Polymers最新文献

{"title":"The Influence of Conditions of Polycondensation in Acid Medium on the Structure of Oligosilsesquioxanes with a Novel Eugenol-Containing Substituent.","authors":"Alexander D Ageenkov, Nikolay S Bredov, Anna A Shcherbina, Ramil R Khasbiullin, Anton S Tupikov, Mikhail A Soldatov","doi":"10.3390/polym16202951","DOIUrl":"https://doi.org/10.3390/polym16202951","url":null,"abstract":"<p><p>Eugenol-containing oligoorganosilsesquioxanes were synthesized by the method of hydrolytic polycondensation in an active medium under various reaction conditions. The obtained products were characterized by ²⁹Si NMR spectroscopy and MALDI-TOF spectrometry. It was shown that factors such as the reaction temperature, polycondensation duration, and molar ratio between the initial alkoxysilane monomer and acetic acid may affect the molecular weight characteristics and molecular structure of the formed oligomer, like the content of stressed cyclic units (T₃, DTT, TDT) and unstressed silsesquioxane units T_nD_m. In particular, an increase in the ratio of the initial reagents led to an increase in the content of silsesquioxane T_n fragments from 28.2%_mol to 41.7%_mol, while the number of strained cyclic structures decreased by more than two times. An increase in the synthesis time is of no particular practical value since it was found that the composition of the oligomers synthesized for 6 h and 12 h was practically identical, as was that of the oligomers synthesized for 24 h and 48 h. A noticeable transition in the oligomer composition was observed only when the synthesis time was changed from 12 h to 24 h. Finally, it was shown that the choice of synthesis temperature had the strongest effect on the oligomer composition. The oligomer synthesized at 95 °C contained the highest amount of silsesquioxane T_n fragments, >77%_mol, while a T_n fragment content of ~42%_mol was observed during the synthesis at 117 °C. It was shown that silsesquioxanes are devitrified at room temperature (T_g from -6.4 to -10.6 °C), and their thermal stability in an inert atmosphere is 300 °C. The synthesized oligomers, due to the presence of hydroxyl-containing eugenol units, may be promising binders and additives for functional epoxy-silicone paints and coating materials.</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":null,"pages":null},"PeriodicalIF":4.7,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11510820/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142506643","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":"Physical, Mechanical, and Flammability Properties of Wood-Plastic Composites (WPC) Containing Beech-Wood Flour and Flame-Retardant Additives.","authors":"Yalçın Boztoprak","doi":"10.3390/polym16202944","DOIUrl":"https://doi.org/10.3390/polym16202944","url":null,"abstract":"<p><p>This study aims to develop a recyclable, economical, and flame-retardant composite material using polypropylene, beech flour, tetrabromobisphenol A bis (TBBPA), and antimony trioxide (ATO). Flame-retardant additives (TBBPA and ATO) were initially added into polypropylene at different rates, and masterbatch (MB) samples were produced by the extrusion method. Subsequently, different percentages of wood flour (10%, 15%, 20%, 25%, and 30%) along with 60% MB were added to the polypropylene to create wood-polymer composites (WPC) using the injection method. The TBBPA, ATO, and wood flour were introduced through side-feeding hoppers during injection to ensure a homogeneous distribution within the WPC. Physical, thermal, and mechanical tests were conducted on the WPC samples. Additionally, TGA, FTIR, and SEM analyses were performed. The results indicated that the optimal ratios for TBBPA and ATO additives were 20% and 10%, respectively. It was observed that increasing the wood flour content in the WPC samples led to enhanced density, water absorption, hardness, impact, and abrasion resistance. Conversely, MFI, bending strength, and tensile strength decreased with higher wood flour content. It was observed that WPC samples exhibited flame resistance up to 725 °C. The produced WPC materials can be used in flooring applications, interior furniture, decorative wall panels, and aesthetic structural elements due to their fire behavior, good mechanical properties, low water-absorption rates, and aesthetic appearance.</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":null,"pages":null},"PeriodicalIF":4.7,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11511144/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142506609","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":"Polymer-Modified Fertilizers for Mitigating Strawberry Root Burn.","authors":"Ibragim Bamatov, Kirill Perevertin, Nadezda Vasilyeva","doi":"10.3390/polym16202950","DOIUrl":"https://doi.org/10.3390/polym16202950","url":null,"abstract":"<p><p>Polymer-modified fertilizers (PMFs) with prolonged nutrient release present a promising solution to address the challenges associated with conventional fertilization practices, particularly for sensitive crops such as strawberries. This study investigates the effectiveness of biodegradable PMFs in maintaining nutrient availability at optimal levels while minimizing root burn and nutrient losses. In a factorial field experiment, we obtaineda total of 3780 sets of parallel measured time series for soil EC, moisture, and temperature as well as two sets of harvest data to evaluate the impact of varying concentrations of polyvinyl alcohol (PVA) on the nutrient release rates from complex NPK fertilizer and monoammonium phosphate. Results indicate that polymer modifications significantly slow down nutrient release, leading to optimal salt levels and maximizing yield while remaining low enough to prevent the risk of root burn (EC of soil solution below 1 mS/cm). Consequently, the application of PMFs enhances strawberry yield surplus (on average 2.8 times in the second harvest) by ensuring a steady supply of nutrients throughout the growing season without inducing stress, which reduces the yield by nearly half. This research provides valuable insights into the development of more effective fertilization strategies for strawberry cultivation and other sensitive crops using PMFs.