Polymers

13 pages, 8313 KiB

Open AccessArticle

Influence of Modified PVA Fiber on Ultra-High Performance Concrete and Its Enhancing Mechanism

by Zhiyuan Chen, Hongyu Fan, Wanying Zheng, Siheng Zhang, Xi Wu, Tengfei Fu and Demei Yu

Polymers 2024, 16(23), 3449; https://doi.org/10.3390/polym16233449 - 9 Dec 2024

Viewed by 799

In this study, the properties of ultra-high-performance concrete (UHPC) were enhanced by adding modified polyvinyl alcohol (PVA) fibers. The specimens with different curing ages were evaluated in various aspects to investigate the effects of different dosages, lengths, and surface treatments of PVA fibers [...] Read more.

In this study, the properties of ultra-high-performance concrete (UHPC) were enhanced by adding modified polyvinyl alcohol (PVA) fibers. The specimens with different curing ages were evaluated in various aspects to investigate the effects of different dosages, lengths, and surface treatments of PVA fibers on the performance of UHPC. The performance was compared with that of steel fiber-reinforced UHPC with the same ratio and multiple dosages. At the same time, the distribution of fibers and the morphology of fibers were observed by a scanning electron microscope, and the mechanism of fiber reinforcement was discussed. The results showed that the mechanical properties were significantly affected by the fiber dosage, length, and surface treatment. Based on the test results, the optimum PVA fiber addition can increase the compressive strength and flexural strength by 12.0% and 6.0% compared to the control UHPC without fibers. A comprehensive evaluation was carried out and indicated that the optimum PVA fiber addition has the potential to replace 0.5% steel fiber in certain conditions. Full article

(This article belongs to the Special Issue High-Performance Fiber-Reinforced Polymer Composites)

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12 pages, 2894 KiB

Open AccessArticle

Efficient Prediction of Fatigue Damage Analysis of Carbon Fiber Composites Using Multi-Timescale Analysis and Machine Learning

by Satoru Yoshimori, Jun Koyanagi and Ryosuke Matsuzaki

Polymers 2024, 16(23), 3448; https://doi.org/10.3390/polym16233448 - 9 Dec 2024

Viewed by 724

Abstract

Carbon fiber reinforced plastic (CFRP) possesses numerous advantages, such as a light weight and high strength; however, its complex damage mechanisms make the evaluation of fatigue damage particularly challenging. Therefore, this study proposed and demonstrated an entropy-based damage evaluation model for CFRP that [...] Read more.

Carbon fiber reinforced plastic (CFRP) possesses numerous advantages, such as a light weight and high strength; however, its complex damage mechanisms make the evaluation of fatigue damage particularly challenging. Therefore, this study proposed and demonstrated an entropy-based damage evaluation model for CFRP that leverages the entropy derived from heat capacity measurements and does not require knowledge of the loading history. This entropy-based fatigue degradation model, though accurate, is computationally intensive and impractical for high-cycle analysis. To address this, we reduce computational cost through multi-timescale analysis, replacing cyclic loading with constant displacement loading. Characteristic variables are optimized using the machine learning model LightGBM and the response surface method (RSM), with LightGBM achieving a 75% lower root mean squared error than RSM by increasing features from 3 to 21. This approach cuts analysis time by over 90% while retaining predictive accuracy, showing that LightGBM outperforms RSM and that multi-timescale analysis effectively reduces computational demands. Full article

(This article belongs to the Special Issue Mechanical and Dynamic Characteristics of Polymers and Polymer Composites)

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12 pages, 5788 KiB

Open AccessArticle

Effects of Sizing Agents and Resin-Formulated Matrices with Varying Stiffness–Toughness Ratios on the Properties of Carbon Fiber Epoxy Resin Composites

by Pengfei Song, Qianli Fang, Wen Liu, Xinyue Ma, Qingchao Li, Mehraj-ud-din Naik, Mudasir Ahmad, Guoqing Huang and Chuncai Yang

Polymers 2024, 16(23), 3447; https://doi.org/10.3390/polym16233447 - 9 Dec 2024

Cited by 1 | Viewed by 714

Abstract

Interlaminar shear strength (ILSS) and compressive strength are two of the most critical properties of carbon fiber-reinforced polymer (CFRP). In this report, three types of epoxy resins—4,4’-diaminodiphenylmethane epoxy resin (AG-80), bisphenol A epoxy resin (E-1NT), and novolac epoxy (EPN)—were studied. E-1NT is characterized [...] Read more.

Interlaminar shear strength (ILSS) and compressive strength are two of the most critical properties of carbon fiber-reinforced polymer (CFRP). In this report, three types of epoxy resins—4,4’-diaminodiphenylmethane epoxy resin (AG-80), bisphenol A epoxy resin (E-1NT), and novolac epoxy (EPN)—were studied. E-1NT is characterized by low viscosity and low cost but exhibits poor mechanical properties, while AG-80 offers better wetting with carbon fiber. These two epoxy resins were mixed in various mass ratios. The study revealed that as the AG-80 content increased, the ILSS of the composite also increased, reaching a maximum of 94.04 MPa when the AG-80 content reached 60%. Beyond this point, further increases in AG-80 did not enhance the ILSS. Conversely, the compressive strength initially increased but then declined sharply as the AG-80 ratio increased. The maximum compressive strength was recorded at 748.52 MPa when the AG-80 content reached 60%, which was 21% higher than pure AG-80 and 32% higher than pure E-1NT. Additionally, the study examined three different types of ionic sizing agents and four different resin matrices (E-1NT/DDS, AG-80/DDS, AG-80/E-1NT/DDS, EPN/DDS). Among them, the 60% AG-80/40% E-1NT/DDS/CF formulation demonstrated the best balance in both ILSS and compressive strength. Full article

(This article belongs to the Section Polymer Analysis and Characterization)

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14 pages, 3383 KiB

Open AccessArticle

Friction Behaviors and Wear Mechanisms of Carbon Fiber Reinforced Composites for Bridge Cable

by Guijun Xian, Xiao Qi, Rui Guo, Jingwei Tian, Huigang Xiao and Chenggao Li

Polymers 2024, 16(23), 3446; https://doi.org/10.3390/polym16233446 - 9 Dec 2024

Viewed by 840

Abstract

Carbon fiber reinforced epoxy resin composites (CFRP) demonstrate superior wear resistance and fatigue durability, which are anticipated to markedly enhance the service life of structures under complex conditions. In the present paper, the friction behaviors and wear mechanisms of CFRP under different applied [...] Read more.

