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J. Compos. Sci., Volume 7, Issue 4 (April 2023) – 43 articles

Cover Story (view full-size image): Self-healing polymers and nanocomposites form an important class of materials having the ability to reversibly heal their damages. In the aerospace sector, thermosets/thermoplastic polymers filled with carbon nanoparticles have gained importance for self-healing of structural damage. Self-healing performance depends on the addition of nanocapsules or carbon nanoparticles, microphase separation, matrix–nanofiller interactions, and polymer–nanofiller inter-diffusion. Self-healing nanocomposites have found potential in aerospace structural components, panels, laminates, membranes, and coatings. Future high-performance self-healing nanocomposites may further broaden the scope of self-healing materials for aerospace structures. View this paper
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13 pages, 7879 KiB  
Article
Plasma Synthesis and Characterization of PANI + WO3 Nanocomposites and their Supercapacitor Applications
by Nikolay Sirotkin and Anna Khlyustova
J. Compos. Sci. 2023, 7(4), 174; https://doi.org/10.3390/jcs7040174 - 20 Apr 2023
Cited by 2 | Viewed by 1789
Abstract
In this work, an underwater impulse discharge initiated in polyaniline (PANI) aqueous dispersion between tungsten rods is applied to produce metal oxide nanoparticles and create polymer nanocomposites. The prepared materials were analyzed by X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy [...] Read more.
In this work, an underwater impulse discharge initiated in polyaniline (PANI) aqueous dispersion between tungsten rods is applied to produce metal oxide nanoparticles and create polymer nanocomposites. The prepared materials were analyzed by X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). XRD, FTIR, and TEM confirmed the presence of tungsten oxide particles in the final composite, while spectroscopic characterization revealed the interaction between the metal oxide and PANI. The results showed that the incorporation of WO3 into the PANI matrix could improve the optical bandgap of the nanocomposites. In addition, the electrochemical performance of the hybrid nanocomposites was tested by cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD). The results obtained indicated that the PANI + WO3 nanocomposite could be a promising candidate as an electrode material for high-power supercapacitor applications. Full article
(This article belongs to the Section Polymer Composites)
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16 pages, 4638 KiB  
Article
Comparative Thermoelectric Properties of Polypropylene Composites Melt-Processed Using Pyrograf® III Carbon Nanofibers
by Antonio J. Paleo, Beate Krause, Ana R. Mendes, Carlos J. Tavares, Maria F. Cerqueira, Enrique Muñoz and Petra Pötschke
J. Compos. Sci. 2023, 7(4), 173; https://doi.org/10.3390/jcs7040173 - 20 Apr 2023
Cited by 4 | Viewed by 1340
Abstract
The electrical conductivity (σ) and Seebeck coefficient (S) at temperatures from 40 °C to 100 °C of melt-processed polypropylene (PP) composites filled with 5 wt.% of industrial-grade carbon nanofibers (CNFs) is investigated. Transmission Electron Microscopy (TEM) of the two Pyrograf® III CNFs [...] Read more.
The electrical conductivity (σ) and Seebeck coefficient (S) at temperatures from 40 °C to 100 °C of melt-processed polypropylene (PP) composites filled with 5 wt.% of industrial-grade carbon nanofibers (CNFs) is investigated. Transmission Electron Microscopy (TEM) of the two Pyrograf® III CNFs (PR 19 LHT XT and PR 24 LHT XT), used in the fabrication of the PP/CNF composites (PP/CNF 19 and PP/CNF 24), reveals that CNFs PR 24 LHT XT show smaller diameters than CNFs PR 19 LHT XT. In addition, this grade (PR 24 LHT XT) presents higher levels of graphitization as deduced by Raman spectroscopy. Despite these structural differences, both Pyrograf® III grades present similar σ (T) and S (T) dependencies, whereby the S shows negative values (n-type character). However, the σ (T) and S (T) of their derivative PP/CNF19 and PP/CNF24 composites are not analogous. In particular, the PP/CNF24 composite shows higher σ at the same content of CNFs. Thus, with an additionally slightly more negative S value, the PP/CNF24 composites present a higher power factor (PF) and figure of merit (zT) than PP/CNF19 composites at 40 °C. Moreover, while the σ (T) and S (T) of CNFs PR 19 LHT XT clearly drive the σ (T) and S (T) of its corresponding PP/CNF19 composite, the S (T) of CNFs PR 24 LHT XT does not drive the S (T) observed in their corresponding PP/CNF24 composite. Thus, it is inferred in PP/CNF24 composites an unexpected electron donation (n-type doping) from the PP to the CNFs PR 24 LHT XT, which could be activated when PP/CNF24 composites are subjected to that increase in temperature from 40 °C to 100 °C. All these findings are supported by theoretical modeling of σ (T) and S (T) with the ultimate aim of understanding the role of this particular type of commercial CNFs on the thermoelectrical properties of their PP/CNF composites. Full article
(This article belongs to the Special Issue Carbon-Based Polymer Nanocomposites)
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15 pages, 5140 KiB  
Article
Hardness Measurements and Interface Behavior of SiC-B4C-Si Multiple Phase Particulate Composites Made with Melt Infiltration and Additive Manufacturing
by Corson L. Cramer, Ercan Cakmak and Kinga A. Unocic
J. Compos. Sci. 2023, 7(4), 172; https://doi.org/10.3390/jcs7040172 - 20 Apr 2023
Cited by 1 | Viewed by 1515
Abstract
Reaction-bonded SiC-B4C-Si ceramic composites were binder jet 3D-printed and subsequently pressureless-melt-infiltrated with molten Si. The addition of B4C aided the Si infiltration to produce a highly dense composite. The microstructures and phases of these composites were examined. The measured [...] Read more.
Reaction-bonded SiC-B4C-Si ceramic composites were binder jet 3D-printed and subsequently pressureless-melt-infiltrated with molten Si. The addition of B4C aided the Si infiltration to produce a highly dense composite. The microstructures and phases of these composites were examined. The measured hardness values of each constituent with Vickers and nanoindentation matched the bulk values, and the macro-hardness values with Knoop and spherical indentation represented the bulk, composite hardness values of all three phases together, which was close to a rule of mixtures value. For particulate-based composites, this is a significant finding. The interfacial bonds of SiC and Si were imaged using scanning transmission electron microscopy to view intimacy, whereas the crack propagation was examined with carefully placed indents. This work demonstrated that pressureless melt infiltration with a reactive particle provides a method to shape non-wetting reaction-bonded ceramic composites with limited shrinkage and high density and provides insights into the mechanical behavior with numerous indentation techniques. Full article
(This article belongs to the Topic Progress in Si-Based Ceramic and Composites)
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14 pages, 10725 KiB  
Article
Additive Manufacturing of Carbon Fiber Reinforced Epoxy Thermoset with Improved Thermomechanical Properties
by Md Sahid Hassan, Antonio Delgadillo, Md Shahjahan Mahmud, Joseph Munoz, Saqlain Zaman, Sofia Gabriela Gomez, Cory Marquez, Johnny C. Ho and Yirong Lin
J. Compos. Sci. 2023, 7(4), 171; https://doi.org/10.3390/jcs7040171 - 20 Apr 2023
Cited by 1 | Viewed by 1328
Abstract
Laser Powder Bed Fusion (LPBF) is a widely used additive manufacturing technique for powder-based polymers and metallic materials. Thermoplastics like Polyamide 12 and Polyamide 6 are commonly used in LPBF; thermosetting polymers are gaining attention due to their superior stability. Epoxies are a [...] Read more.
