Mechanical Properties Of Polymer Composites Research Articles

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.

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.

Plant Fiber Reinforced Polymeric Composites for Engineering Applications: A Review

Purpose: Scientists are looking for unconventional materials to achieve sustainable goals and reduce the consumption of non-renewable resources. This review focuses on polymeric composite materials with improved properties and low cost, synthesized from plant fibres and their potential fields of application. Theoretical Framework: Natural fibers, which are globally accessible, play a crucial role in improving thermal and mechanical properties when incorporated into polymers. With remarkable stiffness-density, strength and lightness, fibers stand out as promising, low-cost composite materials for applications in various areas of engineering. The plant diversity of the Amazon makes Brazil one of the largest global producers of natural fibers, providing an opportunity to develop new sustainable technologies. Method/Design/approach: Systematic literature review addressing potential applications of polymeric materials with plant fibers, fiber extraction methods, influence of fiber surface treatments and composite processing, and mechanical properties of polymeric composites with fibers. Results: Polymer composites reinforced with natural fibers are emerging as sustainable alternatives to synthetic materials, driven by their ecological nature, easy availability, low cost and biodegradability. A systematic review of the literature revealed that the mechanical properties of these composites are intrinsically linked to various factors, such as fibre orientation and length, which require careful optimization. In addition, it was observed that surface treatments, such as chemical acetylation and alkaline treatments, play a crucial role in improving the properties of plant fiber reinforced materials. These processes are responsible for removing impurities present in the cell walls of the fibers, such as lignins, waxes and hemicellulose, among others. Given Brazil's significant potential in the production of natural fibers, their application in industrial contexts is promising, offering an environmentally friendly solution for waste management. Thus, it is believed that, in the future, plant fibers will gain even more prominence, possibly effectively replacing the synthetic fibers widely used in the market. Research implications: This work contributes to the development of innovative, low-cost, sustainable materials, capable of minimizing the consumption of non-renewable resources and with potential applicability. Originality/value: The results are promising for the development of environmentally sustainable polymer composites with plant fibers, with wide applications in engineering.

Preparing strong, tough, and high-barrier biobased polyester composites by regulating interfaces of carbon nanotubes

Carbon nanotubes (CNTs) have been regarded as ideal functional fillers for enhancing superior mechanical properties of polymer composites. However, the performances of CNTs-based composites are well below the theoretical values, due to the poor dispersion of inert CNTs and weak interfacial interaction with the polymer matrix. Herein, “hydrothermal and in-situ growth” approach is induced to synthesize multiscale TiO2@CNTs functional fillers. Such the TiO2@CNTs show excellent dispersibility and strong interfacial bonding with matrix. The biobased TiO2@CNTs/poly (ethylene furandicarboxylate) (TCP) composite films are prepared via loading a small amount (0.05–0.2 wt%) of TiO2@CNTs. When the mass content of fillers is 0.2 wt%, TCP composite film exhibits the optimal of strength (80 MPa), Young's modulus (4.12 GPa), and toughness (1.2 MJ/m3). Moreover, the presence of TiO2 nanoparticles endow the films with excellent oxygen barrier and UV-shielding properties. We believe these composite films promise a spread application potential in high-performance food packing materials.

Bidispersity Improves the Toughness and Impact Resistance of Star-Polymer Thin Films.

Branched polymer architectures are used to tune the mechanical properties of impact-resistant thin films through parameters, such as chain length and grafting density. While chain dispersity affects molecular properties, such as interpenetration and entanglements, structure-property relationships accounting for dispersity are challenging to obtain experimentally and are often neglected in computational models. We employ molecular dynamics simulations to model the high-rate tensile elongation and nanoballistic impact of thin films composed of bidisperse star polymers with varying arm lengths. We find that, at fixed molecular weight, high dispersity can significantly enhance the toughness and impact resistance of the films without decreasing their elastic modulus. Bidisperse stars with fewer longer arms are less entangled, but stretch and interpenetrate for longer times during crazing, leading to increased toughness. These findings highlight controlled dispersity as a design strategy to improve the mechanical properties of polymer composites across Pareto fronts.