Carbon fiber reinforced epoxy resin composites (CFRP) demonstrate superior wear resistance and fatigue durability, which are anticipated to markedly enhance the service life of structures under complex conditions. In the present paper, the friction behaviors and wear mechanisms of CFRP under different applied loads, sliding speeds, service temperatures, and water lubrication were studied and analyzed in detail. The results indicated that the tribological properties of CFRP were predominantly influenced by the applied loads, as the tangential displacement generated significant shear stress at the interface of the friction pair. Serviced temperature was the next most impactful factor, while the influence of water lubrication remained minimal. Moreover, when subjected to a load of 2000 g, the wear rate and scratch width of the samples exhibited increases of 158% and 113%, respectively, compared to those loaded with 500 g. This observed escalation in wear characteristics can be attributed to irreversible debonding damage at the fiber/resin interface, leading to severe delamination wear. At elevated temperatures of 100 °C and 120 °C, the wear rate of CFRP increased by 75% and 112% compared to that at room temperature. This augmentation in wear was attributed to the transition of the epoxy resin from a glassy to an elastic state, which facilitated enhanced fatigue wear. Furthermore, both sliding speed and water lubrication displayed a negligible influence on the friction coefficient of CFRP, particularly under water lubrication conditions at 60 °C, where the friction coefficient was only 15%. This was because the lubricant properties and thermal management provided by the water molecules, which mitigated the frictional interactions, led to only minor abrasive wear. In contrast, the wear rate of CFRP at a sliding speed of 120 mm/s was found to be 74% greater than that observed at 60 mm/s. This significant increase can be attributed to the disparity in sliding rates, which induced uncoordinated deformation in the surface and subsurface of the CFRP, resulting in adhesive wear. Full article

(This article belongs to the Section Polymer Processing and Engineering)

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2 pages, 512 KiB

Open AccessCorrection

Correction: Habib et al. Thiolated Chitosan Microneedle Patch of Levosulpiride from Fabrication, Characterization to Bioavailability Enhancement Approach. Polymers 2022, 14, 415

by Rukhshanda Habib, Abul Kalam Azad, Muhammad Akhlaq, Fakhria A. Al-Joufi, Gul Shahnaz, Hanan R. H. Mohamed, Muhammad Naeem, Abdulraheem S. A. Almalki, Junaid Asghar, Aamir Jalil and Mohamed M. Abdel-Daim

Polymers 2024, 16(23), 3445; https://doi.org/10.3390/polym16233445 - 9 Dec 2024

Viewed by 897

Abstract

In the original publication [...] Full article

23 pages, 3215 KiB

Open AccessArticle

Alfalfa/Lucerne (Medicago sativa) as a Source of Functional Bioadditives for Elastomeric Natural Rubber Composites

by Justyna Miedzianowska-Masłowska, Marcin Masłowski and Krzysztof Strzelec

Polymers 2024, 16(23), 3444; https://doi.org/10.3390/polym16233444 - 9 Dec 2024

Viewed by 695

Abstract

This study explores the impact of three bioadditives derived from Alfalfa—biomass, bio-ashes, and lyophilisates—on natural rubber composites, with a primary focus on the anti-aging properties of lyophilisates. Composite samples were prepared by incorporating these bioadditives into natural rubber and analyzed using various characterization [...] Read more.

This study explores the impact of three bioadditives derived from Alfalfa—biomass, bio-ashes, and lyophilisates—on natural rubber composites, with a primary focus on the anti-aging properties of lyophilisates. Composite samples were prepared by incorporating these bioadditives into natural rubber and analyzed using various characterization techniques to evaluate mechanical, thermal, aging, and surface properties. The results highlight the promising anti-aging effects of lyophilisates, significantly enhancing the aging resistance of natural rubber. The aging factor was the closest to unity among all systems. Biomass and bio-ashes were also examined, offering insights into their influence on tensile strength, viscoelasticity, and surface wettability. The tensile strength values were almost 50% higher than those of the reference sample (8.5 MPa). The study provides a detailed understanding of the interactions between these bioadditives and natural rubber, showcasing their potential to enhance elastomer performance. These findings underscore the viability of Alfalfa-based bioadditives as sustainable options for improving rubber properties, with significant implications for industrial applications. Full article

(This article belongs to the Special Issue Advances in Natural Fiber-Polymer Composites)

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Graphical abstract

19 pages, 6853 KiB

Open AccessArticle

The Finite Element Method in Thermosetting Polymers’ and FRPs’ Supramolecular Structure and Thermomechanical Properties’ Modeling

by Alexander Korolev, Alexander Zadorin and Maxim Mishnev

Polymers 2024, 16(23), 3443; https://doi.org/10.3390/polym16233443 - 8 Dec 2024

Viewed by 858

Abstract

The object of research is cured thermosetting epoxy polymer and FRP on the base of the same polymer matrix. The purpose of this research is to develop the finite element (FE) method in the modeling of cured thermosetting polymers and FRPs to predict [...] Read more.

The object of research is cured thermosetting epoxy polymer and FRP on the base of the same polymer matrix. The purpose of this research is to develop the finite element (FE) method in the modeling of cured thermosetting polymers and FRPs to predict their mechanical and thermal properties. The structural mathematical modeling with subsequent computer FE modeling was performed. The results of FE modeling were compared with the experimental data of cured polymer’s and FRP’s tensile strength and deformations under mechanical load at different temperatures. The design of the polymer’s FE model was based on the tetrahedral supramolecular structure and then transformed into FRP’s model by integrating glass fiber rods. Using the structural density as the structure model’s parameter, the relative size and disposition of the finite elements were determined. The viscoelastic properties are set in the model by regulating the structural density and compressive/tensile properties of joints. The long-term plastic deformation and stress relaxation were determined as the result of the supramolecular structure’s inner shearing with the decrease of its structural density. The FE models of the cured epoxy polymer and FRP were developed, making it possible to predict short-term and long-term deformations under load with high accuracy considering the temperature factor. Full article

(This article belongs to the Special Issue Computational and Experimental Approaches in Polymeric Materials)

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21 pages, 6126 KiB

Open AccessArticle

Influence of Lignin Type on the Properties of Hemp Fiber-Reinforced Polypropylene Composites

by Florin Ciolacu, Teodor Măluțan, Gabriela Lisa and Mariana Ichim

Polymers 2024, 16(23), 3442; https://doi.org/10.3390/polym16233442 - 8 Dec 2024

Viewed by 906

Abstract

Increasing environmental awareness has boosted interest in sustainable alternatives for binding natural reinforcing fibers in composites. Utilizing lignin, a biorenewable polymer byproduct from several industries, as a component in polymer matrices can lead to the development of more eco-friendly and high-performance composite materials. [...] Read more.

Increasing environmental awareness has boosted interest in sustainable alternatives for binding natural reinforcing fibers in composites. Utilizing lignin, a biorenewable polymer byproduct from several industries, as a component in polymer matrices can lead to the development of more eco-friendly and high-performance composite materials. This research work aimed to investigate the effect of two types of lignin (lignosulfonate and soda lignin) on the properties of hemp fiber-reinforced polypropylene composites for furniture applications. The composites were produced by thermoforming six overlapping layers of nonwoven material. A 20% addition of soda lignin or lignosulfonate (relative to the nonwoven mass) was incorporated between the nonwoven layers made of 80% hemp and 20% polypropylene (PP). The addition of both types of lignin resulted in an increase in the tensile and bending strength of lignin-based composites, as well as a decrease in the absorbed water percentage. Compared to oriented strand board (OSB), lignin-based composites exhibited better properties. Regarding the two types of lignin used, the addition of lignosulfonate resulted in better composite properties than those containing soda lignin. Thermal analysis revealed that the thermal degradation of soda lignin begins long before the melting temperature of polypropylene. This early degradation explains the inferior properties of the composites containing soda lignin compared to those with lignosulfonate. Full article

(This article belongs to the Special Issue Fiber-Reinforced Polymer Composites: Progress and Prospects)

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15 pages, 20460 KiB

Open AccessArticle

Compatibilizer Efficiency in Enhancing Marine Plastic Waste Valorization Through Simulated Recycled Plastic Blends

by Sibele Piedade Cestari, Pedro Veiga Rodrigues, Ana Cristina Ribeiro, Maria Cidália Rodrigues Castro, Vasco Cruz, Ana Rita Torres, Nuno Ramos and Ana Vera Machado

Polymers 2024, 16(23), 3441; https://doi.org/10.3390/polym16233441 - 8 Dec 2024

Viewed by 830

Abstract

This study investigated the optimal combination of compatibilizers and stabilizers to enhance the value of marine environment plastic (MEP). The composition of the plastics was analysed, and a simulated recycled plastic blend (sMEP) was prepared based on a simplified composition of actual MEP. [...] Read more.