Laser Powder Bed Fusion (LPBF) is a widely used additive manufacturing technique for powder-based polymers and metallic materials. Thermoplastics like Polyamide 12 and Polyamide 6 are commonly used in LPBF; thermosetting polymers are gaining attention due to their superior stability. Epoxies are a popular thermoset, but some exhibit low physical properties and brittleness, leading to reduced toughness. The work presented in this paper explores the effect of using short carbon fibers (CF) as additives to epoxy-based thermosetting material on physical and thermomechanical properties. A total of six epoxy thermoset/CF composite powder blends were prepared by varying reinforcing materials weight percentages (0 wt%, 0.3 wt%, 0.6 wt%, 1 wt%, 5 wt%, and 10 wt%). Tensile, four-point bending, and dynamic mechanical analysis (DMA) test samples were printed using the LPBF technique. Significant improvements in the physical and thermomechanical properties were obtained in the thermoset composites with 5 wt% of CF due to good adhesion between reinforcing materials and the matrix and a low level of porosity. Fracture surface analysis was performed via scanning electron microscopy (SEM), which provided insight into the influence of CF on the properties of thermosetting composites. The findings of this research demonstrate the feasibility of improving the inferior physical and thermomechanical properties of 3D-printed CF-reinforced epoxy. With a certain amount of CF reinforcement, Young’s modulus and fracture modulus can be increased by around 52% and 259%, respectively. Full article
(This article belongs to the Special Issue Additive Manufacturing of Composites and Nanocomposites)
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21 pages, 20523 KiB  
Article
Mineralogical Characterization of Lithomargic Clay Deposits along the Coastal Belt of Udupi Region of South India
by Deepak Nayak, Purushotham G. Sarvade, Udaya Shankara H. N. and Jagadeesha B. Pai
J. Compos. Sci. 2023, 7(4), 170; https://doi.org/10.3390/jcs7040170 - 19 Apr 2023
Cited by 1 | Viewed by 1598
Abstract
Lithomargic clay is generally found below the lateritic soil along the coastal belt of Karnataka. It is rich in silt content and dispersive in nature. This type of soil is liable to erosion and landslides. The lithomargic clay is largely found in the [...] Read more.
Lithomargic clay is generally found below the lateritic soil along the coastal belt of Karnataka. It is rich in silt content and dispersive in nature. This type of soil is liable to erosion and landslides. The lithomargic clay is largely found in the western coast of South India. At present, coastal belt of Udupi district is witnessing a lot of developments in terms of industry, infrastructures, and other activities. Lithomargic clay is a type of problematic soil, which needs a thorough study to make it suitable to sustain any engineering structure such as buildings, pavements, railways, dams. A characterization and mineralogical study is conducted to identify the presence of minerals and compounds for the various soil samples collected along the coastal belt of Udupi regions using X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), and scanning electron microscopy (SEM) analysis. The primary minerals observed in majority of the regions are quartz, feldspar such as orthoclase, muscovite, and the secondary minerals formed by the decomposition and chemical alteration of primary minerals include sheet minerals such as kaolinite, halloysite, dickite, gibbsite, and illite in high proportions. The study also shows the presence of iron compounds such as fayalite, goethite, and siderite. The majority of the elements observed are oxygen, silicates, aluminum, potassium, and iron which confirms the presence of the compounds identified through XRD analysis. Full article
(This article belongs to the Section Composites Modelling and Characterization)
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22 pages, 10802 KiB  
Article
A Comparative Study on Crack Detection in Concrete Walls Using Transfer Learning Techniques
by Remya Elizabeth Philip, A. Diana Andrushia, Anand Nammalvar, Beulah Gnana Ananthi Gurupatham and Krishanu Roy
J. Compos. Sci. 2023, 7(4), 169; https://doi.org/10.3390/jcs7040169 - 18 Apr 2023
Cited by 9 | Viewed by 2338
Abstract
Structural cracks have serious repercussions on the safety, adaptability, and longevity of structures. Therefore, assessing cracks is an important parameter when evaluating the quality of concrete construction. As numerous cutting-edge automated inspection systems that exploit cracks have been developed, the necessity for individual/personal [...] Read more.
Structural cracks have serious repercussions on the safety, adaptability, and longevity of structures. Therefore, assessing cracks is an important parameter when evaluating the quality of concrete construction. As numerous cutting-edge automated inspection systems that exploit cracks have been developed, the necessity for individual/personal onsite inspection has reduced exponentially. However, these methods need to be improved in terms of cost efficiency and accuracy. The deep-learning-based assessment approaches for structural systems have seen a significant development noticed by the structural health monitoring (SHM) community. Convolutional neural networks (CNNs) are vital in these deep learning methods. Technologies such as convolutional neural networks hold promise for precise and accurate condition evaluation. Moreover, transfer learning enables users to use CNNs without needing a comprehensive grasp of algorithms or the capability to modify pre-trained networks for particular purposes. Within the context of this study, a thorough analysis of well-known pre-trained networks for classifying the cracks in buildings made of concrete is conducted. The classification performance of convolutional neural network designs such as VGG16, VGG19, ResNet 50, MobileNet, and Xception is compared to one another with the concrete crack image dataset. It is identified that the ResNet50-based classifier provided accuracy scores of 99.91% for training and 99.88% for testing. Xception architecture delivered the least performance, with training and test accuracy of 99.64% and 98.82%, respectively. Full article
(This article belongs to the Special Issue Sustainable Composite Construction Materials)
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43 pages, 6419 KiB  
Review
Nanocellulose-Based Thermoplastic Polyurethane Biocomposites with Shape Memory Effect
by Marina Gorbunova, Leonid Grunin, Robert H. Morris and Arina Imamutdinova
J. Compos. Sci. 2023, 7(4), 168; https://doi.org/10.3390/jcs7040168 - 17 Apr 2023
Cited by 6 | Viewed by 3149
Abstract
In 2020, we published a review on the study of semi-crystalline thermoplastic polyurethane elastomers and composites based on the shape memory effect. The shape recovery ability of such polymers is determined by their sensitivity to temperature, moisture, and magnetic or electric fields, which [...] Read more.
In 2020, we published a review on the study of semi-crystalline thermoplastic polyurethane elastomers and composites based on the shape memory effect. The shape recovery ability of such polymers is determined by their sensitivity to temperature, moisture, and magnetic or electric fields, which in turn are dependent on the chemical properties and composition of the matrix and the nanofiller. Nanocellulose is a type of nanomaterial with high strength, high specific surface area and high surface energy. Additionally, it is nontoxic, biocompatible, environmentally friendly, and can be extracted from biomass resources. Thanks to these properties, nanocellulose can be used to enhance the mechanical properties of polymer matrices with shape memory effect and as a switching element of shape memory. This review discusses the methods for producing and properties of nanocellulose-based thermo-, moisture-, and pH-sensitive polyurethane composites. The synergistic effect of nanocellulose and carbon nanofillers and possible applications of nanocellulose-based thermoplastic polyurethane biocomposites with shape memory effect are discussed. A brief description of nanocellulose terminology is also given, along with the structure of shape memory thermoplastic polyurethanes. There is significant interest in such materials for three primary reasons: the possibility of creating a new generation of biomaterials, improving the environmental friendliness of existing materials, and exploiting the natural renewability of cellulose sources. Full article
(This article belongs to the Section Biocomposites)
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14 pages, 4483 KiB  
Article
α-Manganese Dioxide (α-MnO2) Coated with Polyaniline (PANI) and Reduced Graphene Oxide (rGO)-Based Nanocomposite for Supercapacitor Application
by Pranoti H. Patil, Vidya V. Kulkarni, Tukaram D. Dongale and Sushilkumar A. Jadhav
J. Compos. Sci. 2023, 7(4), 167; https://doi.org/10.3390/jcs7040167 - 16 Apr 2023
Cited by 17 | Viewed by 1686
Abstract
This work reports the preparation and testing of a composite material composed of α-Manganese dioxide (α-MnO2) coated with polyaniline (PANI) and reduced graphene oxide (rGO) for supercapacitor application. The structure and morphology of the materials were characterized by using X-ray diffraction [...] Read more.