Study of the influence of accelerated aging on the physical and mechanical properties of polymer composites containing rubber, polyethylene and poly(ethylene terephthalate) waste

Polymer composites have been used in civil engineering for years, but the need to follow current trends, and thus the need to modify these materials, requires systematic monitoring of their durability. The article describes the results of research on concrete-like resin composites, the main ingredients of which are: synthetic resin, hardener and aggregate. This material (control mortar (c)) was modified in two ways: within the epoxy resin matrix and/or sand aggregate, with such recycled materials as: poly(ethylene terephthalate) (PET) from bottles (resin substitute in the amount of 9% by mass), polyethylene (PE) from plastic bags or rubber from car tires (R) - aggregate substitutes in the amount of 10% by volume. Experimental tests of mortar samples subjected to accelerated aging processes in a chamber simulating irradiation and rain cycles allowed the analysis of the physico-mechanical properties of composites depending on the degree of exposure to solar radiation and moisture. The results of the accelerated aging studies were used to compare the relative behavior of composites with different compositions. For this purpose, analyses based on scanning electron microscopy were also performed. Both the type of waste and the aging time significantly differentiate the strength parameters of mortars. MPa. All samples clearly changed color, but even after 2000 h of accelerated aging, the flexural strength exceeds 30 MPa and the compressive strength exceeds 110 MPa, while the control samples matured in laboratory conditions had a flexural strength of 18 MPa and a compressive strength of 74.3 MPa. The cost-economic analysis confirmed that incorporating waste into composites is beneficial, even if they are exposed to aging factors.

Improving mechanical properties of huntite hydromagnesite reinforced flame retardant polymer composites with calcite and zeolite minerals

AbstractAlthough inorganic minerals used as flame retardants in firefighting are much safer alternative to halogen‐containing ones, it is seen that while they impart non‐flammability, they impair some mechanical properties of polymer composites. In this study, calcite and zeolite minerals, with well‐known incombustibility properties, were used together with huntite hydromagnesite as auxiliary minerals to obtain better mechanical properties. In this context, a synergistic effect was created by adding zeolite and calcite to polymer composite systems containing huntite hydromagnesite, and flame retardant polypropylene matrix composites were produced using a twin screw extruder. The thermal properties of the produced composites were determined by thermogravimetric analysis (TGA). Tensile test was applied to the samples to determine their mechanical properties. Structural and morphological properties were characterized by scanning electron microscopy (SEM) analysis. It was found that with an additive load of 60% by weight, the modulus of elasticity of pure polypropylene was increased from 1215 to 3362 MPa. In addition, by loading zeolite together with huntite hydromagnesite, the maximum tensile strength increased from 15.6 MPa to 22.9 MPa, resulting in an increase of 46.80%. Consequently, the synergistic effect obtained by using zeolite with huntite hydromagnesite improved the mechanical properties of the composite.

Enhancing thermal mechanical properties of polymer composites with hollow porous fillers

Incorporating inorganic fillers is a common strategy for reducing the coefficient of thermal expansion (CTE) in polymers, but it is often associated with limited efficiency and a sacrifice in mechanical compliance. Current approaches mainly involve surface modification of fillers to overcome these challenges, but a significant proportion of fillers remain underutilized. In this study, we introduced hollow porous SiO2 particles as fillers, utilizing both their external and internal surfaces to interact with the matrix. Moreover, the hollow porous structure allows the matrix to penetrate into the filler cavities, creating a unique mechanical interlock with the matrix. These combined effects result in a higher efficiency for CTE reduction and a significant improvement in the glass transition temperature. Furthermore, the hollow structure reduces the modulus of the fillers, resulting in a lower composite modulus compared to solid SiO2 counterparts. This approach offers a new avenue for enhancing the thermal mechanical properties of polymer composites.

Effect of particle size distribution on the cryogenic mechanical properties of triple‐base propellants

AbstractFillers play a decisive role in the mechanical properties of polymer composites. In this paper, different particle sizes of nitroguanidine were obtained to regulate the internal filler structure of triple‐base propellants (TBP) to improve their mechanical response in different environments. A series of morphological and structural characterizations on nitroguanidine (NQ) particles were conducted using techniques. The results indicated that the obtained NQ particles maintained a high level of crystalline quality while preserving their molecular integrity. The mechanical properties of TBP were systematically evaluated under various loading conditions, including cryogenic tensile, compressive, and impact loads, as well as dynamic thermomechanical effects. Additionally, three‐point bending simulations were employed to elucidate the mechanical responses and damage mechanisms. Under axial tensile and compressive loads, reducing the particle size of NQ significantly enhanced the tensile and compressive strength. The maximum tensile strength and compressive strength can reach 344.62 MPa and 104.79 MPa. Moreover, the compressive failure mode transitioned from cracking to axial shrinkage. Conversely, when subjected to radial bending loads, TBP exhibited contrasting behavior, including a decrease in the glass transition temperature from 84.73°C to 76.93°C and a non‐monotonic trend in impact strength (initially increasing from 4.96 to 8.85 kJ/m2 and then decreasing to 2.27 kJ/m2). This study provides valuable insights into the mechanical performance of TBP, supporting the development of high‐energy, high‐strength TBP formulations.Highlights SEM analysis confirms the pronounced orientation effect of rod‐like NQ. The orientation and particle size of NQ decide TBP's radial impact resistance. Submicron NQ enhances the compression resistance property of TBP. Submicron NQ brings about a shift in the microscopic damage morphology of TBP.