This study investigated the optimal combination of compatibilizers and stabilizers to enhance the value of marine environment plastic (MEP). The composition of the plastics was analysed, and a simulated recycled plastic blend (sMEP) was prepared based on a simplified composition of actual MEP. Different concentrations of three commercial compatibilizers (C1, C2 and C3) were tested to improve tensile strength. The tensile tests indicated that the blend compatibilized with 10 wt.% C3 (polypropylene grafted with maleic anhydride) exhibited the highest increase in tensile strength. This optimal compatibilization was then combined with two commercial stabilizers and applied to a simulated MEP blend. Scanning electron microscopy images showed that all blends had a continuous polyethylene phase with dispersed poly(ethylene terephthalate) (PET) and polypropylene (PP) droplets. The simulated blend with 10 wt.% C3 exhibited a reduced PET droplet size in the dispersed phase. Differential scanning calorimetry results revealed a decrease in polyethylene crystallinity and an increase in PP crystallinity. The improved properties of the blend were attributed to the effectiveness of the C3 compatibilizer in enhancing the interface between the PP and PET phases. An effective formulation was developed to valorise marine-sourced plastics by leveraging existing scientific knowledge and accessible commercial additives. Applying this enhanced formulation to real MEP not only demonstrated its effectiveness, but also highlighted a practical approach for reducing plastic pollution and supporting circular economy principles, contributing to environmental conservation efforts. Full article

(This article belongs to the Special Issue Innovations in Polymer Composites for Sustainable Energy Harvesting and Environmental Applications)

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5 pages, 195 KiB

Open AccessEditorial

Advances in Multifunctional Polymer-Based Nanocomposites

by Jia-Wun Li, Chih-Chia Cheng and Chih-Wei Chiu

Polymers 2024, 16(23), 3440; https://doi.org/10.3390/polym16233440 - 8 Dec 2024

Viewed by 1243

Abstract

“Advances in Multifunctional Polymer-Based Nanocomposites” presents the results of pioneering research in a new direction in the field of materials science and engineering technology [...] Full article

(This article belongs to the Special Issue Advances in Multifunctional Polymer-Based Nanocomposites)

20 pages, 10642 KiB

Open AccessArticle

A UV-Protective Textile Coating Based on Recycled Poly(vinyl butyral) (PVB): A New Life for a Waste Polymer

by Noemi Cei, Ilaria Canesi, Stefano Nejrotti, Giorgia Montalbano, Hamideh Darjazi, Alessandro Piovano, Matteo Bonomo, Alberto Fina, Beatriz Yecora, Angelica Perez, Claudia Barolo, Claudio Gerbaldi and Daniele Spinelli

Polymers 2024, 16(23), 3439; https://doi.org/10.3390/polym16233439 - 7 Dec 2024

Viewed by 1154

Abstract

Polyvinyl butyral (PVB) is a high-performance thermoplastic polymer, commonly used as an interlayer material in laminated safety glass for the automotive and architectural sectors. Currently, there is no end-of-life cycle program for a substantial amount of PVB film, which mainly ends up in [...] Read more.

Polyvinyl butyral (PVB) is a high-performance thermoplastic polymer, commonly used as an interlayer material in laminated safety glass for the automotive and architectural sectors. Currently, there is no end-of-life cycle program for a substantial amount of PVB film, which mainly ends up in landfills. According to a circular approach, PVB can be revalorized after efficient separation and recovery from glass. Thus, the aim of this work was to develop functional coatings for textile applications using recycled PVB (re-PVB), also in combination with an organic UV absorber, to enable the production of UV-protective final coated fabrics. The re-PVB-coated fabrics were obtained through an industrially scalable spraying process (leading to an average weight increase of 20 ± 3 wt.%), and the effectiveness of the application was evaluated according to different characterization techniques, such as FT-IR (Fourier transform–infrared) spectroscopy, SEM (scanning electron microscope), a washing test, a mechanical test, a thermo-physiological test, and the ultraviolet protection factor (UPF). Based on the results, the re-PVB-coated fabrics appeared stable upon washing (with a negligible weight loss compared to the average amount of coating) and effective in UV protection (with a final UPF being four times higher and a reduced UVA transmittance from 2.0% to 0.6%). Full article

(This article belongs to the Collection Progress in Polymer Applications)

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22 pages, 855 KiB

Open AccessPerspective

Is Kraft Pulping the Future of Biorefineries? A Perspective on the Sustainability of Lignocellulosic Product Development

by Kalavathy Rajan, Paula Berton, Robin D. Rogers and Julia L. Shamshina

Polymers 2024, 16(23), 3438; https://doi.org/10.3390/polym16233438 - 7 Dec 2024

Cited by 1 | Viewed by 1072

Abstract

By reflecting on the history and environmental impact of conventional biorefining, such as kraft pulping, we aim to explore important questions about how natural polymers can be more sustainably sourced to develop bio-products and reduce reliance on plastics. Since the Industrial Revolution, chemical [...] Read more.

By reflecting on the history and environmental impact of conventional biorefining, such as kraft pulping, we aim to explore important questions about how natural polymers can be more sustainably sourced to develop bio-products and reduce reliance on plastics. Since the Industrial Revolution, chemical pulping processes have enabled the mass production of cellulosic products from woody biomass. Kraft pulping, which dominates within modern pulp and paper mills, has significantly contributed to environmental pollution and carbon emissions due to sulfurous byproducts and its high water and energy consumption. While chemical pulping technologies have advanced over time, with improvements aimed at enhancing sustainability and economic feasibility, conventional biorefineries still face challenges related to biomass conversion efficiency and environmental impact. For example, efforts to fully utilize wood resources, such as isolating lignin from black liquor, have made limited progress. This perspective provides a thoughtful examination of the growth of chemical pulping, particularly the kraft process, in the production of consumer goods and its environmental consequences. It also presents key insights into the bottlenecks in developing truly sustainable biomass conversion technologies and explores potential alternatives to traditional chemical pulping. Full article

(This article belongs to the Special Issue Polysaccharide and Lignocellulose Materials)

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14 pages, 3148 KiB

Open AccessArticle

Preparation and Performance Analysis of Tung Cake Protein Adhesive

by Wei Wang, Ke Zheng, Wenzheng Zhao, Shenglong Zheng, Hui Wan and Jingran Gao

Polymers 2024, 16(23), 3437; https://doi.org/10.3390/polym16233437 - 7 Dec 2024

Viewed by 712

Abstract

Tung oil pressing generates a substantial amount of tung cake waste rich in protein, which can be used to develop a novel wood protein adhesive. This study determined the optimal alkali treatment parameters based on NaOH concentration, reaction temperature, and reaction time. Potassium [...] Read more.