This work reports the preparation and testing of a composite material composed of α-Manganese dioxide (α-MnO2) coated with polyaniline (PANI) and reduced graphene oxide (rGO) for supercapacitor application. The structure and morphology of the materials were characterized by using X-ray diffraction (XRD) analysis, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), thermogravimetric analysis (TGA) and Raman spectroscopy. The electrochemical performances of the materials were investigated by using cyclic voltammetry (CV), Galvanostatic charge–discharge (GCD), cyclic stability and electrochemical impedance spectroscopy (EIS). The α-MnO2-coated PANI/rGO nanocomposite exhibited a specific capacitance of 261 F g−1 at the scan rate of 5 mV s−1 with 75% capacitance retention after 2000 cycles at 5 A g−1. It showed a specific energy of 11 W h kg−1 and specific power of 1250 W kg−1. Full article
(This article belongs to the Special Issue Nanocomposites for Supercapacitor Application)
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19 pages, 3754 KiB  
Review
Green Nanocomposite Electrodes/Electrolytes for Microbial Fuel Cells—Cutting-Edge Technology
by Ayesha Kausar, Ishaq Ahmad, Tingkai Zhao, Malik Maaza and Patrizia Bocchetta
J. Compos. Sci. 2023, 7(4), 166; https://doi.org/10.3390/jcs7040166 - 15 Apr 2023
Cited by 1 | Viewed by 1938
Abstract
Fuel cell efficiency can be improved by using progressive electrodes and electrolytes. Green nanomaterials and green technologies have been explored for the manufacturing of high-performance electrode and electrolyte materials for fuel cells. Platinum-based electrodes have been replaced with green materials and nanocomposites using [...] Read more.
Fuel cell efficiency can be improved by using progressive electrodes and electrolytes. Green nanomaterials and green technologies have been explored for the manufacturing of high-performance electrode and electrolyte materials for fuel cells. Platinum-based electrodes have been replaced with green materials and nanocomposites using green fabrication approaches to attain environmentally friendly fuel cells. In this regard, ecological and sustainable electrode- and electrolyte-based membrane electrode assemblies have also been designed. Moreover, green nanocomposites have been applied to form the fuel cell electrolyte membranes. Among fuel cells, microbial fuel cells have gained research attention for the incorporation of green and sustainable materials. Hence, this review essentially focuses on the potential of green nanocomposites as fuel cell electrode and electrolyte materials and application of green synthesis techniques to attain these materials. The design of and interactions with nanocomposites have led to synergistic effects on the morphology, impedance, resistance, power density, current density, electrochemical features, proton conductivity, and overall efficiency. Moreover, we deliberate the future significance and challenges of the application of green nanocomposites in electrodes and electrolytes to attain efficient fuel cells. Full article
(This article belongs to the Special Issue Feature Papers in Journal of Composites Science in 2023)
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18 pages, 3232 KiB  
Review
Review on Molecular Dynamics Simulations of Effects of Carbon Nanotubes (CNTs) on Electrical and Thermal Conductivities of CNT-Modified Polymeric Composites
by Lida Najmi and Zhong Hu
J. Compos. Sci. 2023, 7(4), 165; https://doi.org/10.3390/jcs7040165 - 15 Apr 2023
Cited by 15 | Viewed by 1747
Abstract
Due to the unique properties of carbon nanotubes (CNTs), the electrical and thermal conductivity of CNT-modified polymeric composites (CNTMPCs) can be manipulated and depend on several factors. There are many factors that affect the thermal and electrical conductivity of CNTs and CNTMPCs, such [...] Read more.
Due to the unique properties of carbon nanotubes (CNTs), the electrical and thermal conductivity of CNT-modified polymeric composites (CNTMPCs) can be manipulated and depend on several factors. There are many factors that affect the thermal and electrical conductivity of CNTs and CNTMPCs, such as chirality, length, type of CNTs, fabrication, surface treatment, matrix and interfacial interaction between the matrix and reinforcement (CNTs). This paper reviews the research on molecular dynamics (MD) simulations of the effects of some factors affecting the thermal and electrical conductivity of CNTs and CNTMPCs. First, the chirality dependence of the thermal and electrical conductivity of single-walled carbon nanotubes (SWNTs) was analyzed. The effect of chirality on the conductivity of short-length CNTs is greater than that of long-length CNTs, and the larger the chiral angle, the greater the conductivity of the CNTs. Furthermore, the thermal and electrical conductivity of the zigzag CNTs is smaller than that of the armchair one. Therefore, as the tube aspect ratio becomes longer and conductivity increases, while the effect of chirality on the conductivity decreases. In addition, hydrogen bonding affects the electrical and thermal conductivity of the CNTMPCs. The modeling of SWNTs shows that the thermal and electrical conductivity increases significantly with increasing overlap length. MD simulations can be effectively used to design highly conductive CNTMPCs with appropriated thermal and electrical properties. Since there are too many factors affecting the thermal and electrical conductivity of CNTMPCs, this paper only reviews the effects of limited factors on the thermal and electrical conductivity of CNTs and CNTMPCs based on MD simulations, and further detailed studies are required. Full article
(This article belongs to the Section Polymer Composites)
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18 pages, 1222 KiB  
Article
Biodegradation of Aqueous Superabsorbents: Kinetic Assessment Using Biological Oxygen Demand Analysis
by Andrey V. Smagin, Nadezhda B. Sadovnikova and Viktor I. Budnikov
J. Compos. Sci. 2023, 7(4), 164; https://doi.org/10.3390/jcs7040164 - 14 Apr 2023
Cited by 2 | Viewed by 1289
Abstract
Biodegradation is an important environmental factor controlling the effectiveness of aqueous superabsorbents for soil conditioning. The purpose of the study is to quantify this process using biological oxygen demand (BOD) analysis of composite superabsorbents with an acrylic polymer matrix, amphiphilic fillers (humates, peat) [...] Read more.
