Polymers最新文献

{"title":"Incorporating Non-Linear Epoxy Resin Development in Infusion Simulations: A Dual-Exponent Viscosity Model Approach.","authors":"Mohammad W Tahir, Umar Khan, Jan-Peter Schümann","doi":"10.3390/polym17050657","DOIUrl":"10.3390/polym17050657","url":null,"abstract":"<p><p>In the field of liquid composite moulding (LCM) simulations, a long-standing assumption has dominated-the belief in constant resin viscosity. While effective in many cases, this assumption may not hold for the infusion process, which lasts for an extended period. This impacts the mechanical properties of the cured epoxy, which are crucial for load transfer in polymer structures. The majority of epoxy resins operate on a bipartite foundation, wherein their viscosity undergoes dynamic alterations during the process of cross-linking. Temperature and cross-linking intricately interact, with elevated temperatures initially reducing viscosity due to kinetic energy but later increasing it as cross-linking accelerates. This interplay significantly influences the efficiency of the infusion process, especially in large and intricate moulds. This article explores the significant temperature dependence of epoxy resin viscosity, proposing an accurate model rooted in its non-linear evolution. This model aligns with empirical evidence, offering insights into determining the optimal starting temperature for efficient mould filling. This study presents an advanced infusion model that extends existing non-linear dual-split viscosity approaches by incorporating the experimental validation of viscosity variations. Unlike previous models that primarily focus on theoretical or numerical frameworks, this work integrates experimental insights to optimize infusion temperature for efficient resin infusion in large and complex parts. Building on these findings, a novel mould-filling technique is proposed to enhance efficiency and reduce material waste.</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":"17 5","pages":""},"PeriodicalIF":4.7,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11902311/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143616895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preservation of Soil Ruins After High Temperatures: Water Absorption and Compressive Strength.","authors":"Miao Li, Yifan Zhang, Zhilin Du, Yao Zheng, Senbiao Liu, Hongjie Luo, Waraz Abdul, Jianfeng Zhu","doi":"10.3390/polym17050656","DOIUrl":"10.3390/polym17050656","url":null,"abstract":"<p><p>Soil ruins hold historical significance and serve as witnesses to past civilizations. High temperatures cause soil moisture to evaporate and soil to shrink, leading to cracking issues and making preservation a global challenge. P(AA-AM-AMPS) (Acrylic acid -Acrylamide-2-Acrylamide-2-methy-propenesulfonic acid) composites solve this problem by combining absorbent materials with loess. In this study, P(AA-AM-AMPS) was prepared using a solution method. The water absorption, water retention, air permeability, and compressive strength of P(AA-AM-AMPS) in loess were studied. The results show that after adding P(AA-AM-AMPS) to loess, there is no obvious color difference compared with the blank sample, and the air permeability of the reinforced loess is basically the same as that of the blank soil. After aging resistance tests, the surface cracking of soil clods is significantly reduced compared to that of the blank samples, and their compressive strength improved from 1.8 N/mm² to 2.6 N/mm².</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":"17 5","pages":""},"PeriodicalIF":4.7,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11902542/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143616974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deep-Neural-Networks-Based Data-Driven Methods for Characterizing the Mechanical Behavior of Hydroxyl-Terminated Polyether Propellants.","authors":"Ruohan Han, Xiaolong Fu, Bei Qu, La Shi, Yuhang Liu","doi":"10.3390/polym17050660","DOIUrl":"10.3390/polym17050660","url":null,"abstract":"<p><p>Hydroxyl-terminated polyether (HTPE) propellants are attractive in the weapons materials and equipment industry for their insensitive properties. Storage, combustion, and explosion of solid propellants are affected by their mechanical properties, so accurate mechanical modeling is vital. In this study, deep neural networks are applied to model composite solid-propellant mechanical behavior for the first time. A data-driven framework incorporating a novel training-testing splitting strategy is proposed. By building Neural Networks (FFNNs), Kolmogorov-Arnold Networks (KANs) and Long Short-Term Memory (LSTM) networks and optimizing the model framework and parameters using a Bayesian optimization algorithm, the results show that the LSTM model predicts the stress-strain curve of HTPE propellant with an RMSE of 0.053 MPa, which is 62.7% and 48.5% higher than the FFNNs and the KANs, respectively. The R² values of the LSTM model for the testing set exceed 0.99, which can effectively capture the effects of tensile rate and temperature changes on tensile strength, and accurately predict the yield point and the slope change of the stress-strain curve. Using the interpretable Shapley Additive Explanations (SHAP) method, fine-grained ammonium perchlorate (AP) can increase its tensile strength, and plasticizers can increase their elongation at break; this method provides an effective approach for HTPE propellant formulation.