Tung oil pressing generates a substantial amount of tung cake waste rich in protein, which can be used to develop a novel wood protein adhesive. This study determined the optimal alkali treatment parameters based on NaOH concentration, reaction temperature, and reaction time. Potassium permanganate (KMnO₄) and methyl trimethoxy silane (MTMS) were then sequentially added for cross-linking modification to achieve the optimal preparation process for the tung cake protein adhesive. Bonding strength was tested on pressed boards, and various characterization techniques, including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Thermogravimetric analysis (TG/TGA), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM), were used. The results indicated the following: (1) Optimal preparation conditions: The best preparation process for the adhesive involved 30% NaOH at 50 °C for 50 min, with the addition of 12% KMnO₄ and 6% MTMS, meeting Class II plywood standards. (2) XRD and FTIR analyses revealed that carbohydrates in the tung cake oxidized and reacted with protein amino groups. The active groups in the protein cross-linked with MTMS, forming a spatial network structure, reducing hydrophilic groups, and enhancing water resistance. (3) TG/TGA and DSC showed that the thermal stability of the modified adhesive improved, thermogravimetric loss was reduced, and curing performance was enhanced. (4) SEM verified the adhesive’s reaction mechanism, demonstrating that MTMS filled the protein structure unfolded by KMnO₄, forming a three-dimensional network and improving bonding strength. This study successfully developed a new, formaldehyde-free, environmentally friendly tung cake protein adhesive with excellent performance. Full article

(This article belongs to the Section Polymer Analysis and Characterization)

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17 pages, 7695 KiB

Open AccessArticle

Experimental and Numerical Study on the Impact Response of Composite Sandwich Structures with Different Cores

by Guangshuo Feng, Chunlu Xiao, Bo Liu, Haitao Zhang, Peipei Jia and Caizheng Wang

Polymers 2024, 16(23), 3436; https://doi.org/10.3390/polym16233436 - 7 Dec 2024

Viewed by 842

Abstract

This study analyzes the impact mechanical response of sandwich structures with foam and wood cores through experimental and numerical methods. The aim is to determine whether a sustainable core material, such as cork wood, can serve as a reliable alternative to the commonly [...] Read more.

This study analyzes the impact mechanical response of sandwich structures with foam and wood cores through experimental and numerical methods. The aim is to determine whether a sustainable core material, such as cork wood, can serve as a reliable alternative to the commonly used Polystyrene (PS) foam core in sandwich structures. Impact experiments were conducted at varying energy levels using an INSTRON CEAST 9350 drop tower, demonstrating the superiority of sandwich structures compared to single-material alternatives. Numerical models were developed in ABAQUS, where glass fiber reinforced polymer (GFRP) composite panels were represented using solid element C3D8R and the 3D Hashin failure criteria, which were incorporated via the user subroutine VUMAT. The results indicate that the contact force of the sandwich structure with a wood core surpassed that of the foam core counterpart. In both sandwich structures, damage initially occurred at the impact point on the surface, leading to plastic deformation and damage within the core, while the composite panel on the rear surface ultimately failed. These findings provide valuable insights for designers, enabling parametric studies to select appropriate core materials that enhance the impact resistance of sandwich structures. Full article

(This article belongs to the Section Polymer Composites and Nanocomposites)

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15 pages, 3182 KiB

Open AccessArticle

Optimization of Compression Molding Parameters and Lifecycle Carbon Impact Assessment of Bamboo Fiber-Reinforced Polypropylene Composites

by Wei Li, Tao Feng, Tongyuan Lu, Feng Zhao, Jialong Zhao, Wei Guo and Lin Hua

Polymers 2024, 16(23), 3435; https://doi.org/10.3390/polym16233435 - 6 Dec 2024

Viewed by 932

Abstract

Driven by global carbon neutrality goals, bamboo fiber-reinforced PP composites have shown significant potential for automotive applications due to their renewability, low carbon emissions, and superior mechanical properties. However, the environmental complexities associated with compression molding process parameters, which impact material properties and [...] Read more.

Driven by global carbon neutrality goals, bamboo fiber-reinforced PP composites have shown significant potential for automotive applications due to their renewability, low carbon emissions, and superior mechanical properties. However, the environmental complexities associated with compression molding process parameters, which impact material properties and carbon emissions, pose challenges for large-scale adoption. This study systematically optimized the compression molding process of bamboo fiber-reinforced PP composites through a three-factor, five-level experimental design, focusing on preheating temperature, preheating time, and holding time. Additionally, an innovative life cycle assessment (LCA) was conducted to evaluate the environmental impact. The results indicated that at a preheating temperature of 220 °C, preheating time of 210–240 s, and holding time of 40–50 s, the material achieved a tensile strength of 35 MPa and a flexural strength of 45 MPa, with a 15% reduction in water absorption. The LCA further highlighted energy consumption, the compression molding process, and material composition as the primary contributors to carbon emissions and environmental impacts, identifying key areas for future optimization. This study provides an optimized framework for compression molding bamboo fiber-reinforced PP composites and establishes a theoretical foundation for their low-carbon application in the automotive industry. Future work will explore the optimization of bamboo fiber content and process parameters to further enhance material performance and reduce environmental impact. Full article

(This article belongs to the Special Issue Fiber and Polymer Composites: Processing, Simulation, Properties and Applications, 3rd Edition)

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19 pages, 939 KiB

Open AccessReview

Does the Incorporation of Biochar into Biodegradable Mulch Films Provide Agricultural Soil Benefits?

by Kesinee Iamsaard, Nuttapon Khongdee, Raweerat Rukkhun, Charoon Sarin, Pantip Klomjek and Chanin Umponstira

Polymers 2024, 16(23), 3434; https://doi.org/10.3390/polym16233434 - 6 Dec 2024

Cited by 1 | Viewed by 1026

Abstract

The pollution caused by plastic mulch film in agriculture has garnered significant attention. To safeguard the ecosystem from the detrimental effects of plastic pollution, it is imperative to investigate the use of biodegradable materials for manufacturing agricultural plastic film. Biochar has emerged as [...] Read more.