Biodegradation is an important environmental factor controlling the effectiveness of aqueous superabsorbents for soil conditioning. The purpose of the study is to quantify this process using biological oxygen demand (BOD) analysis of composite superabsorbents with an acrylic polymer matrix, amphiphilic fillers (humates, peat) and silver ions as an inhibitor of biological activity. A simple kinetic model of BOD is proposed for standardization of the analysis and calculation of polymer half-life after their long-term (60–120 days) incubation in the VELP BOD analyzer (Italy) with automatic control. The half-life of pure hydrogels pre-swollen in distilled water (1:100) at 30 °C varied from 0.8 ± 0.2 to 2.4 ± 1.6 years. The addition of water extract from compost sharply enhances the biodegradation, lowering the half-life up to 40–60 days. Doses of 0.1–1% silver in a polymer matrix or 10–100 ppm in swollen hydrogels increase their half-life by 5–20 times. The discussion part questions the traditional division of aqua superabsorbents into “biodegradable” and “non-biodegradable”, and also analyzes the main advantages and disadvantages of the new methodology for their BOD analysis. The results may be of interest to a wide range of specialists from chemical technologists and biochemists to environmental engineers. Full article
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12 pages, 7001 KiB  
Article
Durability of High-Density Polyethylene (HDPE)- and Polypropylene (PP)-Based Wood-Plastic Composites—Part 1: Mechanical Properties of the Composite Materials
by Halim Hamid Redhwi, Mohammad Nahid Siddiqui, Anthony L. Andrady, Sarfaraz A. Furquan and Syed Hussain
J. Compos. Sci. 2023, 7(4), 163; https://doi.org/10.3390/jcs7040163 - 13 Apr 2023
Cited by 1 | Viewed by 2707
Abstract
Wood-plastic composites (WPCs) have shown exceptional promise as a building material, especially for outdoor uses. Using renewable wood fiber as the reinforcing filler in WPCs increases the material’s environmental sustainability. While virgin commodity thermoplastics are primarily used in these composites, using post-consumer plastic [...] Read more.
Wood-plastic composites (WPCs) have shown exceptional promise as a building material, especially for outdoor uses. Using renewable wood fiber as the reinforcing filler in WPCs increases the material’s environmental sustainability. While virgin commodity thermoplastics are primarily used in these composites, using post-consumer plastic further contributes to their sustainability. While they are beginning to be used in the Gulf countries, information on their performance, especially durability under harsh desert climates, is sparse. The present investigation on WPCs is based on the two most popularly used thermoplastics in WPCs, virgin high-density polyethylene (HDPE) and polypropylene (PP), with the wood content varying between 0 and 36 wt. %. These were prepared with melt processing from a masterbatch and characterized primarily using thermal methods and tensile properties of their injection molded test pieces. Variations in tensile properties, especially the tensile modulus (MPa), the tensile strength (MPa), and the ultimate extensibility (%) of the composite samples were investigated to determine an optimal wood-fiber loading. For either polymer type, exceeding 27 weight percent of wood fiber resulted in unacceptably low ultimate extensibility of the material. Full article
(This article belongs to the Special Issue Wood-Polymer Composites)
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16 pages, 38453 KiB  
Article
Composite Plastic Hybrid for Automotive Front Bumper Beam
by Shada Bennbaia, Elsadig Mahdi, Galal Abdella and Aamir Dean
J. Compos. Sci. 2023, 7(4), 162; https://doi.org/10.3390/jcs7040162 - 12 Apr 2023
Cited by 4 | Viewed by 2424
Abstract
The bumper beam is a crucial component of the automobile bumper system, responsible for absorbing impact energy and enhancing the safety of passengers during collisions. This paper presents the design and experimental analysis of a 3D-printed composite–plastic hybrid light structure, designed as a [...] Read more.
The bumper beam is a crucial component of the automobile bumper system, responsible for absorbing impact energy and enhancing the safety of passengers during collisions. This paper presents the design and experimental analysis of a 3D-printed composite–plastic hybrid light structure, designed as a collapsible energy absorber. Exploratory testing was conducted using low-impact tests to investigate the failure mechanism and energy absorption capacity of a spiral structure. The design process involved optimizing the spiral diameter by testing specimens with varying diameters between 0.5 cm and 2.5 cm, while keeping other geometric parameters constant. The study employed three types of 3D composite structures, including printed thermoplastic, printed thermoplastic reinforced with Kevlar fiber composite, and printed thermoplastic filled with foam. The thermoplastic–foam composite with nine spirals (diameter = 0.97 cm) yielded the best results. The new design demonstrated high energy absorption capacity and a controlled and progressive failure mechanism, making it a suitable candidate for energy absorption applications. Full article
(This article belongs to the Section Polymer Composites)
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25 pages, 4781 KiB  
Review
Aluminum Alloy Reinforced with Agro-Waste, and Eggshell as Viable Material for Wind Turbine Blade to Annex Potential Wind Energy: A Review
by Imhade P. Okokpujie and Lagouge K. Tartibu
J. Compos. Sci. 2023, 7(4), 161; https://doi.org/10.3390/jcs7040161 - 12 Apr 2023
Cited by 4 | Viewed by 2313
Abstract
The most important part of the wind turbine is the blade. From existing studies, it has been concluded that most wind turbine blades have a high rate of failure during operation due to fatigue, because of a lack of proper material selection processes. [...] Read more.
The most important part of the wind turbine is the blade. From existing studies, it has been concluded that most wind turbine blades have a high rate of failure during operation due to fatigue, because of a lack of proper material selection processes. Materials such as fiberglass, wood, aluminum, and steel have been used but have not been able to qualify as sustainable materials. Therefore, this study focuses on the review of existing materials employed for developing metal matrix composites as ecological materials to produce wind blades. This study discusses the application of aluminium, silicon, and magnesium metal matrix alloys and the implementation of agro-waste materials (coconut rice, coconut shell, rice husk ash, and sugar Bagasse ash) and eggshell as reinforcement particulates for metal matrix composites for developing wind blades. The study also reviews the method of production of matrix composites. From the results obtained via the review, it is clear that the application of eggshells assists as a binding element for proper mixture, and the combination of Al–Si–Mg alloy with coconut rice and shell improves the strength of the material, since wind blades need durable materials and ductility due to their aerodynamic shape to convert enough energy from the wind. Full article
(This article belongs to the Section Composites Manufacturing and Processing)
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13 pages, 3129 KiB  
Article
PVB Nanocomposites as Energy Directors in Ultrasonic Welding of Epoxy Composites
by Fabrizia Cilento, Alessio Bassano, Luigi Sorrentino, Alfonso Martone, Michele Giordano and Barbara Palmieri
J. Compos. Sci. 2023, 7(4), 160; https://doi.org/10.3390/jcs7040160 - 12 Apr 2023
Cited by 3 | Viewed by 1370
Abstract
Ultrasonic welding (UW) is a well-established technique for joining thermoplastic composites and has recently been utilized in the aerospace and automotive industries. In the case of thermoset composites (TSCs), a polymer-based material placed at the welding interface called an energy director (ED) is [...] Read more.