</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":"17 5","pages":""},"PeriodicalIF":4.7,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11902718/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143615995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Isothermal Equation of State of Polyether Ether Ketone (PEEK) by Optical Imaging Method in Diamond Anvil Cell.","authors":"Ying Chen, Ning Yang, Yi Zhang, Lei Liu","doi":"10.3390/polym17050655","DOIUrl":"10.3390/polym17050655","url":null,"abstract":"<p><p>Polymers serve as important functional materials in various environments, including high-pressure conditions. However, the behavior of polymers under high pressure is currently less understood. In this study, the isothermal equation of state of polyether ether ketone (PEEK), an important polymer, was measured using the diamond anvil cell technique at up to 8 GPa. The isotropic compression behavior of PEEK samples was investigated by monitoring the area change in PEEK disks during the compression process using the optical imaging method. The present results shed light on the mechanical properties of PEEK under extreme conditions, which will guide the applications of PEEK at high pressures.</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":"17 5","pages":""},"PeriodicalIF":4.7,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11902402/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143616934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Using Polymeric Carbon Nitride/ZrO₂ Nanocomposite for Low Salinity Water Flooding in Carbonate Porous Media at Real Reservoir Conditions.","authors":"Yaser Ahmadi, Marjan Tanzifi","doi":"10.3390/polym17050649","DOIUrl":"10.3390/polym17050649","url":null,"abstract":"<p><p>Nanoparticles and nanocomposites have been used in recent studies to improve oil reservoir recovery. With the introduction of a newly constructed smart water injection scenario, this work investigated the physicochemical characteristics of the polymeric carbon nitride/ZrO₂ nanocomposite (ZrO₂/g-C₃N₄), and the results were compared with pure ZrO₂ nanoparticles as a known enhanced oil recovery agent. The effects of ZrO₂/g-C₃N₄ and ZrO₂ on the wettability change, zeta potential, and interfacial tension under reservoir conditions (78 °C and 3800 psi) were determined after characterization experiments, which included X-ray powder diffraction (XRD), a Fourier transform infrared spectrometer (FTIR), transmission electron microscopy (TEM), a field emission scanning electron microscope (FESEM), energy-dispersive x-ray testing (EDX), and a Brunauer-Emmett-Teller (BET) analysis. Based on the highest zeta potential and the greatest reduction in the contact angle and interfacial tension, the optimum concentrations for ZrO₂/g-C₃N₄ and ZrO₂ were determined to be 30 and 40 ppm, respectively. Moreover, the ZrO₂/g-C₃N₄ nanocomposite demonstrated better results in enhancing the oil recovery parameters, and it was selected for low salinity flooding scenarios with three different salinities, including MgCl₂ + seawater (SW), CaCl₂ + SW, and MgSO₄ + SW, at 30 ppm of the nanocomposite. The best readings for the ZrO₂/g-C₃N₄ nanocomposite in its interfacial tension, contact angle, and zeta potential show that 1000 ppm has the best interfacial tension reduction among the tested concentrations of 500-50,000 ppm. At 30 ppm, MgCl₂ + SW had the maximum recovery (i.e., 49.36%), and this resulted from better interfacial tension reduction, contact angle reduction, and stability compared to other salinities.</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":"17 5","pages":""},"PeriodicalIF":4.7,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11902529/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143616992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cationized Hemp Fiber to Improve the Interfacial Adhesion in PLA Composite.","authors":"Meylí Valin Fernández, Matías Angelo Monsalves Rodríguez, Carlos Andrés Medina Muñoz, Daniel A Palacio, Angelo Giovanni Oñate Soto, José Luis Valin Rivera, Francisco Rolando Valenzuela Diaz","doi":"10.3390/polym17050652","DOIUrl":"10.3390/polym17050652","url":null,"abstract":"<p><p>3D printing with biodegradable polymers such as polylactic acid (PLA) is a sustainable alternative to conventional petroleum-derived plastics. However, improving