The pollution caused by plastic mulch film in agriculture has garnered significant attention. To safeguard the ecosystem from the detrimental effects of plastic pollution, it is imperative to investigate the use of biodegradable materials for manufacturing agricultural plastic film. Biochar has emerged as a feasible substance for the production of biodegradable mulch film (BDM), providing significant agricultural soil benefits. Although biochar has been widely applied in BDM manufacturing, the effect of biochar-filled plastic mulch film on soil carbon stock after its degradation has not been well documented. This study provides an overview of the current stage of biochar incorporated with BDM and summarizes its possible pathway on soil carbon stock contribution. The application of biochar-incorporated BDM can lead to substantial changes in soil microbial diversity, thereby influencing the emissions of greenhouse gases. These alterations may ultimately yield unforeseen repercussions on the carbon cycles. However, in light of the current knowledge vacuum and potential challenges, additional study is necessary to ascertain if biochar-incorporated BDM can effectively mitigate the issues of residual mulch film and microplastic contamination in agricultural land. Significant progress remains necessary before BDM may fully supplant traditional agricultural mulch film in agricultural production. Full article

(This article belongs to the Special Issue Advanced Biopolymers and Biocomposites)

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23 pages, 6353 KiB

Open AccessArticle

Effects of Hygrothermal Condition on Water Diffusion and Flexural Properties of Carbon–Glass Hybrid Fiber-Reinforced Epoxy Polymer Winding Pipes

by Ying Zhao, Qiang Li, Guoqiang Zhou, Kehai Zhu, Bo Jing, Kangnan Zhu, Jiajun Shi and Chenggao Li

Polymers 2024, 16(23), 3433; https://doi.org/10.3390/polym16233433 - 6 Dec 2024

Viewed by 654

Abstract

Carbon–glass hybrid fiber-reinforced epoxy polymer (C-GFRP) winding pipes integrated with the advantages of light weight, high strength, corrosion resistance, and cost-effectiveness offer immense potential to mitigate corrosion issues in oil, gas, and water transportation pipelines. In this study, C-GFRP winding pipes underwent accelerated [...] Read more.

Carbon–glass hybrid fiber-reinforced epoxy polymer (C-GFRP) winding pipes integrated with the advantages of light weight, high strength, corrosion resistance, and cost-effectiveness offer immense potential to mitigate corrosion issues in oil, gas, and water transportation pipelines. In this study, C-GFRP winding pipes underwent accelerated aging tests through immersion in distilled water at temperatures of 25 °C, 40 °C, and 60 °C for 146 days. Water absorption tests were conducted to investigate the water absorption behavior of only CFRP- or GFRP-side absorbed water. Bending tests were performed to assess the evolution of the pipes’ flexural properties in two directions (GFRP or CFRP in tension). The results showed that the single-sided water absorption behavior adhered to the two-stage diffusion model. The diffusion coefficient, activation energy, and 146-day water absorption were all higher for the CFRP-side absorbed water compared to the GFRP-side absorbed water. The flexural strength and modulus of C-GFRP pipes were influenced by post-curing and resin hydrolysis/debonding. Initially, the flexural strength of CFRP in tension was higher than that of CFRP in tension. After 146 days of aging, the flexural strength of CFRP in tension was lower than that of CFRP in tension. Utilizing Arrhenius theory, the long-term lives were predicted for the flexural strength at temperatures of 5.4 °C, 12.8 °C, and 17.8 °C. The predicted lives of GFRP in tension were higher than those of CFRP in tension. Full article

(This article belongs to the Section Polymer Applications)

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17 pages, 3568 KiB

Open AccessArticle

Recycling of Bovine Hair Waste Through the Design of a Compatibilizing Agent for Sustainable Thermoplastic Starch-Untreated Bovine Hair Composites

by Luz Elena Mora-Maldonado, Anayansi Estrada-Monje, Roberto Zitzumbo-Guzmán, Isis Rodríguez-Sánchez, Leonardo Baldenegro-Pérez, Claudia Ivone Piñón-Balderrama, Saddys Rodríguez-Llamazares and Erasto Armando Zaragoza-Contreras

Polymers 2024, 16(23), 3432; https://doi.org/10.3390/polym16233432 - 6 Dec 2024

Viewed by 584

Abstract

Bovine hair waste was chemically modified to obtain a coupling agent (CA) for the compatibilization of thermoplastic starch (TPS)-unmodified bovine hair waste (UH) composites. The composites processed with CA presented improved tensile strength (3.5 MPa) compared to TPS–UH composites without CA (1.25 MPa). [...] Read more.

Bovine hair waste was chemically modified to obtain a coupling agent (CA) for the compatibilization of thermoplastic starch (TPS)-unmodified bovine hair waste (UH) composites. The composites processed with CA presented improved tensile strength (3.5 MPa) compared to TPS–UH composites without CA (1.25 MPa). An interaction mechanism to describe the improvement in mechanical properties and thermal stability was postulated based on Fourier-transform infrared spectroscopy (FTIR) and density functional theory (DFT). In addition, optical and electron microscopy showed that CA favored the adhesion of UH to TPS. Global results suggested the formation of a CA–UH network that interacts with the TPS matrix. Obtaining composites from waste from the tanning industry can contribute to the development of a more responsible and sustainable industry and represents an opportunity to reduce the environmental impact of one of the most important industries globally. It is worth mentioning that this research is aligned with the sustainable development goals (SDGs) proposed by the United Nations, which promotes sustainable industrialization and the promotion of innovation. Full article

(This article belongs to the Special Issue Advanced Study on Natural Polymers and Their Applications)

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18 pages, 5498 KiB

Open AccessReview

Surface Modification of Ultra-High-Molecular-Weight Polyethylene and Applications: A Review

by Jing He, Yuan Wang, Yong Qian, Jianshuang Guo, Jiaxin Lu and Weicheng Yang

Polymers 2024, 16(23), 3431; https://doi.org/10.3390/polym16233431 - 6 Dec 2024

Viewed by 1057

Abstract

Ultra-high-molecular-weight polyethylene (UHMWPE) is often considered an ideal reinforcing material due to its extraordinary characteristics like high abrasion resistance, excellent toughness, and chemical stability. However, the poor surface properties have significantly hindered the progress of UHMWPE with high performance. This review is intended [...] Read more.

Ultra-high-molecular-weight polyethylene (UHMWPE) is often considered an ideal reinforcing material due to its extraordinary characteristics like high abrasion resistance, excellent toughness, and chemical stability. However, the poor surface properties have significantly hindered the progress of UHMWPE with high performance. This review is intended to introduce the physicochemical mechanisms of UHMWPE interfacial property modification. Therefore, this review provides a concise overview of the progress in diverse surface modification techniques for UHMWPE and their strengths and limitations as polymer reinforcement materials. Lastly, an overview of the potential and challenges of each surface modification has been summarized. Full article

(This article belongs to the Section Polymer Chemistry)

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16 pages, 2876 KiB

Open AccessArticle

Effect of Bioactive Packaging Materials Based on Sodium Alginate and Protein Hydrolysates on the Quality and Safety of Refrigerated Chicken Meat

by Svetlana Merenkova and Oksana Zinina

Polymers 2024, 16(23), 3430; https://doi.org/10.3390/polym16233430 - 6 Dec 2024

Viewed by 695

Abstract

The purpose of this study was to evaluate the potential of alginate-based packaging materials with the incorporation of protein hydrolysates to improve the safety and quality of chicken meat during storage. Physicochemical parameters, microbiological indicators, and color characteristics of chicken meat packaged in [...] Read more.