Ultrasonic welding (UW) is a well-established technique for joining thermoplastic composites and has recently been utilized in the aerospace and automotive industries. In the case of thermoset composites (TSCs), a polymer-based material placed at the welding interface called an energy director (ED) is required. The choice of the coupling layer material is linked to several requirements, such as processing temperature, high adhesion to the thermoset composites (TSCs) adherend and mechanical strength of the resulting welded joints. In this work, the authors investigated the possibility of using Poly-vinyl-butyral (PVB) reinforced with graphite nanoplatelets (GNPs) as a coupling layer in the UW of TSC adherents. The effect of GNPs aspect ratio and content on the weldability of carbon fiber-reinforced plastics (CFRP) has been investigated. PVB/GNPs nanocomposites with different filler contents (from 0.5 wt% to 2 wt%) and different aspect ratios (100 and 2100) have been fabricated. The influence of the viscoelastic properties of the flat EDs on weldability has been assessed. Finally, an improvement of lap shear strength (LSS) of 80% was found for nanocomposites with 0.5 wt% of high-aspect-ratio GNPs with respect to neat PVB. The use of high damping nanocomposites as coupling materials for TSCs paves the way for a new generation of EDs in UW. Full article
(This article belongs to the Topic Advanced Carbon Fiber Reinforced Composite Materials)
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20 pages, 8238 KiB  
Article
Mechanical and Tribological Behavior of LM26/SiC/Ni-Gr Hybrid Composites
by Suyash Y. Pawar, Julfikar Haider, Giuseppe Pintaude, Santhosh Mozhuguan Sekar, Vikram Kolhe, Kailas Chandratre, Sandipkumar Sonawane and Parmeshwar Ritapure
J. Compos. Sci. 2023, 7(4), 159; https://doi.org/10.3390/jcs7040159 - 12 Apr 2023
Cited by 1 | Viewed by 2090
Abstract
The study evaluates the mechanical and wear properties of LM26 alloy and its hybrid composites with silicon carbide (SiC) and nickel-coated graphite (Ni-Gr). LM26 aluminum alloy is generally known for its high strength, wear, and corrosion resistance compared to similar materials such as [...] Read more.
The study evaluates the mechanical and wear properties of LM26 alloy and its hybrid composites with silicon carbide (SiC) and nickel-coated graphite (Ni-Gr). LM26 aluminum alloy is generally known for its high strength, wear, and corrosion resistance compared to similar materials such as zinc and magnesium. The effect of Ni-Gr was studied, with 2 wt.% was found to provide the best mechanical properties. LM26 composites reinforced with varying percentages of SiC (0 to 30 wt.%) showed the best properties at 20 wt.% reinforcement after fabrication using a bottom pouring type stir casting setup (Two step feeding method). Evaluation of five hybrid LM26 composites through tensile strength, elongation, hardness, impact, porosity, and thermal studies showed that the LM26/2 wt.% Ni-Gr/20 wt.% SiC configuration showed the best filler composition for improved strength. Sliding wear evaluation using experimental and Taguchi analysis was performed at different configurations to identify the best wear resistance. Microstructure studies showed the presence of Ni-Gr particles forming coatings and temperature playing a significant role in the progression of the wear rate. Furthermore, the hybrid composite with 20% SiC and 2% Ni-Gr reinforcement showed the best wear resistance. Full article
(This article belongs to the Section Composites Modelling and Characterization)
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13 pages, 4585 KiB  
Article
Surface Optimization of Components Obtained by Fused Deposition Modeling for Air-Plasma-Sprayed Ceramic Coatings
by Antonio Formisano, Luca Boccarusso and Antonio Langella
J. Compos. Sci. 2023, 7(4), 158; https://doi.org/10.3390/jcs7040158 - 11 Apr 2023
Viewed by 1098
Abstract
Additive manufacturing is an emerging disruptive 3D printing technology that is stimulating innovations in design and engineering, materials, and manufacturing thanks to the prospects of reducing cost and waste and increasing efficiency; in doing so, it presents the potential to have marked industrial, [...] Read more.
Additive manufacturing is an emerging disruptive 3D printing technology that is stimulating innovations in design and engineering, materials, and manufacturing thanks to the prospects of reducing cost and waste and increasing efficiency; in doing so, it presents the potential to have marked industrial, economic, and societal impacts. Thermoplastic polymers show some ideal characteristics for the most common additive manufacturing methods, and this aids in the improvement of the design accuracy and reliability and makes inroads for the customized manufacturing of high-design-flexibility polymer parts. Despite this, this material family is strongly sensitive to temperature, and one of the viable ways of limiting this weak point is surface coating with thermal barriers. The focus of this work was the optimization of an additive manufacturing process for producing thermoplastic components and to improve the adhesion of a thermal barrier coating on their surface. In detail, flat plate specimens of ULTEM 1010 were obtained by the fused deposition modeling technique by varying two significant surface parameters, the enhanced visible rasters and the visible raster air gap; then, their surfaces were covered by a thin ceramic coating by an air plasma spray system. A micro-geometric analysis that was conducted using a confocal microscope and the coating thickness measurements highlighted that a global larger roughness value, the presence of more flat peaks with a large area, and the complexity of the texture can be considered as supporting factors for improving the mechanical gripping and allowing a uniform adhesion of the coating powders on the thermoplastic substrate. Full article
(This article belongs to the Section Polymer Composites)
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16 pages, 4716 KiB  
Article
Extrusion-Based Additively Manufactured PAEK and PAEK/CF Polymer Composites Performance: Role of Process Parameters on Strength, Toughness and Deflection at Failure
by S. Sharafi, M. H. Santare, J. Gerdes and S. G. Advani
J. Compos. Sci. 2023, 7(4), 157; https://doi.org/10.3390/jcs7040157 - 11 Apr 2023
Viewed by 1474
Abstract
Poly aryl-ether-ketone (PAEK) belongs to a family of high-performance semicrystalline polymers exhibiting outstanding material properties at high temperatures, making them suitable candidates for metallic part replacement in different industries such as aviation, oil and gas, chemical, and biomedical. Fused filament fabrication is an [...] Read more.
Poly aryl-ether-ketone (PAEK) belongs to a family of high-performance semicrystalline polymers exhibiting outstanding material properties at high temperatures, making them suitable candidates for metallic part replacement in different industries such as aviation, oil and gas, chemical, and biomedical. Fused filament fabrication is an additive manufacturing (AM) method that can be used to produce intricate PAEK and PAEK composite parts and to tailor their mechanical properties such as stiffness, strength and deflection at failure. In this work, we present a methodology to identify the layer design and process parameters that will have the highest potential to affect the mechanical properties of additively manufactured parts, using our previously developed multiscale modeling framework. Five samples for each of the ten identified process conditions were fabricated using a Roboze-Argo 500 version 2 with heated chamber and dual extruder nozzle. The manufactured PAEK and PAEK/carbon fiber samples were tested until failure in an Instron, using a video extensometer system. Each sample was prepared with a speckle pattern for post analysis using digital image correlation (DIC) to measure the strain and displacement over its entire surface. The raster angle and the presence of fibers had the largest influence on the mechanical properties of the AM manufactured parts, and the resulting properties were comparable to the mechanical properties of injection molded parts. Full article
(This article belongs to the Special Issue Additive Manufacturing of Advanced Composites)
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21 pages, 4296 KiB  
Article
Highly Selective Polyene-Polyyne Resistive Gas Sensors: Response Tuning by Low-Energy Ion Irradiation
by Ilya A. Zavidovskiy, Oleg A. Streletskiy, Islam F. Nuriahmetov, Olesya Yu. Nishchak, Natalya F. Savchenko, Andrey A. Tatarintsev and Alexander V. Pavlikov
J. Compos. Sci. 2023, 7(4), 156; https://doi.org/10.3390/jcs7040156 - 11 Apr 2023
Cited by 9 | Viewed by 1946
Abstract
The formation of polyene-polyyne-based nanocomposites by dehydrohalogenation of the drop-cast-deposited polyvinylidene fluoride, assessment and ion-induced tailoring of their gas sensing properties are reported. The investigated structure was analyzed by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy, transmission electron microscopy and Fourier-transform infrared spectroscopy, [...] Read more.