Exploring Anisotropic Mechanical Characteristics in 3D-Printed Polymer Biocomposites Filled with Waste Vegetal Fibers

The fiber-filled polymer composite is one of the best materials which provides a symmetrical superior strength and stiffness to structures. With the strengthening of people’s environmental protection and resource reuse consciousness, the development of renewable materials, especially natural fiber-filled polymer composites, is receiving great attention. This study investigated the mechanical properties of polymer composites incorporating waste materials from the food processing industry and agricultural sources. Waste vegetal fiber-filled polymer biocomposites (WVFFPBs) with varying fiber types and 3D printing orientations were systematically fabricated. Subsequently, the tensile tests were executed to comprehensively assess the anisotropic mechanical behaviors of the WVFFPBs. The results demonstrated that WVFFPBs performed excellent anisotropic mechanical properties compared to pristine matrix samples as print orientation changed. As the printing angle increased from 0° to 90°, the tensile mechanical properties of the WVFFPBs displayed a decreasing trend. Moreover, the print orientation–anisotropic mechanical behavior relationship of 3D-printed WVFFPBs was revealed through the analysis of the material manufacturing characteristics and damage features.

The Influence of Pressure in the Infusion Method Upon Mechanical Properties of Polymer Composites

The Influence of Pressure in the Infusion Method Upon Mechanical Properties of Polymer Composites

Substantial improvement of thermal conductivity and mechanical properties of polymer composites by incorporation of boron nitride nanosheets and modulation of thermal curing reaction

AbstractThermal conductive polymer‐based composites synchronously with stable dielectric and excellent mechanical properties are urgently needed for high‐temperature‐resistant electronic devices. Here, a significant improvement in the thermal conductivity (TC), thermal stability, dielectric, and mechanical performance was simultaneously achieved in the polyarylene ether nitrile (PEN)/divinyl siloxane‐bisbenzocyclobutene (BCB) matrix through the incorporation of boron nitride nanosheets (BNNS) combined together with the post‐solid phase chemical reaction technique. The significant increase in the effective filler‐filler and filler‐crystal contacts in the composites was the main reason for the improvement in TC and dielectric constant. Besides, glass transition temperature (Tg) and mechanicals were enhanced in the presence of cross‐linked networks. By synchronously adding 15 vol% BNNS, the TC of composites after treatment reached up to 5.582 W/m.K, enhanced by 4.4 times higher than untreated. The dielectric constant was down to 2.93 at 1 MHz and the loss remained at a relatively low level. Meanwhile, the composite showed significantly enhanced thermal stability, mechanicals, and hydrophobicity (Tg = 336°C, T5% = 529°C, tensile strength and modulus was 94.5 MPa and 5.3 GPa, respectively, the contact angle was 101.76°). Thus, it promotes an effective strategy for fabricating a high‐performance‐polymer composite, which has the potential used in electronic materials.Highlights Crystallization‐crosslinking strategy optimizes overall performance. Crystals fill gaps between BNNS layers and connect thermal conductive pathway. Crosslinked networks limit molecular chain motion to reduce phonon scattering. The highest TC of the PEN/BCB/BNNS composite is up to 7.451 W/m.K. Thermal property shows significant improvement after crosslinking especially Tg.

