Polymers最新文献

{"title":"Efficient Prediction of Fatigue Damage Analysis of Carbon Fiber Composites Using Multi-Timescale Analysis and Machine Learning.","authors":"Satoru Yoshimori, Jun Koyanagi, Ryosuke Matsuzaki","doi":"10.3390/polym16233448","DOIUrl":"https://doi.org/10.3390/polym16233448","url":null,"abstract":"<p><p>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.</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":"16 23","pages":""},"PeriodicalIF":4.7,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142838978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Friction Behaviors and Wear Mechanisms of Carbon Fiber Reinforced Composites for Bridge Cable.","authors":"Guijun Xian, Xiao Qi, Rui Guo, Jingwei Tian, Huigang Xiao, Chenggao Li","doi":"10.3390/polym16233446","DOIUrl":"https://doi.org/10.3390/polym16233446","url":null,"abstract":"<p><p>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.</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":"16 23","pages":""},"PeriodicalIF":4.7,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142838815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correction: Habib et al. Thiolated Chitosan Microneedle Patch of Levosulpiride from Fabrication, Characterization to Bioavailability Enhancement Approach. <i>Polymers</i> 2022, <i>14</i>, 415.","authors":"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, Mohamed M Abdel-Daim","doi":"10.3390/polym16233445","DOIUrl":"https://doi.org/10.3390/polym16233445","url":null,"abstract":"<p><p>In the original publication [...].</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":"16 23","pages":""},"PeriodicalIF":4.7,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142838904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Alfalfa/Lucerne (<i>Medicago sativa</i>) as a Source of Functional Bioadditives for Elastomeric Natural Rubber Composites.","authors":"Justyna Miedzianowska-Masłowska, Marcin Masłowski, Krzysztof Strzelec","doi":"10.3390/polym16233444","DOIUrl":"https://doi.org/10.3390/polym16233444","url":null,"abstract":"<p><p>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.</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":"16 23","pages":""},"PeriodicalIF":4.7,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142838908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of Modified PVA Fiber on Ultra-High Performance Concrete and Its Enhancing Mechanism.","authors":"Zhiyuan Chen, Hongyu Fan, Wanying Zheng, Siheng Zhang, Xi Wu, Tengfei Fu, Demei Yu","doi":"10.3390/polym16233449","DOIUrl":"https://doi.org/10.3390/polym16233449","url":null,"abstract":"<p><p>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.</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":"16 23","pages":""},"PeriodicalIF":4.7,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142839040","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Sizing Agents and Resin-Formulated Matrices with Varying Stiffness-Toughness Ratios on the Properties of Carbon Fiber Epoxy Resin Composites.","authors":"Pengfei Song, Qianli Fang, Wen Liu, Xinyue Ma, Qingchao Li, Mehraj-Ud-Din Naik, Mudasir Ahmad, Guoqing Huang, Chuncai Yang","doi":"10.3390/polym16233447","DOIUrl":"https://doi.org/10.3390/polym16233447","url":null,"abstract":"<p><p>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.</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":"16 23","pages":""},"PeriodicalIF":4.7,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142838972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Compatibilizer Efficiency in Enhancing Marine Plastic Waste Valorization Through Simulated Recycled Plastic Blends.","authors":"Sibele Piedade Cestari, Pedro Veiga Rodrigues, Ana Cristina Ribeiro, Maria Cidália Rodrigues Castro, Vasco Cruz, Ana Rita Torres, Nuno Ramos, Ana Vera Machado","doi":"10.3390/polym16233441","DOIUrl":"https://doi.org/10.3390/polym16233441","url":null,"abstract":"<p><p>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.</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":"16 23","pages":""},"PeriodicalIF":4.7,"publicationDate":"2024-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142838895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Finite Element Method in Thermosetting Polymers' and FRPs' Supramolecular Structure and Thermomechanical Properties' Modeling.","authors":"Alexander Korolev, Alexander Zadorin, Maxim Mishnev","doi":"10.3390/polym16233443","DOIUrl":"https://doi.org/10.3390/polym16233443","url":null,"abstract":"<p><p>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.</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":"16 23","pages":""},"PeriodicalIF":4.7,"publicationDate":"2024-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142838710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advances in Multifunctional Polymer-Based Nanocomposites.","authors":"Jia-Wun Li, Chih-Chia Cheng, Chih-Wei Chiu","doi":"10.3390/polym16233440","DOIUrl":"https://doi.org/10.3390/polym16233440","url":null,"abstract":"<p><p>\"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 [...].</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":"16 23","pages":""},"PeriodicalIF":4.7,"publicationDate":"2024-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142838903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of Lignin Type on the Properties of Hemp Fiber-Reinforced Polypropylene Composites.","authors":"Florin Ciolacu, Teodor Măluțan, Gabriela Lisa, Mariana Ichim","doi":"10.3390/polym16233442","DOIUrl":"https://doi.org/10.3390/polym16233442","url":null,"abstract":"<p><p>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.</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":"16 23","pages":""},"PeriodicalIF":4.7,"publicationDate":"2024-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142839036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}