The formation of polyene-polyyne-based nanocomposites by dehydrohalogenation of the drop-cast-deposited polyvinylidene fluoride, assessment and ion-induced tailoring of their gas sensing properties are reported. The investigated structure was analyzed by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy, transmission electron microscopy and Fourier-transform infrared spectroscopy, revealing the thickness-dependent incomplete dehydrofluorination of the structure and its porosity induced by KOH treatment. The polyene-polyyne structures modified by low-energy Ar+ were studied by SEM and Raman spectroscopy, which showed the morphology variation, the shortening of chains and the graphitization of samples. The resistive gas sensing properties of the samples were analyzed at room temperature, revealing selective sensing of ammonia vapor by non-irradiated sample and the enhancement of the sensing properties for ethanol and water vapor after ion irradiation. With the ion dose enlargement, the change in the sensing response from electrical conductivity increase to decrease was observed for ammonia and ethanol, allowing us to discuss the origin and tunability of the sensing mechanism of the samples. Full article
(This article belongs to the Special Issue Radiation Effects in Polymer Hybrids)
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16 pages, 34041 KiB  
Article
Impacts of Structure-Directing Agents on the Synthesis of Cu3Mo2O9 for Flexible Lignin-Based Supercapacitor Electrodes
by Siddhi Mehta, Sangeetha Kumaravel, Swarn Jha, Matthew Yen, Subrata Kundu and Hong Liang
J. Compos. Sci. 2023, 7(4), 155; https://doi.org/10.3390/jcs7040155 - 11 Apr 2023
Cited by 3 | Viewed by 1668
Abstract
Due to demands for sustainability, the interest in energy storage devices constructed from green materials has increased immensely. These devices currently have yet to be satisfactory. Issues include high production costs and toxicity, limited dependability, and subpar electrochemical performance. In this research, low-cost, [...] Read more.
Due to demands for sustainability, the interest in energy storage devices constructed from green materials has increased immensely. These devices currently have yet to be satisfactory. Issues include high production costs and toxicity, limited dependability, and subpar electrochemical performance. In this research, low-cost, plant-based electroactive Cu3Mo2O9 materials were synthesized via co-precipitation followed by an annealing method using two different structure-directing agents, i.e., the commonly used surfactant cetyltrimethylammonium bromide (CTAB) and the biomolecule deoxyribonucleic acid (DNA) as a greener alternative, and these materials were studied for the first time. Further, the Cu3Mo2O9 nanoparticles developed using CTAB and DNA were integrated into the lignin matrix and studied as flexible electrodes for supercapacitor application. Here, the morphological advantages of the nanorods and nanosheets formed by varying the synthesis methods and their effects during supercapacitor studies were studied in detail. After 1200 cycles, the Al/lig-Cu3Mo2O9@DNA supercapacitor exhibited higher capacitive performance when compared to the Al/lig-Cu3Mo2O9@CTAB supercapacitor. The Al/Lig-Cu3Mo2O9@DNA supercapacitor had an initial specific capacitance of 404.64 mF g−1 with a ~70% retention, while the Al/Lig-Cu3Mo2O9@CTAB supercapacitor had an initial specific capacitance of 309.59 mF g−1 with a ~50% retention. This study offers a new approach to creating scalable, low-cost, green composite CuMoO4-based electrodes for flexible supercapacitors. Full article
(This article belongs to the Section Composites Applications)
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1 pages, 187 KiB  
Correction
Correction: Luhar et al. Challenges and Impacts of COVID-19 Pandemic on Global Waste Management Systems: A Review. J. Compos. Sci. 2022, 6, 271
by Ismail Luhar, Salmabanu Luhar and Mohd Mustafa Al Bakri Abdullah
J. Compos. Sci. 2023, 7(4), 154; https://doi.org/10.3390/jcs7040154 - 11 Apr 2023
Viewed by 529
Abstract
In the published publication [...] Full article
14 pages, 3672 KiB  
Article
High-Pressure FDM 3D Printing in Nitrogen [Inert Gas] and Improved Mechanical Performance of Printed Components
by Yousuf Pasha Shaik, Jens Schuster and Naresh Kumar Naidu
J. Compos. Sci. 2023, 7(4), 153; https://doi.org/10.3390/jcs7040153 - 10 Apr 2023
Viewed by 1905
Abstract
Fundamentally, the mechanical characteristics of 3D-printed polymeric objects are determined by their fabrication circumstances. In contrast to traditional polymer processing processes, additive manufacturing requires no pressure during layer consolidation. This study looks at how a high-pressure autoclave chamber without oxygen affects layer consolidation [...] Read more.
Fundamentally, the mechanical characteristics of 3D-printed polymeric objects are determined by their fabrication circumstances. In contrast to traditional polymer processing processes, additive manufacturing requires no pressure during layer consolidation. This study looks at how a high-pressure autoclave chamber without oxygen affects layer consolidation throughout the fused deposition modelling process, as well as the mechanical qualities of the products. To attain high strength qualities for 3D-printed components such as injection-molded specimens, an experimental setup consisting of a 3D printer incorporated within a bespoke autoclave was designed. The autoclave can withstand pressures of up to 135 bar and temperatures of up to 185 °C. PLA 3D printing was carried out in the autoclave at two different pressures in compressed air and nitrogen atmospheres: 0 bar and 5 bar. Furthermore, injection molding was done using the same PLA material. Tensile, flexural, and Charpy tests were carried out on samples that were 3D printed and injection molded. In nitrogen, oxidation of the environment was prevented by autoclave preheating before printing, and autoclave pressure during printing considerably promotes layer consolidation. This imprinted mechanical strength on the 3D-printed items, which are virtually as strong as injection-molded components. Full article
(This article belongs to the Special Issue 3D Printing Composites)
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19 pages, 5204 KiB  
Article
Evaluation of Hybrid Fiber Multiscale Polymer Composites for Structural Confinement under Cyclic Axial Compressive Loading
by Lakshmi Joseph, Mini K. Madhavan, Karingamanna Jayanarayanan and Alessandro Pegoretti
J. Compos. Sci. 2023, 7(4), 152; https://doi.org/10.3390/jcs7040152 - 09 Apr 2023
Cited by 1 | Viewed by 1539
Abstract
Fiber reinforced polymer (FRP) confinement is recognized as the most promising technique for the strengthening and retrofitting of concrete structures. In order to enhance the performance of conventional epoxy-based FRP composites, nano filler modification of the epoxy matrix was implemented in the current [...] Read more.