The purpose of this study was to evaluate the potential of alginate-based packaging materials with the incorporation of protein hydrolysates to improve the safety and quality of chicken meat during storage. Physicochemical parameters, microbiological indicators, and color characteristics of chicken meat packaged in bioactive films were determined. We observed a significant increase in moisture content for samples in polyethylene films (by 10.5%) and decrease for the samples in alginate-based films by 5.3%. The highest mass losses were found for the sample without packaging material (20.4%) and for the samples wrapped in alginate films (15.9–17.9%). When packing meat samples by immersion method, a gradual decrease in weight was found (up to 9.1%). On the 7th day of storage, the pH value of the control sample reached 6.55, while for the samples in bioactive alginate-based materials pH level was 6.0–6.15. The most pronounced oxidative processes were observed in the control meat sample (5.1 mmol (

\frac{1}{2}

O₂)/kg). The application of bioactive alginate-based films led to a significant reduction in fatty peroxide value by 56.2%. The total microbial count in the meat samples packaged in bioactive films was 3.5–5 times lower than in the control sample. Chicken meat wrapped in alginate-based films with protein hydrolysates maintains more stable color characteristics, the lightness index (L) decreased to 37.5, and the redness index (b) increased to 3.4 on the 7th day of storage. Full article

(This article belongs to the Special Issue Natural-Based Biodegradable Polymeric Materials II)

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26 pages, 4129 KiB

Open AccessReview

Collagen-Based Scaffolds for Volumetric Muscle Loss Regeneration

by Anna L. Luss, Maria M. Bobrova, Pavel P. Kulikov and Anton A. Keskinov

Polymers 2024, 16(23), 3429; https://doi.org/10.3390/polym16233429 - 6 Dec 2024

Viewed by 998

Abstract

Volumetric muscle loss (VML) is a serious problem in healthcare that requires innovative solutions. Collagen and its derivatives are promising biomaterials for muscle tissue replacement due to their high biocompatibility, biodegradability, and lack of toxicity. This review comprehensively discusses collagen from various sources, [...] Read more.

Volumetric muscle loss (VML) is a serious problem in healthcare that requires innovative solutions. Collagen and its derivatives are promising biomaterials for muscle tissue replacement due to their high biocompatibility, biodegradability, and lack of toxicity. This review comprehensively discusses collagen from various sources, its structural characteristics, cross-linking methods to obtain hydrogels, and approaches to incorporating various therapeutic molecules to create a biocomposite system with controlled release. Collagen-based scaffolds are promising constructs in tissue engineering and regenerative medicine. They can both perform their function independently and act as a depot for various biologically active substances (drugs, growth factors, genetic material, etc.). Collagen-based scaffolds for muscle volume restoration are three-dimensional constructs that support cell adhesion and proliferation and provide controlled release of therapeutic molecules. Various mechanical and biological properties of scaffolds can be achieved by cross-linking agents and bioactive molecules incorporated into the structure. This review highlights recent studies on collagen-based hydrogels for restoration of volumetric muscle loss. Full article

(This article belongs to the Special Issue Polymer-Containing Nanomaterials: Synthesis, Properties, Applications)

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13 pages, 4415 KiB

Open AccessArticle

Vibration Behavior of 3D-Printed Graded Composites: Fabrication and Testing

by Fazeel Khan, Kumar Singh and Justin Carter

Polymers 2024, 16(23), 3428; https://doi.org/10.3390/polym16233428 - 6 Dec 2024

Viewed by 669

Abstract

Multi-head 3D printers afford the ability to create composite structures with significant differences in properties compared to those created through traditional molding techniques. In addition to the usage of different viscoelastic polymeric materials, the selective spatial placement of the build materials enables the [...] Read more.

Multi-head 3D printers afford the ability to create composite structures with significant differences in properties compared to those created through traditional molding techniques. In addition to the usage of different viscoelastic polymeric materials, the selective spatial placement of the build materials enables the creation of layered and graded geometries to achieve specific mechanical and/or vibrational characteristics. This paper describes how the mechanical properties of the individual materials can be used to predict the damping and natural frequencies of a 3D-printed graded structure. Such structures can find usage in rotating machinery, beams, etc., where vibrational characteristics must be controlled. The simulation and experimental results are presented and two forms of the storage and loss modulus are considered: fixed and variable. For the latter condition, E′ and E″ are established as functions of temperature and frequency. Modal vibration testing of the graded samples shows a good match between the simulation and experimental trials, thereby supporting the proposed model as a useful tool for prescribing the structure of a printed part with tailored dynamic properties. Full article

(This article belongs to the Special Issue 3D Printing of Polymer Composite Materials)

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30 pages, 10445 KiB

Open AccessArticle

Polymeric Infrared and Fluorescent Probes to Assess Macrophage Diversity in Bronchoalveolar Lavage Fluid of Asthma and Other Pulmonary Disease Patients

by Igor D. Zlotnikov and Elena V. Kudryashova

Polymers 2024, 16(23), 3427; https://doi.org/10.3390/polym16233427 - 5 Dec 2024

Cited by 1 | Viewed by 938

Abstract

Bronchial asthma remains a serious medical problem, as approximately 10% of patients fail to achieve adequate symptom control with available treatment options. Macrophages play a pivotal role in the pathophysiology of asthma, as well as in some other respiratory disorders. Typically, they are [...] Read more.

Bronchial asthma remains a serious medical problem, as approximately 10% of patients fail to achieve adequate symptom control with available treatment options. Macrophages play a pivotal role in the pathophysiology of asthma, as well as in some other respiratory disorders. Typically, they are classified into two major classes, M1 and M2; however, recent findings have indicated that in fact there is a whole range of macrophage polarization and functional diversity beyond this bimodal division. The isolation of individual cell sub-populations and the identification of their role and diagnostic/therapeutic significance is still a challenge. Here, we have attempted to assess the differences between patient-derived macrophage populations from bronchoalveolar lavage fluid (BALF) samples in different pulmonary disease conditions, based on their capability to interact with a range of specific and relatively non-specific carbohydrate-based ligands (containing galactose (linear or cyclic form), mannose, trimannose, etc.). Obviously, the main target of these ligands was CD206; however, other minor receptors, able to bind carbohydrates, have also been reported for macrophages. Trimannose binds most specifically to CD206 macrophage receptors, while monomannose has intermediate affinity, and galactose has low affinity and may involve binding to other receptors. This clearly indicates the ligands were chosen based on their predicted binding strength and specificity for CD206, providing the rationale for the study. In some cases, the activated macrophage affinity to galactose base ligands was higher than that to mannose, indicating that complexes of CD206 or other carbohydrate-binding receptors may contribute substantially to macrophage functional features. In addition, variations in receptor clustering and distribution may substantially affect affinity to the same ligand. Interestingly, with a panel of 6–10 different carbohydrate-based ligands with FTIR or fluorescent marker, we were able not only to distinguish between healthy and disease states but also between closely related diseases such as purulent endobronchitis, obstructive bronchitis, pneumonia, and bronchial asthma. For further investigation, specific sub-populations of macrophages, seen as hallmarks to specific diseases, can be isolated and studied separately, likely giving new insights with diagnostic and therapeutic significance for hard-to-treat patients. The group of patients with resistant disease can also be identified with this approach as a fingerprint method to find a more targeted therapeutic strategy, improving their clinical outcomes. As expected, this will provide a large additional array of data for analysis, compared to the work going on in the world. The dataset used by other researchers mainly for known “antibody” ligands is semi-quantitative and insufficient for the purposes of typing as yet unknown and uncomplicated sub-populations. The analysis of the presented data in combination with personalized information from patients’ medical records will be carried out using both traditional methods and machine learning methods. Full article

(This article belongs to the Special Issue Polymer Materials for Drug Delivery and Tissue Engineering II)

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12 pages, 4539 KiB

Open AccessArticle

A Flexible Sensing Material with High Force and Thermal Sensitivity Based on GaInSn in Capillary Embedded in PDMS

by Fandou Bao, Fengyao Ni, Qianqian Zhai, Zhizhuang Sun, Xiaolin Song and Yu Lin

Polymers 2024, 16(23), 3426; https://doi.org/10.3390/polym16233426 - 5 Dec 2024

Viewed by 836

Abstract

Flexible sensing materials have become a hot topic due to their sensitive electrical response to external force or temperature and their promising applications in flexible wear and human–machine interaction. In this study, a PDMS/capillary GaInSn flexible sensing material with high force and thermal [...] Read more.