Manufacturing and characterization of sustainable and recyclable wood-polypropylene biocomposites: Multiprocessing-properties-structure relationships

In this study, sustainable polymeric materials with a polypropylene matrix reinforced with wood waste were developed for structural applications. The new polymer biocomposites (WPCs) were evaluated for their mechanical and structural properties regarding their susceptibility to multiple processing. As thermo-mechanical degradation processes are associated with the repeated processing of plastics, which causes changes in the properties and structure of these materials. Therefore, to determine the extent to which the composites can be used under operating conditions, the composites were examined by DMA. As a result of the study observed some effects caused by the repeated effects of shear stress and temperature on the rheological and mechanical properties of polymer composites. The first of these is related to a decrease in viscosity of WPC composites subjected to the six times processing and changes in flow conditions during extrusion and injection moulding due to the degradation of the polypropylene matrix. As the viscosity of the composites decreased, a reduction in tensile strength and other mechanical properties of the polypropylene matrix was noted. On the other hand, the second effect observed leads to the conclusion that, as the composites' processing cycles increase, the WPC composite's mechanical properties increase due to an increase in the degree of homogenization of the individual components of the WPC composition. This study aims to describe the relationship between these two primary processes and to determine the relationship between the properties and the structure of the new WPCs.

A multiscale model for predicting mechanical properties of polymer composites

Owing to the multiscale structural characteristics and complex internal coupling, the evaluation of mechanical properties of a polymer composite upon its microstructural information is challenging. Herein, we propose a multiscale method for predicting the mechanical properties of polymer composites by accounting for the contributions of the polymer matrix and those from particle filling and particle–matrix interactions. The former contributions are addressed with the reference polymer matrix by means of molecular dynamic simulation, while the latter are described by a revised continuum model with the input from basic experimental data. The proposed model, validated with the corresponding experimental measurements, indicates that a small difference in the matrix composition can lead to a significant deviation of 60% in the ultimate stress at room temperature, and that the particle size distribution has a synergistic effect, resulting in a nonmonotonic dependence of the mechanical properties on the average particle size. This study provides a feasible engineering tool for evaluating the mechanical properties of polymer composites.

Ceramic-inorganic polymer composites for protection against electromagnetic radiation mechanical properties designing

The possibility of designing mechanical properties of ceramic-inorganic polymer composites for protection against electromagnetic radiation is considered. As a result, the mechanical properties of polymer composite based on polyamide, modified with ceramic-inorganic graphite-ferromagnetic fillers (silicon carbide, chromium oxide Cr2O3 and graphite) was received and optimized. The strength characteristics complex of ceramic-inorganic polymer composites with silicon carbide SiC, chromium oxide Cr2O3 and graphite content in diapason 5-15 % wt. were studied. It was established that the optimal strength characteristics can be received using binary modification of polyamide with ceramic-inorganic graphite-ferromagnetic fillers: polyamide 6 – SiC 10% wt. – Cr2O3 10% wt. and polyamide 6 – SiC 10% wt. – graphite 10% wt. Using mathematical modeling, it was established that the polyamide 6 – SiC 10% wt system is the most optimal for three-component complex modification with ceramic-inorganic graphite-ferromagnetic fillers – Cr2O3 10% wt. – graphite 10% wt. By design experimental-statistical mathematical models in equal regressions, mathematical optimization of mechanical properties of polymeric ceramic-inorganic composites contains for protection against electromagnetic radiation was carried out. Designed polymer ceramic-inorganic composites for protection against electromagnetic radiation according to their strength characteristics can be used for modern radio absorbing materials production.

Enhancement of thermal and mechanical properties of polymer composite using a novel milled bamboo filler

AbstractThis work presents the thermal and mechanical characterization of epoxy composites reinforced with different fillers developed by modifying thermo‐mechanically extracted bamboo micron fibers. The modification of bamboo fibers was done by adding carbon nanoparticles to their surface and also by making powdered fillers using the process of ball milling. A decrease in water absorption in case of surface coated bamboo fibers was observed. The glass transition behavior was enhanced for composites filled with milled bamboo fillers as compared to neat epoxy. Better mechanical properties were observed for composites reinforced with milled bamboo fillers compared to that of composites filled with bamboo fibers. The highest tensile strength (90.258 MPa) was observed for composites reinforced with 5 wt% of milled bamboo fillers depicting an increase of 93.01% compared to that of neat epoxy (46.762 MPa).Highlights Bamboo fibers were modified with a sizing agent and carbon nanoparticles. A novel “milled bamboo filler” was produced and incorporated in composites. Thermal properties of epoxy composite were enhanced by the novel filler. Tensile strength of the composite was significantly enhanced. The novel filler has the future scope of application in various composite products.