Fiber reinforced polymer (FRP) confinement is recognized as the most promising technique for the strengthening and retrofitting of concrete structures. In order to enhance the performance of conventional epoxy-based FRP composites, nano filler modification of the epoxy matrix was implemented in the current study. In particular, the cyclic loading response of standard concrete specimens externally confined by epoxy-based natural and hybrid fiber reinforced polymer systems was investigated. The confinements were realized with sisal fiber reinforced polymer (SFRP) and hybrid sisal basalt fiber reinforced polymer (HSBFRP). Moreover, the effects of multiwalled carbon nanotubes (MWCNT) were also investigated. Three different specimen sets were considered for study: (i) unconfined specimens, (ii) epoxy-based FRP confined specimens and (iii) MWCNT incorporated epoxy-based FRP confined specimens. The specimens were tested in repeated compressive mode in loading-unloading cycles at increasing displacement levels. The test results revealed that FRP wrapping could enhance the mechanical behavior of unconfined columns in terms of strength and ductility. Moreover, it was evident that the mechanical properties of the epoxy matrix were enhanced by MWCNT incorporation. The developed epoxy-based FRP confinement containing MWCNT ensures improvement in axial strength by 71% when compared with unconfined specimens. The epoxy-based FRP confinement, with and without MWCNT, exhibited a high strain redistribution behavior around the concrete core. In comparison to the unconfined specimens, the confinement could increase the sustained axial strain from 0.6 to 1.4% using epoxy-based FRP confinement and to 1.6% with MWCNT incorporated epoxy-based FRP confinement. Further, an empirical model was developed to predict the ultimate axial stress of concrete columns confined externally with FRP jackets. The ultimate compressive strength obtained from the experimental study was compared with the proposed model, and the observed deviation was lower than 1%. Full article
(This article belongs to the Section Polymer Composites)
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13 pages, 5662 KiB  
Article
Enhancing Mechanical Properties of 3D-Printed PLAs via Optimization Process and Statistical Modeling
by Ali Shahrjerdi, Mojtaba Karamimoghadam and Mahdi Bodaghi
J. Compos. Sci. 2023, 7(4), 151; https://doi.org/10.3390/jcs7040151 - 09 Apr 2023
Cited by 4 | Viewed by 1430
Abstract
This paper investigates the optimization of 3D printing by 1.75 mm filaments of poly-lactic acid (PLA) materials. The samples are printed separately and glued together to join the tensile device for the failure load and checking the surface roughness. The printing method in [...] Read more.
This paper investigates the optimization of 3D printing by 1.75 mm filaments of poly-lactic acid (PLA) materials. The samples are printed separately and glued together to join the tensile device for the failure load and checking the surface roughness. The printing method in this research is Fused Deposition Modeling (FDM), in which the parameters of Infill Percentage (IP), Extruder Temperature (ET), and Layer Thickness (LT) are considered variable parameters for the 3D printer, and according to the Design of Experiments (DOE), a total of 20 experiments are designed. The parametric range is considered to be 15–55% for IP, 190–250 °C for ET, and 0.15–0.35 mm for LT. The optimization model is conducted according to the Response Surface Method (RSM), in which the ANOVA and plot tables are examined. Moreover, the samples’ maximum failure load, weight, fabrication time, and surface roughness are considered output responses. Statistical modeling shows that by increasing the IP and setting the ET at 220 °C, the failure load of the samples increases, and the maximum failure load reaches 1218 N. The weight and fabrication time of the specimen are optimized at the same time to achieve maximum failure load with less surface roughness. By comparing the predicted and actual output for the optimum samples, the percentage error for all results is less than 5%. The developed optimization method is revealed to be accurate and reliable for FDM 3D printing of PLAs. Full article
(This article belongs to the Special Issue Feature Papers in Journal of Composites Science in 2023)
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25 pages, 21888 KiB  
Article
Effect of Biobased SiO2 on the Morphological, Thermal, Mechanical, Rheological, and Permeability Properties of PLLA/PEG/SiO2 Biocomposites
by Johanna Morales, Rose Mary Michell, Alicia Sommer-Márquez and Denis Rodrigue
J. Compos. Sci. 2023, 7(4), 150; https://doi.org/10.3390/jcs7040150 - 08 Apr 2023
Cited by 3 | Viewed by 1300
Abstract
Nowadays, companies and researchers are concerned about the negative consequences of using synthetic polymers and direct their efforts to create new alternatives such as biocomposites. This study investigated the effect of biobased SiO2 on the properties of poly(L-lactic acid)/SiO2 (PLLA/SiO2 [...] Read more.
Nowadays, companies and researchers are concerned about the negative consequences of using synthetic polymers and direct their efforts to create new alternatives such as biocomposites. This study investigated the effect of biobased SiO2 on the properties of poly(L-lactic acid)/SiO2 (PLLA/SiO2) and poly(L-lactic acid)/SiO2/poly(ethylene glycol) (PLLA/SiO2/PEG) composites. The SiO2 was obtained from rice husk incineration and mixed with PLLA at various concentrations (5, 10, and 15 wt.%) via melt extrusion before compression molding. Furthermore, PLLA/SiO2/PEG composites with various PEG concentrations (0, 3, 5, and 10 wt.%) with 10 wt.% SiO2 were produced. The sample morphology was studied by scanning electron microscopy (SEM) to analyze the dispersion/adhesion of SiO2 in the polymer matrix and differential scanning calorimetry (DSC) was used under isothermal and non-isothermal conditions to study the thermal properties of the samples, which was complemented by thermal stability study using thermogravimetric analysis (TGA). Rheological analysis was performed to investigate the viscoelastic behavior of the composites in the melt state. At the same time, tensile mechanical properties were obtained at room temperature to determine their properties in the solid state. DSC and X-ray diffraction analysis (XRD) were combined to determine the crystalline state of the samples. Finally, gas permeation measurements were performed using a variable pressure (constant volume) method to analyze the permeability of different gases (CO2, CH4, O2, and H2). The results showed that SiO2 decreased the PLLA chain mobility, slowing the crystallization process and lowering the gas permeability while increasing Young’s modulus, thermal stability, and viscosity. However, PEG addition increased the crystallization rate compared to the neat PLLA (+40%), and its elongation at break (+26%), leading to more flexible/ductile samples. Due to improved silica dispersion and PLLA chain mobility, the material’s viscosity and gas permeability (+50%) were also improved with PEG addition. This research uses material considered as waste to improve the properties of PLA, obtaining a material with the potential to be used for packaging. Full article
(This article belongs to the Section Biocomposites)
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19 pages, 22536 KiB  
Article
Experimental Investigation of Mechanical Property and Wear Behaviour of T6 Treated A356 Alloy with Minor Addition of Copper and Zinc
by Nithesh Kashimat, Sathyashankara Sharma, Rajesh Nayak, Karthik Birur Manjunathaiah, Manjunath Shettar and Gowrishankar Mandya Chennegowda
J. Compos. Sci. 2023, 7(4), 149; https://doi.org/10.3390/jcs7040149 - 07 Apr 2023
Cited by 2 | Viewed by 1451
Abstract
The present study examines the effect of trace additions of copper (up to 1 wt.%) and zinc (0.5 wt.%) as the alloying elements on the microstructure, hardness, and wear behaviour of T6 treated A356 (Al-7Si) alloy. Wear tests were conducted using a pin-on-disc [...] Read more.
The present study examines the effect of trace additions of copper (up to 1 wt.%) and zinc (0.5 wt.%) as the alloying elements on the microstructure, hardness, and wear behaviour of T6 treated A356 (Al-7Si) alloy. Wear tests were conducted using a pin-on-disc tribometer under a constant sliding speed of 200 RPM, varying applied load (20–40 N), and sliding distance (0–3000 m) to determine the wear rate and the coefficient of friction. The results indicated a minimum of 1 wt.% of copper was required to form the Al2Cu intermetallic phase, resulting in a finer grain structure and improved hardness. However, the role of zinc as a trace element was not observed on the microstructure; the observed changes may be the combined effect of copper and zinc as a whole. The highest hardness of 107 VHN (98% increase) was achieved with 1 wt.% copper addition during peak aging at 100 °C. Also, wear tests showed that adding 1 wt.% copper to the A356 alloy and a 100 °C precipitation hardening (T6) treatment improved the wear resistance by 150–182% with a reduced coefficient of friction. Full article
(This article belongs to the Special Issue Advanced Polymeric Composites and Hybrid Materials)
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26 pages, 9876 KiB  
Review
Self-Healing Nanocomposites—Advancements and Aerospace Applications
by Ayesha Kausar, Ishaq Ahmad, Malik Maaza and Patrizia Bocchetta
J. Compos. Sci. 2023, 7(4), 148; https://doi.org/10.3390/jcs7040148 - 07 Apr 2023
Cited by 4 | Viewed by 4735
Abstract
Self-healing polymers and nanocomposites form an important class of responsive materials. These materials have the capability to reversibly heal their damage. For aerospace applications, thermosets and thermoplastic polymers have been reinforced with nanocarbon nanoparticles for self-healing of structural damage. This review comprehends the [...] Read more.