the mechanical properties of PLA remains a challenge. This study explores the incorporation of chemically treated hemp fibers to improve the interfacial adhesion and mechanical strength of PLA filaments. Samples with PLA and hemp were prepared by subjecting the fibers to cationization treatment with (3-chloro-hydroxypropyl) tri-methylammonium (EPTA) and functionalization with glycidyl methacrylate (GMA). EPTA improves adhesion mainly through surface modification, increasing reactive functional groups in cellulose, while GMA improves interfacial adhesion by forming covalent bonds with both the fiber and PLA and improves the dispersion of the fiber in the matrix. Mechanical properties were evaluated by tensile testing, as well as fracture morphology by scanning electron microscopy (SEM) and X-ray energy dispersive analysis (EDS). The results showed that the addition of untreated hemp significantly reduced the strength of PLA, but cationization with EPTA improved interfacial adhesion and increased tensile strength by 615%. The combination of treated fibers and GMA further optimized the mechanical properties, reaching values similar to pure PLA. These findings indicate that the chemical modification of natural fibers facilitates their integration into PLA filaments for 3D printing, promoting sustainable materials without compromising mechanical performance.</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":"17 5","pages":""},"PeriodicalIF":4.7,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11902533/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143616859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Poly (Caprolactone) Introduction Site on the Network Structure and Properties of Glycidyl Azide Polymer Adhesive.","authors":"Chengzhao Tu, Zhengyuan Wang, Fengdan Zhu, Dengsheng Yang, Chang Liu, Chaofei Bai, Guoping Li, Yunjun Luo","doi":"10.3390/polym17050661","DOIUrl":"10.3390/polym17050661","url":null,"abstract":"<p><p>Copolymers of glycidyl azide polymer (GAP) and poly (caprolactone) (PCL) were obtained by introducing PCL molecular chains at both ends or side groups of GAP molecular chains, respectively. GAP/PCL elastomers were prepared via polyurethane curing reaction and compared with GAP/PCL elastomers prepared by physical blending, in order to clarify the relationship between microstructure and macroscopic properties. The results showed that no GAP and PCL phase separation was observed in the chemically bonded GAP/PCL elastomers. The elongation at break of the thermosetting GAP/PCL block copolymer elastomer increased significantly from 268% to 300% due to the increase in molecular weight between crosslinking points. The GAP/PCL graft copolymer, with its longer PCL segment length and higher segment mobility, formed microcrystalline domains within the elastomer, resulting in a significant improvement in tensile strength from 0.32 MPa to 1.07 MPa. In addition, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) revealed that the glass transition temperature of the GAP/PCL elastomer was 2.6 °C lower than that of the pure GAP elastomer, and the thermal stability was also enhanced.</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":"17 5","pages":""},"PeriodicalIF":4.7,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11902306/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143616900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Novel Intrauterine Device for the Extended Tissue-Specific Release of Estradiol and Norethindrone to Treat the Genitourinary Syndrome of Menopause.","authors":"Ahmed Abdelgader, Mershen Govender, Pradeep Kumar, Yahya E Choonara","doi":"10.3390/polym17050665","DOIUrl":"10.3390/polym17050665","url":null,"abstract":"<p><p>The genitourinary syndrome of menopause (GSM) is a prevalent condition impacting a substantial number of women globally. Presently, the management of GSM typically entails the administration of estrogen via oral, dermal, or vaginal routes for a prolonged period of time. This study involves the development of a polymer-based hollow cylindrical delivery system loaded with estradiol hemihydrate (E2) for prolonged delivery to the uterine cavity (EPHCD) combined with a norethindrone acetate (NETA)-loaded polymeric matrix (NLPM), with both units placed onto an intra-uterine device to form a multi-component drug delivery system for the management of GSM (MCDDS). In developing EPHCD, a central composite design (CCD) was employed to evaluate and optimize the impact of formulation factors on EPHCD release and unit weight loss. The optimized EPHCD was further assessed for its chemical integrity, surface morphology, hydration characteristics, release behavior, ex vivo permeation and cytocompatibility. The optimized EPHCD, which featured a high drug load (10%) and low ethyl cellulose-to-polycaprolactone ratio (EC-to-PCL, 10%), demonstrated favorable attributes with a cumulative drug release and weight loss of 23.78 ± 0.84% and 2.09 ± 0.21%, respectively, over a 4-week testing period. The release kinetics were further noted to obey the Peppas-Sahlin model. Evaluation of MCDDS revealed an in vitro drug release comparable to the individual units, with permeation studies displaying an initial increase in the rate of flux for both drugs during the first 2 h, followed by a subsequent decrease. Moreover, the MCDDS components showed good cytocompatibility against NIH/3T3 cells, with cell viability of more than 70%. Upon evaluation of the MCDDS system, the results of this study highlight its potential as a viable sustained-release intrauterine platform for the treatment of GSM.