcined coal gangue composite cementitious materials (PBCM). The optimal ratio of PBCM was studied through a combination of mechanical properties and thermal insulation properties. Finally, the effect of the foam factor is further investigated. The results show that: CCG can be used as a silicon-rich material with gelling properties to regulate the hydration products generated. The test block with a foam content of 8% has the best performance, with a compressive strength of 2.53MPa and a thermal conductivity of 0.1427W/(m·K). The optimal experimental scheme obtained from the orthogonal test was as follows: The optimal experimental design obtained from orthogonal experiments was as follows: PG, quicklime (QL), sulfoaluminate cement (SAC) and foam contents were 45%, 8%, 8% and 8%, respectively. The CCG: cement and water-solid ratios (W/S) were 3:7 and 0.275, respectively. The development of high-performance composites presented in this study is conducive to enhancing waste utilization and provides a novel approach as well as a theoretical foundation for insulating building materials in practical engineering applications.

Influence of magnetic interaction on four-peak GMI profile in FINEMET/Fe35Ni65 composite ribbons

The study of magnetic interactions is crucial in understanding magnetic materials, where both exchange coupling and dipole interactions significantly affect the magnetic properties of composite materials. Separating and utilizing these two types of interactions have consistently been a research focus. In this study, FINEMET/Fe35Ni65 composite ribbons with varying coating thicknesses were fabricated using magnetron sputtering. Notably, obvious four-peak giant magnetoimpedance profiles can be observed as the Fe35Ni65 film thickness varied from 10 to 50 nm. Additionally, the manifestation of the four-peak profile was attributed to the variation in the magnetic properties in the FINEMET ribbon induced by exchange coupling and dipole interaction. This analysis is crucial for advancing our understanding of the underlying physical mechanisms of magnetic interactions in composite ribbons.

Investigation of Elaeocarpus ganitrus seed (EGs) powder as a sustainable composite biomaterial: Effects of particle size on the mechanical, frictional, and thermal properties for potential biomedical applications

This study explores the potential of Elaeocarpus ganitrus seed (EGs) powder as a sustainable composite biomaterial, focusing on its particle size effects on the mechanical, frictional, and thermal properties of composite materials for potential biomedical applications such as prosthetics and implants. Composite specimens were produced using the compression hot molding method, utilizing EG powder particles of varying sizes (120, 140, and 200-mesh sieving). The influence of EG powder particle size on key properties was systematically investigated. The findings reveal that reducing the particle size of EGs leads to a decrease in density and hardness of the composite, with the largest particle size (BP1) resulting in the highest density and hardness. Friction coefficient measurements indicated suitability for biomedical applications where surface interaction and wear resistance are critical, such as joint prosthetics. Thermal analysis showed that BP1 exhibited superior thermal stability, with a maximum decomposition temperature (Tmax) exceeding 375 °C. Differential scanning calorimetry identified significant differences in glass transition temperature (Tg) and crystallization temperature (Tc) across specimens. The composites demonstrated exceptional thermal performance, surpassing previous benchmarks for biomaterials in high-temperature environments. The mechanical and thermal characteristics of Specimen BP1—2.725 g/cm3 density, 74 Shore D hardness, 0.159 coefficient of friction, 93.3% total residual, 378.14 °C Tmax, 426.25 °C Tc, and 376.87 °C Tg—suggest its potential for biomedical applications requiring durability and thermal resilience, such as in orthopedic devices and tissue engineering scaffolds.

Modifiers for the preparation of starch composites under mechanochemical activation: An extended set of criteria

Modification of starch with synthetic polymers under mechanochemical activation is a convenient way to regulate the operational properties of composite materials. The widespread use of this approach is limited by the lack of data on the influence of synthetic polymer nature on the properties of starch and the absence of clear criteria for modifiers selection in the form of aqueous dispersions. To eliminate existing problems, the work proposes to use five integral criteria − polarity, hydrophilicity, and flexibility of synthetic modifiers, as well as particle size and ζ-potential of their aqueous dispersions. To achieve this goal, we studied the dielectric constant, contact angles, IR spectra, and dynamic mechanical properties of four acrylic copolymers and an aliphatic polyurethane. Using the mechanochemical activation, blends and composite films based on corn starch and synthetic modifiers (80:20) were manufactured. Methods of rotational viscometry, X-ray diffraction analysis, DMA, mechanical tests, and moisture permeability allowed us to reveal the influence of the modifier integral parameters on the rheological characteristics of the molding blends and the impact of joint mechanical activation on them, as well as on the crystal structure of the composites, their storage modulus, strength, and transport characteristics.