Self-healing polymers and nanocomposites form an important class of responsive materials. These materials have the capability to reversibly heal their damage. For aerospace applications, thermosets and thermoplastic polymers have been reinforced with nanocarbon nanoparticles for self-healing of structural damage. This review comprehends the use of self-healing nanocomposites in the aerospace sector. The self-healing behavior of the nanocomposites depends on factors such as microphase separation, matrix–nanofiller interactions and inter-diffusion of polymer–nanofiller. Moreover, self-healing can be achieved through healing agents such as nanocapsules and nanocarbon nanoparticles. The mechanism of self-healing has been found to operate via physical or chemical interactions. Self-healing nanocomposites have been used to design structural components, panels, laminates, membranes, coatings, etc., to recover the damage to space materials. Future research must emphasize the design of new high-performance self-healing polymeric nanocomposites for aerospace structures. Full article
(This article belongs to the Special Issue Feature Papers in Journal of Composites Science in 2023)
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24 pages, 5338 KiB  
Article
Effect of Nanoparticles and Their Anisometry on Adhesion and Strength in Hybrid Carbon-Fiber-Reinforced Epoxy Nanocomposites
by Sergey O. Ilyin and Sergey V. Kotomin
J. Compos. Sci. 2023, 7(4), 147; https://doi.org/10.3390/jcs7040147 - 07 Apr 2023
Cited by 5 | Viewed by 1875
Abstract
Carbon-fiber-reinforced plastics are composite materials with record-high specific strength, which depends on the efficiency of stress redistribution between the reinforcing fibers by the polymer matrix. The problem is the accurate assessment of adhesion in the carbon fiber–polymer matrix system since it affects the [...] Read more.
Carbon-fiber-reinforced plastics are composite materials with record-high specific strength, which depends on the efficiency of stress redistribution between the reinforcing fibers by the polymer matrix. The problem is the accurate assessment of adhesion in the carbon fiber–polymer matrix system since it affects the overall strength of the composite. This paper provides a novel electrochemical method for determining adhesion by estimating the critical length of carbon fibers that protrude above the fracture surface of the fiber-reinforced composite using their electrical conductivity and insulating properties of the polymer matrix. The method has been successfully applied to evaluate adhesion in carbon plastics having an epoxy matrix filled with nanoparticles of different anisometry: carbon nanotubes, organomodified montmorillonite, or detonation nanodiamonds. In addition to adhesion measurements, the effect of nanoparticles on the viscosity of epoxy binder, its impregnation efficiency of carbon fibers, curing, glass transition, and tensile strength of fiber-reinforced composites was estimated. Nanodiamonds at a mass fraction of 0.1% proved to be the most effective for improving the quality of epoxy carbon plastics, increasing fiber–matrix adhesion by 2.5 times, tensile strength by 17%, and not decreasing the glass transition temperature. Full article
(This article belongs to the Special Issue Advanced Polymeric Composites and Hybrid Materials)
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15 pages, 4586 KiB  
Article
Static and Fatigue Tensile Properties of Cross-Ply Carbon-Fiber-Reinforced Epoxy-Matrix-Composite Laminates with Thin Plies
by Kimiyoshi Naito, Yuto Seki and Ryo Inoue
J. Compos. Sci. 2023, 7(4), 146; https://doi.org/10.3390/jcs7040146 - 06 Apr 2023
Cited by 3 | Viewed by 1878
Abstract
Carbon-fiber-reinforced epoxy-matrix composite (CFRP) laminates with thin plies have strong damage-resistance properties compared with standard prepregs. The static and fatigue tensile fracture behavior of cross-ply CFRP laminates with thin plies should be further studied to establish the applicability of thin-ply prepregs for industrial [...] Read more.
Carbon-fiber-reinforced epoxy-matrix composite (CFRP) laminates with thin plies have strong damage-resistance properties compared with standard prepregs. The static and fatigue tensile fracture behavior of cross-ply CFRP laminates with thin plies should be further studied to establish the applicability of thin-ply prepregs for industrial structures. In this study, the static and fatigue tensile properties of cross-ply, high-strength polyacrylonitrile (PAN)-based carbon-fiber (T800SC)-reinforced epoxy-matrix composites with thin plies were investigated. The fiber orientations of the CFRP specimens were set to cross-ply with [0/90]10S (subscript S means symmetry), [(0)5/(90)5]2S, and [(0)10/(90)10]S. The static and fatigue tensile characteristics of the cross-ply CFRPs with thick plies with [0/90]2S and [(0)2/(90)2]S were also investigated for comparison. Under static loading, the tensile strength and failure strain of the thinnest 90°-ply-CFRP specimens were more than 5% higher than those of the other 90°-ply-thickness specimens. However, the tensile moduli and Poisson’s ratios were comparable between the cross-ply CFRPs with thin and thick plies. Under fatigue loading, the fatigue responses of the thinnest 90°-ply-CFRP specimens were 3% higher than those of the other 90°-ply-thickness specimens during lower-fatigue-cycle testing (<105 cycles). However, during higher-fatigue-cycle testing (>105 cycles), the fatigue responses decreased, with a decrease in the 90°-ply thickness, and the fatigue characteristics of the thinnest 90°-ply-CFRP specimen were 7% lower than those of the other cross-ply thin- and thick-ply-CFRP specimens. Full article
(This article belongs to the Topic Advanced Carbon Fiber Reinforced Composite Materials)
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11 pages, 1837 KiB  
Article
Numerical Construction of the Homogenized Strength Criterion for Fiber-Reinforced Composite
by Alexander G. Kolpakov and Sergei I. Rakin
J. Compos. Sci. 2023, 7(4), 145; https://doi.org/10.3390/jcs7040145 - 06 Apr 2023
Viewed by 971
Abstract
In this paper, we investigate whether the strength characteristics of composite materials can be described through the predictions of the homogenization theory concerning local stresses. We establish the homogenized strength criterion (HSC) of composite materials, following the general scheme developed in the homogenization [...] Read more.
In this paper, we investigate whether the strength characteristics of composite materials can be described through the predictions of the homogenization theory concerning local stresses. We establish the homogenized strength criterion (HSC) of composite materials, following the general scheme developed in the homogenization theory. Since the homogenization theory involves solving the so-called periodicity cell problem (PCP), HSC can be constructed in the form of a computer procedure only. We developed the HSC computer program and carried out numerical calculations for fiber-reinforced material. We conclude that HSC can be used to calculate safety zones and the first failure strength criteria (see detailed definitions below). We present numerically calculated safety zones and fracture surfaces for several cases. Full article
(This article belongs to the Section Fiber Composites)
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