Flexible sensing materials have become a hot topic due to their sensitive electrical response to external force or temperature and their promising applications in flexible wear and human–machine interaction. In this study, a PDMS/capillary GaInSn flexible sensing material with high force and thermal sensitivity was prepared utilizing liquid metal (LM, GaInSn), flexible silicone capillary, and polydimethylsiloxane (PDMS). The resistance (R) of the flexible sensing materials under the action of different forces and temperatures was recorded in real-time. The electrical performance results confirmed that the R of the sensing material was responsive to temperature changes and increased with the increasing temperature, indicating its ability to transmit temperature signals into electrical signals. The R was also sensitive to the external force, such as cyclic stretching, cyclic compression, cyclic bending, impact and rolling. The ΔR/R₀ changed periodically and stably with the cyclic stretching, cyclic compression and cyclic bending when the conductive pathway diameter was 0.5–1.0 mm, the cyclic tensile strain ≤ 20%, the cyclic tensile rate ≤ 2.0 mm/min, the compression ratio ≤ 0.5, and the relative bending curvature ≤ 0.16. Moreover, the material exhibited sensitivity in detecting biological signals, such as the joint movements of the finger, wrist, elbow and the stand up-crouch motion. In conclusion, this work provides a method for preparing a sensing material with the capillary structure, which was confirmed to be sensitive to force and heat, and it produced different types of R signals under different deformations and different temperatures. Full article

(This article belongs to the Section Smart and Functional Polymers)

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16 pages, 8181 KiB

Open AccessArticle

The Neutron Absorption Capacity of a Composite Material Based on Ultrahigh Molecular Weight Polyethylene Under Reactor Radiation Conditions

by Mazhyn Skakov, Baurzhan Tuyakbayev, Yernat Kozhakhmetov and Yerzhan Sapatayev

Polymers 2024, 16(23), 3425; https://doi.org/10.3390/polym16233425 - 5 Dec 2024

Viewed by 658

Abstract

This work presents the results of a study on the influence of fillers on the neutron absorption capacity of materials made from ultra-high molecular weight polyethylene (UHMWPE). Composite materials based on UHMWPE were obtained using gas-flame technology with the addition of powdered UHMWPE [...] Read more.

This work presents the results of a study on the influence of fillers on the neutron absorption capacity of materials made from ultra-high molecular weight polyethylene (UHMWPE). Composite materials based on UHMWPE were obtained using gas-flame technology with the addition of powdered UHMWPE fillers (H₃BO₃, WC, and PbO). A radiation cassette has been developed and constructed for conducting studies on the neutron absorption capacity of the material, allowing for the placement of a sample with activation indicators. Samples of UHMWPE with fillers were irradiated at different doses on the unique research reactor IVG-1M, located at the National Nuclear Center of the Republic of Kazakhstan in the city of Kurchatov. The reaction rate of ⁶³Cu (n, g), ⁶⁴Cu and ⁵⁸Ni (n, p)⁵⁸Co on activation indicators and neutron flux density at the sample location were determined. Neutron-physical and thermal-physical calculations were performed in order to determine their characteristics. The structure and phase state of UHMWPE with fillers were studied before and after irradiation. Full article

(This article belongs to the Section Polymer Physics and Theory)

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14 pages, 3498 KiB

Open AccessArticle

An OpenSees Surrogate Constitutive Model for High-Damping Rubber Based on Machine Learning

by Feng Li and Tianbo Peng

Polymers 2024, 16(23), 3424; https://doi.org/10.3390/polym16233424 - 5 Dec 2024

Viewed by 743

Abstract

The complex mechanical properties of high-damping rubber (HDR), a commonly used seismic isolation material in buildings and bridges, present a significant challenge in civil engineering. In a previous study, the authors proposed an HDR constitutive model that combines a Gated Recurrent Unit (GRU) [...] Read more.

The complex mechanical properties of high-damping rubber (HDR), a commonly used seismic isolation material in buildings and bridges, present a significant challenge in civil engineering. In a previous study, the authors proposed an HDR constitutive model that combines a Gated Recurrent Unit (GRU) and an attention mechanism, offering novel insights into the mechanical properties of HDR. The constitutive model was simplified first to facilitate the deployment of the proposed constitutive model within the finite element analysis environment. Then, the simplified constitutive model was converted into a uniaxial material format suitable for use within the open system for earthquake engineering simulation (OpenSees). In OpenSees, the uniaxial material was named HDRGA material, and the code for the HDRGA material header and source files was written. Finally, an HDR surrogate constitutive model was developed in OpenSees. To validate the precision of the HDRGA material in characterizing the mechanical attributes of HDR, a two-node model and a single-pier model were devised, and their accuracy was verified through a comparative analysis of test results and nonlinear time history calculation results, respectively. The results demonstrate that the developed HDRGA material is capable of performing well under earthquakes. Full article

(This article belongs to the Special Issue Advances in Functional Rubber and Elastomer Composites II)

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32 pages, 13451 KiB

Open AccessArticle

Nanocomposites Based on Disentangled Ultra-High Molecular Weight Polyethylene: Aspects and Specifics of Solid-State Processing

by Oleg V. Lebedev, Ekaterina P. Tikunova, Tikhon S. Kurkin, Evgeny K. Golubev and Alexander N. Ozerin

Polymers 2024, 16(23), 3423; https://doi.org/10.3390/polym16233423 - 5 Dec 2024

Viewed by 648

Abstract

The stages of solid-state processing of nanocomposites, based on nascent disentangled ultra-high-molecular-weight polyethylene (d-UHMWPE) reactor powders (RPs) and carbon nanoparticles (NPs) of various types, were meticulously investigated. The potential for optimizing the filler distribution through variation of the processing parameters, and the impact [...] Read more.