Exploring the mechanisms of thermal insulation and heat conduction properties of composite materials based on simulation models

Exploring the mechanisms of thermal insulation and heat conduction properties of composite materials based on simulation models

Research on the Mechanical Properties of Composite Grouting Materials Based on Ordinary Portland–Sulphoaluminate Cement

This study aimed to enhance the mechanical properties of calcium sulfoaluminate cement grouting materials (HCSA) by investigating the effects of ordinary Portland cement (OPC) content, the ratio of quicklime to gypsum, and the dosage of sodium aluminate on the compressive strength of the OPC-CSA composite system. The results indicate that as the OPC content increases, the compressive strength of the blended cement initially increases and then decreases, reaching a maximum at a 60% OPC replacement ratio within the experimental group. The addition of an appropriate amount of OPC to the CSA composite system effectively prevents the regression of compressive strength. With an increase in quicklime content, the compressive strength of the samples at various ages first increases and then decreases, with the optimal ratio of quicklime to gypsum found to be 2:8. Furthermore, sodium aluminate, used as an activator, when increased in dosage, leads to an initial increase followed by a decrease in the compressive strength of OPC-CSA samples, with an optimal incorporation rate of 0.75%, significantly enhancing the strength of the blended cement. In the orthogonal experiments, the dosage of sodium aluminate was identified as the most influential factor affecting the compressive strength of the composite grouting materials.

Study of mechanical properties of composite materials reinforced with aluminum fibers

This study investigates the mechanical properties of composite materials reinforced with aluminum fibers of varying lengths and concentrations. The research aims to evaluate the effects of fiber reinforcement on both flexural and compressive strengths, using fibers of three distinct lengths (2×20 mm, 2×30 mm, and 2×40 mm) and four different concentrations (0.5%, 1%, 1.5%, and 2%) by weight within the composite matrix. Mechanical tests were performed after 28 and 56 days of curing to assess the influence of fiber reinforcement over time. The results demonstrate that increasing fiber length and concentration generally improves the flexural and compressive strengths, with the most notable gains observed at moderate fiber content. However, the study also finds that excessively high fiber percentages may lead to diminishing returns in strength performance, possibly due to fiber agglomeration or stress concentration effects. These findings provide valuable insights into optimizing the design of fiber-reinforced composite materials for various structural applications, enhancing both performance and material efficiency.

Influence of dammar resin on the mechanical properties of composites reinforced with corn husk and paper waste

This study aimed to investigate the influence of dammar resin on the mechanical properties of composite materials reinforced with corn husk and paper waste laminates. Different percentages of dammar resin (50%, 60%, and 70%) were added to the matrix while keeping the reinforcement constant. For all samples, the ratio was maintained at 40% matrix and 60% reinforcement. With the experimental results obtained, statistical analyses were conducted: two-way analysis of variance (ANOVA), Levene’s test, Shapiro-Wilk test, and ANOVA post hoc (with Bonferroni correction). The null hypothesis stated that dammar resin does not influence the mechanical properties. For all tests considered, the null hypothesis was rejected (p < 0.05), the variances were homogeneous (p > 0.05), and the data followed a normal distribution (p > 0.05). It was found that dammar resin had a significant influence on the mechanical properties as the percentage increased from 50% to 70% (p < 0.0083). For each test, based on already known premises, an explanation of the phenomenon that could occur due to the insertion of dammar resin was provided, serving to complement and validate the statistical estimations.

Influence of carbon nanotubes on the absorption performance and mechanical behavior of basalt fiber composite materials

AbstractBasalt fibers (BF) are widely used in shipbuilding due to their excellent corrosion resistance. However, basalt fibers do not possess good electromagnetic wave absorption properties, failing to meet the stealth performance requirements of ships. Therefore, this study focuses on basalt fiber composite materials, modifying the matrix by adding different amounts of carbon nanotubes (CNTs). Carbon nanotube‐basalt fiber‐epoxy resin absorptive composite materials are prepared using Vacuum Assisted Resin Transfer Molding (VARTM) technique to investigate the influence of CNT content on the materials. Samples with added CNTs can effectively absorb electromagnetic waves in the low‐frequency range, reducing surface reflectivity. In the high‐frequency range, the impedance matching value of the samples initially increases slowly. When the CNT content reaches 1.5 wt%, at a thickness of 2.5 mm and a frequency of 9.6 GHz, the minimum reflection loss of the sample is −14.40 dB, with an effective absorption bandwidth of 0.7 GHz. Also, CNTs can enhance the mechanical properties of composite materials. With increasing CNT content, both the bending strength and tensile strength of the composite materials are improved. When the CNT content reaches 1.5 wt%, the average tensile fracture strength of the material increases by 21%, and the bending strength increases by 9%.Highlights Enhanced low‐frequency electromagnetic wave absorption from CNTs and reduced polarization. Improved impedance matching and attenuation at high frequencies with CNTs. Significant enhancement in flexural and tensile strength due to CNTs and basalt fibers.