</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":"17 5","pages":""},"PeriodicalIF":4.7,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11902457/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143616835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Facile Electret Fabrication for Energy Harvesting from Human Gait.","authors":"Michele Zanoletti, Paolo Vitulo, Riccardo Morina, Daniele Callegari, Riccardo Viola, Piercarlo Mustarelli, Maddalena Patrini","doi":"10.3390/polym17050664","DOIUrl":"10.3390/polym17050664","url":null,"abstract":"<p><p>Dielectric elastomer generators (DEGs) are electrostatic transducers capable of harvesting electrical energy from oscillating mechanical parts and storing it in a battery or supercapacitor. The energy conversion element typically consists of a flexible capacitor with a variable capacitance that depends on the applied stress cycle and requires an external voltage source (bias voltage). In designing an energy harvesting device from human gait, we propose integrating two components: a dielectric elastomer fabricated using a nanocomposite polyurethane (TPU-CaCu₃Ti₄O₁₂) and an electret serving as a bias voltage source. In this work, we report on the electret fabrication and long-term charge retention properties using corona charging. The manufactured electrets are tested in coupling with the dielectric elastomer and allowed us to harvest an energy amount of 62 µJ/cycle (3.1 µJ/cm²) on a resistive load of 450 MΩ during motion cycles at a frequency of 0.5 Hz. Given the materials used, this approach is well suited to harvesting energy from human gait and holds promise for powering wearable devices.</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":"17 5","pages":""},"PeriodicalIF":4.7,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11902382/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143616906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of Gelatin-Based Renewable Packaging with <i>Melaleuca alternifolia</i> Essential Oil for Chicken Breast Preservation.","authors":"Rene Pereira de Lima, Daniela de Almeida Carrea, Vitor Augusto Dos Santos Garcia, Cristina Tostes Filgueiras, Farayde Matta Fakhouri, José Ignacio Velasco","doi":"10.3390/polym17050646","DOIUrl":"10.3390/polym17050646","url":null,"abstract":"<p><p>The aim of this study was to develop gelatin-based films incorporating Melaleuca alternifolia essential oil (MEO) and assess their application on refrigerated chicken breasts. The results showed that MEO exhibited antimicrobial activity against <i>Pseudomonas aeruginosa</i> and <i>Salmonella</i> sp., with inhibition zones of 17 mm and 9 mm, respectively. The minimum inhibitory concentration (MIC) was 10% for <i>P. aeruginosa</i> and 15% for <i>Salmonella</i> sp., demonstrating greater efficacy against <i>P. aeruginosa</i>. The antioxidant analysis using the ABTS method revealed activity of 1309 ± 18.0 μM Trolox/g, while the FRAP method resulted in 446 ± 5.78 μM FeSO₄/g. The characterization of the oil by gas chromatography identified major compounds, including 2-carene, γ-terpinene, terpine-4-ol, and α-terpineol. Incorporating the oil into gelatin films resulted in structural changes, such as an increase in thickness (from 0.059 to 0.127 mm) and water vapor permeability. Furthermore, the addition of MEO conferred homogeneous properties to the films with no visible cracks. The incorporation of MEO into gelatin films has shown ABTS antioxidant activity, and FRAP results showed a significant increase with higher MEO concentrations. The packaged samples retained more mass than the control group, which lost about 90% of its weight during storage. Texture analysis revealed only an 8% variation in the Melaleuca-coated samples compared to 19.6% in the control group. These findings indicate that gelatin films containing <i>Melaleuca</i> essential oil effectively improve the shelf life of chicken breasts.</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":"17 5","pages":""},"PeriodicalIF":4.7,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11902632/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143616881","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}