Effect of intercalated and exfoliated graphite particles on the mechanical properties of polymer composite: A micromechanics-computational approach

This study investigated the effects of intercalation and exfoliation of the graphite flake particles on the mechanical properties of elastomeric composites using analytical, computational, and experimental techniques. Relying on the modified Eshelby and incremental Mori–Tanaka approach, a new micromechanics model was proposed to estimate Young’s modulus and develop a constitutive model for expanded graphite (EG)-filled elastomer in finite strain deformation. It was found that when the initial graphite flakes expanded, the actual volume fraction and ultimate aspect ratio of the dispersed particles significantly affected the mechanical properties of the EG-reinforced composites. The present model and subsequent predictions reflect the initial flake diameter, actual volume fraction, ultimate aspect ratio of the particles, and other convenient physical properties of the composite constituents. In addition, molecular dynamics simulations were performed to evaluate the elastic properties of the EG-Matrix interphase region using the COMPASS force field function. The MD results showed that Young’s modulus of the interphase region increased significantly as the quantity of the graphene layer increased. The micromechanics-constitutive model results were validated using the experimentally determined stress–strain relation of the composites. EG- and CB-elastomer nanocomposite specimens were fabricated and tested in the experimental program. Field emission scanning electron microscopy (FESEM) analysis of the cryo-fractured surfaces of the elastomer compounds showed good interactions between the constituents. Numerical computations indicated that the proposed model incorporating the new parameters could accurately predict the experiment at a small particle concentration.

An accelerated strategy to characterize mechanical properties of polymer composites using the ensemble learning approach

Screening new materials and decoding their structure-property relationships is a time-consuming and costly task in the laboratory. This research proposes the use of machine learning (ML) algorithms with a new train-test splitting strategy to predict the complete stress-strain curves of polymer composites based on their compositional, environmental, and processing conditions using data extracted from an open-source database. Both the artificial neural network (ANN) and ensemble learning (EL) models demonstrated acceptable fit to the training datasets, yielding root mean squared errors (RMSEs) below 3.2 MPa. However, EL models demonstrated superior performance by reducing the RMSE of the testing data by an average of 61% for polyethylene terephthalate (PET) composites and 30% for polycarbonate (PC) composites, compared to the wide ANN models. Additionally, the developed EL models reduced the training time from a few hours (∼4 h on average) for wide ANNs to just a few seconds. The results of this study imply that relying solely on ANN models may not always provide the best solution for a given problem in materials science, and that EL models should be considered as a viable alternative, particularly in cases where data are limited. This study will pave the way for the automated design and characterization of advanced composites, while reducing the costly and laborious experiments in keeping with the vision of smart manufacturing and Industry 4.0.

Nanoscale Mechanical Properties of Polymer Composites and Their Impact on Bulk Material Performance.

Nanoscale Mechanical Properties of Polymer Composites and Their Impact on Bulk Material Performance.

Some problem questions in studying the properties of dynamically vulcanized polymer systems based on ethylene/1-hexene copolymer and nitrile butadiene rubber

The article presents the results of a study of the influence of the type and concentration of nitrile butadiene rubber on the main physical and mechanical properties of polymer compositions based on compatibilized ethylene/1-hexene copolymer (EHC*). SKN-18, SKN-26, and SKN-40 were used as nitrile butadiene rubber. The compatibilizer – polyethylene-graft-methacrylic acid was used to improve the compatibility of the mixed components of the mixture. At the first stage, the task of the study was to investigate the effect of the concentration of the considered nitrile rubbers on such properties of the compositions as yield strength, tensile strength, elongation at break, flexural strength, melt flow rate and heat resistance. It was found that, regardless of the type of used nitrile butadiene rubber, with an increase in its content in the composition of the ethylene/1-hexene copolymer, a regular decrease in strength parameters, heat resistance, and melt fluidity is observed. It is shown that with the loading of 30 wt% SKN-18 or 40 wt% SKN-26 and SKN-40 into the composition of the ethylene/1-hexene copolymer phase inversion occurs in the composite materials, according to which the dispersed phase becomes a dispersed medium. The thermomechanical properties of the considered samples were studied. It was found that in those samples in which phase inversion occurred, a region of a highly elastic plateau is formed, which increases with an increase in the content of the rubber component. This area indicates the formation of elastomer with rubber properties. The regularities of crystallization of the compositions depending on the content of the amorphous component were studied by the method of stepwise dilatometry. The mechanism of crystal formation was studied depending on the content of the amorphous component. The influence of the crosslinking agent concentration – dicumyl peroxide on the main properties of dynamically vulcanized elastomers has been studied.