Eggshell bio-derived hydroxyapatite particle-wool/polyester staple fibers hybrid reinforced epoxy bio-composites for biomedical services

This study assessed the impact of hybrid reinforcement from natural and synthetic materials on the wear and mechanical properties of epoxy-based composite materials needed for biomedical applications. Hydroxyapatite was synthesized from eggshells using the hydrothermal method, while wool fiber was obtained from cow hair. The hybrid reinforced composites were developed by blending hydroxyapatite particles and the fibers by hand layup method in an open mold production process, with specified amounts of 3–15 wt % reinforcement. The characterized properties included tensile and flexural strengths, impact energy, wear resistance, and hardness. A scanning electron microscopy study was conducted to analyze the adhesion between the matrix and reinforcements at the interface, providing valuable insights into the overall integrity of the composites. The results showed a significant increase in the properties of the hybrid reinforced composites when compared with the pristine sample. In particular, the 6 wt% reinforced composite enhanced 61.14 % in tensile strength and 160.79 % enhanced 61.14 % in tensile strength and 160.79 % in flexural strength. Thus, the study shows that substituting synthetic fibers with hybrid organic-based reinforcement offers a viable approach for developing sustainable materials with improved mechanical properties suitable for biomedical applications.

The role of lignin as interfacial compatibilizer in designing lignocellulosic-polyester composite films

Advancing nanocomposites requires a deep understanding and careful design of nanoscale interfaces, as interfacial interactions and adhesion significantly influence the physical and mechanical properties of these materials. This study demonstrates the effectiveness of lignin nanoparticles (LNPs) as interfacial compatibilizer between hydrophilic cellulose nanofibrils (CNF) and a hydrophobic polyester, polycaprolactone (PCL). In this context, we conducted a detailed analysis of surface-to-bulk interactions in both wet and dry conditions using advanced techniques such as quartz crystal microbalance with dissipation (QCM-D), atomic force microscopy (AFM), water contact angle (WCA) measurements, broadband dielectric spectroscopy (BDS), and inverse gas chromatography (IGC).QCM-D was employed to quantify the adsorption behavior of LNPs on CNF and PCL surfaces, demonstrating LNPs’ capability to interact with both hydrophilic and hydrophobic phases, thereby enhancing composite material properties. LNPs showed extensive adsorption on a CNF model film (1186 ± 178 ng.cm−2) and a lower but still significant adsorption on a PCL model film (270 ± 64 ng.cm−2). In contrast, CNF adsorption on a PCL model film was the lowest, with a sensed mass of only 136 ± 35 ng.cm−2. These findings were further supported by comparing the morphology and wettability of the films before and after adsorption, using AFM and WCA analyses. Then, to gain insights into the molecular-level interactions and molecular mobility within the composite in dry state, BDS was employed. The BDS results showed that LNPs improved the dispersion of PCL within the CNF network. To further investigate the impact of LNPs on the composites’ interfacial properties, IGC was employed. This analysis showed that the composite films containing LNPs exhibited lower surface energy compared to those composed of only CNF and PCL. The presence of LNPs likely reduced the availability of surface hydroxyl groups, thus modifying the physicochemical properties of the interface. These changes were particularly evident in the heterogeneity of the surface energy profile, indicating that LNPs significantly altered the interfacial characteristics of the composite materials.Overall, these findings emphasize the necessity to control the interfaces between components for next-generation nanocomposite materials across diverse applications.

An investigation mechanical properties of areca fiber composite material

An investigation mechanical properties of areca fiber composite material

Graphitic carbon nitride/titania nanotube arrays for photoelectrochemical oxidation of methanol under visible light

In this study, the fabrication of ordered and vertically oriented titanium dioxide nanotubes (TiO2 NT) array sensitized with graphitic carbon nitride (g-C3N4) nanosheets (g-C3N4 NS/TiO2 NT) was demonstrated as an attractive class of photocatalysts for the visible-light-driven photoelectrochemical oxidation of methanol. The phase and composition of the fabricated g-C3N4 NS/TiO2 NT structures and their precursors were investigated using X-ray powder diffraction (XRD). The morphological and topological characteristics of the prepared materials were studied using scanning electron microscopy (SEM). Raman spectroscopy was employed to study the electronic properties of composite material. Upon the fabrication, characterization, and use of the prepared structures for photoelectrochemical oxidation of methanol under visible-light illumination (50 W halogen lamp, 0.1 M KOH), the g-C3N4 NS/TiO2 NT array showed a significant increase in the photocurrent (96.2 μA cm−2) compared to the TiO2 NT electrode (79 μA cm−2) with 1.2 times enhancement factor. Moreover, decorating the TiO2 NT array resulted in enhanced dark light density that is 8.7 times more than that of the TiO2 NT electrode. The improved photo- and electrochemical properties of the prepared g-C3N4 NS/TiO2 NT could arise from the synergistic effects of g-C3N4 NS decoration and the unique structural properties of the fabricated vertically aligned TiO2 nanotube arrays. The TiO2 NT/g-C3N4 NS composite modified photo-electrode offers 22.55 times the ambient condition “light off” of the TiO2 NT electrode and 2.3 times the irradiated ones. The present study suggests a simple, stable, reusable, and cost-effective approach for the preparation of g-C3N4 NS/TiO2 NT photocatalyst for designing a DMFC.