The stages of solid-state processing of nanocomposites, based on nascent disentangled ultra-high-molecular-weight polyethylene (d-UHMWPE) reactor powders (RPs) and carbon nanoparticles (NPs) of various types, were meticulously investigated. The potential for optimizing the filler distribution through variation of the processing parameters, and the impact of the d-UHMWPE RP and nanofiller type on the electrical conductivity of the resulting composites were discussed. The specifics of the dependences of conductivity and tensile strength on the deformation ratio for the composites, oriented under homogeneous shear conditions, were investigated. The obtained results and the results on piezoresistivity and temperature dependency of conductivity in the oriented and compacted composites demonstrated the independence of the UHMWPE matrix orientational strengthening on the filling. The interchangeability of high-temperature uniaxial deformation and deformation under homogeneous conditions for orientational strengthening and electrical conductivity changes in the preliminary oriented composite samples was confirmed. The potential for simultaneously achieving high strength and conductivity in composite tapes and the possibility of directly processing d-UHMWPE RP and NPs mixtures into oriented composite tapes were demonstrated. The overall results suggest that the studied composites may serve as a viable model system for investigating the deformational behavior of conductive networks comprising NPs of varying types and contents. Full article

(This article belongs to the Special Issue Polymer Composites for Electrical and Electronic Engineering Applications, 2nd Edition)

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14 pages, 4034 KiB

Open AccessArticle

In Situ Thermosensitive Mucoadhesive Nasal Gel Containing Sumatriptan: In Vitro and Ex Vivo Evaluations

by Aseel Alshraim, Doaa Alshora, Lubna Ashri, Ahlam Alhusaini, Nawal Alanazi and Nisreen M. Safwan

Polymers 2024, 16(23), 3422; https://doi.org/10.3390/polym16233422 - 5 Dec 2024

Viewed by 820

Abstract

The aim of this study was to develop a thermosensitive mucoadhesive (MA) in situ nasal gel for sumatriptan. A 3D response surface methodology (Design of Expert version 11) was employed to formulate nine different formulations. The Pluronic F-127 concentration (X1) and chitosan concentration [...] Read more.

The aim of this study was to develop a thermosensitive mucoadhesive (MA) in situ nasal gel for sumatriptan. A 3D response surface methodology (Design of Expert version 11) was employed to formulate nine different formulations. The Pluronic F-127 concentration (X1) and chitosan concentration (X2) were selected as independent factors. The formulas were studied in terms of pH, clarity, drug content, gelation temperature, gelation time, gel strength, MA strength, viscosity, % release after 5 h, and release kinetics. The optimized formulas were studied for % permeated after 5 h and stability in addition to previous tests. The study of the stability of the optimized formula was performed under accelerated conditions (40 ± 2 °C, 75 ± 5% RH) for 3 months. The outcomes of the optimized formula were a clear gel with a gelation temperature of 33 °C and a reasonable gelation time of less than one minute, and the release and permeation during 5 h were 40% and 50%, respectively. The formulated gel decreased the mucociliary clearance (MCC) and thus increased the retention time in the nasal cavity, resulting in enhancing SMT absorption, which could improve the drug efficacy. Full article

(This article belongs to the Special Issue Functional Gel and Their Multipurpose Applications)

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16 pages, 6214 KiB

Open AccessArticle

The Application of Porous Carbon Derived from Furfural Residue as the Electrode Material in Supercapacitors

by Zhiyin Zhang, Huimin Hu, Jie Yang, Zhengguang He, Guangyue Zhu and Chang Wen

Polymers 2024, 16(23), 3421; https://doi.org/10.3390/polym16233421 - 5 Dec 2024

Viewed by 728

Abstract

Resource use is crucial for the sustainable growth of energy and green low-carbon applications since the improper handling of biomass waste would have a detrimental effect on the environment. This paper used nano-ZnO and ammonium persulfate ((NH₄)₂S₂O [...] Read more.

Resource use is crucial for the sustainable growth of energy and green low-carbon applications since the improper handling of biomass waste would have a detrimental effect on the environment. This paper used nano-ZnO and ammonium persulfate ((NH₄)₂S₂O₈, APS) as a template agent and heteroatom dopant, respectively. Using a one-step carbonization process in an inert atmosphere, the biomass waste furfural residue (FR) was converted into porous carbon (PC), which was applied to the supercapacitor electrode. The impact of varying APS ratios and carbonization temperatures on the physicochemical properties and electrochemical properties of PC was studied. O, S, and N atoms were evenly distributed in the carbon skeleton, producing abundant heteroatomic functional groups. The sample with the largest specific surface area (SSA, 855.62 m² g⁻¹) was made at 900 °C without the addition of APS. With the increase in adding the ratio of APS, the SSA and pore volume of the sample were reduced, owing to the combination of APS and ZnO to form ZnS during the carbonization process, which inhibited the pore generation and activation effect of ZnO and damaged the pore structure of PC. At 0.5 A g⁻¹ current density, PC900-1 (FR: ZnO: APS ratio 1:1:1, prepared at 900 °C) exhibited the maximum specific capacitance of 153.03 F g⁻¹, whereas it had limited capacitance retention at high current density. PC900-0.1 displayed high specific capacitance (141.32 F g⁻¹ at 0.5 A g⁻¹), capacitance retention (80.7%), low equivalent series resistance (0.306 Ω), and charge transfer resistance (0.145 Ω) and showed good rate and energy characteristics depending on the synergistic effect of the double layer capacitance and pseudo-capacitance. In conclusion, the prepared FR-derived PC can meet the application of a supercapacitor energy storage field and realize the resource and functional utilization of biomass, which has a good application prospect. Full article

(This article belongs to the Special Issue Processing, Valorization and Utilization of Biomass/Waste-Derived Polymers)

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40 pages, 18711 KiB

Open AccessArticle

Testing, Experimental Design, and Numerical Analysis of Nanomechanical Properties in Epoxy Hybrid Systems Reinforced with Carbon Nanotubes and Graphene Nanoparticles

by Giovanni Spinelli, Rosella Guarini, Todor Batakliev, Liberata Guadagno and Marialuigia Raimondo

Polymers 2024, 16(23), 3420; https://doi.org/10.3390/polym16233420 - 5 Dec 2024

Viewed by 929

Abstract

Hybrid nanocomposites incorporating multiple fillers are gaining significant attention due to their ability to enhance material performance, offering superior properties compared to traditional monophase systems. This study investigates hybrid epoxy-based nanocomposites reinforced with multi-walled carbon nanotubes (MWCNTs) and graphene nanosheets (GNs), introduced at [...] Read more.

Hybrid nanocomposites incorporating multiple fillers are gaining significant attention due to their ability to enhance material performance, offering superior properties compared to traditional monophase systems. This study investigates hybrid epoxy-based nanocomposites reinforced with multi-walled carbon nanotubes (MWCNTs) and graphene nanosheets (GNs), introduced at two different weight concentrations of the mixed filler, i.e., 0.1 wt% and 0.5 wt% which are, respectively, below and above the Electrical Percolation Threshold (EPT) for the two binary polymer composites that solely include one of the two nanofillers, with varying MWCNTs:GNs ratios. Mechanical properties, such as contact depth, hardness, and reduced modulus, were experimentally assessed via nanoindentation, while morphological analysis supported the mechanical results. A Design of Experiments (DoE) approach was utilized to evaluate the influence of filler concentrations on the composite’s mechanical performance, and Response Surface Methodology (RSM) was applied to derive a mathematical model correlating the filler ratios with key mechanical properties. The best and worst-performing formulations, based on hardness and contact depth results, were further investigated through detailed numerical simulations using a multiphysics software. After validation considering experimental data, the simulations provided additional insights into the mechanical behavior of the hybrid composites. This work aims to contribute to the knowledge base on hybrid composites and promote the use of computational modeling techniques for optimizing the design and mechanical performance of advanced materials. Full article

(This article belongs to the Special Issue Epoxy Polymers and Composites)

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