</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":null,"pages":null},"PeriodicalIF":4.7,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11511263/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142506611","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":"Corrosion Properties of the Composite Coatings Formed on PEO Pretreated AlMg3 Aluminum Alloy by Dip-Coating in Polyvinylidene Fluoride-Polytetrafluoroethylene Suspension.","authors":"Vladimir S Egorkin, Igor E Vyaliy, Andrey S Gnedenkov, Ulyana V Kharchenko, Sergey L Sinebryukhov, Sergey V Gnedenkov","doi":"10.3390/polym16202945","DOIUrl":"https://doi.org/10.3390/polym16202945","url":null,"abstract":"<p><p>This paper presents the results of an evaluation of corrosion properties of PEO pretreated AlMg3 aluminum alloy samples with polymer coatings obtained by dip-coating in a suspension of superdispersed polytetrafluoroethylene (SPTFE) in a solution of polyvinylidene fluoride (PVDF) in N-methyl-2-pyrrolidone at different PVDF:SPTFE ratios (1:1, 1:3, 1:5, and 1:10). The electrochemical tests showed that samples with a coating formed at a ratio of PVDF to SPTFE of 1:5 possessed the best corrosion properties. The corrosion current density of these samples was more than five orders of magnitude lower than this parameter for bare aluminum alloy. During the 40-day salt spray test (SST) for samples prepared in a suspension at a PVDF:SPTFE ratio of 1:1-1:5, the formation of any pittings or defects was not detected. The PVDF:SPTFE 1:5 sample demonstrated, as a result of the 40-day SST, an increase in corrosion current density of less than an order of magnitude. The evolution of the protective properties of the studied samples was assessed by a two-year field atmospheric corrosion test on the coast of the Sea of Japan. It was revealed that the samples with the PVDF:SPTFE 1:5 coating had electrochemical parameters that remained consistently high throughout the one year of exposure. After this period, the polymer layer was destroyed, which led to a deterioration in the protective characteristics of the coatings.</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":null,"pages":null},"PeriodicalIF":4.7,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11511163/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142506534","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 Multivitamins on the Color Stability of Dental Materials Used in Pediatric Dentistry: An In Vitro Study.","authors":"María Arregui, Josefina Del Pilar Contreras Arellano, Ana Veloso Durán, Francisco Guinot Jimeno","doi":"10.3390/polym16202948","DOIUrl":"https://doi.org/10.3390/polym16202948","url":null,"abstract":"<p><p>The longevity and acceptance of aesthetic dental materials are directly proportional to color stability. The aim of this study was to analyze the relationship between the use of multivitamins and the color stability of dental restorative materials. A total of 45 discs of nanohybrid composite, 45 of Reinforced Glass Ionomer (RGI), and 45 of Giomer were prepared. Subsequently, the samples were randomly divided into three solution groups (n = 15): Group 1-Sambucol Pediatric Syrup, Group 2-Hidropolivital Baby Drops, and Group 3-artificial saliva, which is preparation for patients with xerostomia. For 28 days, the specimens were immersed in 10 mL of each multivitamin for two minutes every 24 h. Color measurements were repeated on days 7, 14, 21, and 28. Statistical analysis was performed using the Jamovi software version 2.2.5, employing the Shapiro-Wilk test for normality and the Kruskal-Wallis test for non-parametric data. When comparing materials, statistically significant differences (<i>p</i> < 0.001) were observed between RGI and Giomer, and RGI and composite, but not between Giomer and composite (<i>p</i> = 0.716). The highest change was observed in RGI-Hidropolivital ΔE₀₀ = 3.27 (2.38-4.59) and the least in composite-Sambucol ΔE₀₀ = 0.72 (0.30-1.18). In conclusion, the exposure time and the multivitamin influence the color change of restorative materials.</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":null,"pages":null},"PeriodicalIF":4.7,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11510919/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142506540","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":"Phenylethynyl-Terminated Imide Oligomer-Based Thermoset Resins.","authors":"Minju Kim, Kiyeong Kim, Joon Hyuk Lee, Eunkyung Jeon, Jungkun Song, Jaeho Choi, Hyeonuk Yeo, Ki-Ho Nam","doi":"10.3390/polym16202947","DOIUrl":"https://doi.org/10.3390/polym16202947","url":null,"abstract":"<p><p>Phenylethynyl-terminated imide (PETI) oligomers are highly valued for their diverse applications in films, moldings, adhesives, and composite material matrices. PETIs can be synthesized at varying molecular weights, enabling the fine-tuning of their properties to meet specific application requirements. Upon thermal curing, these oligomers form super-rigid network structures that enhance solvent resistance, increase glass-transition temperatures, and improve elastic moduli. Their low molecular weights and melt viscosities further facilitate processing, making them particularly suitable for composites and adhesive bonding. This review examines recent advancements in developing ultra-high-temperature PETIs, focusing on their structure-processing-properties relationships. It begins with an overview of the historical background and key physicochemical characteristics of PETIs, followed by a detailed discussion of PETIs synthesized from monomers featuring noncoplanar configurations (including kink and cardo structures), fluorinated groups, flexible linkages, and liquid crystalline mesogenic structures. The review concludes by addressing current challenges in this research field and exploring potential future directions.</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":null,"pages":null},"PeriodicalIF":4.7,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11511106/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142506608","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":"Preparation of Montmorillonite-Melamine Cyanurate and Inhibition of the Emission of Phosphine from PA6/Aluminum Hypophosphate.","authors":"Lin Wang, Yuyang Li, Chenyang Yan, Xiangmei Li, Jiyu He, Rongjie Yang","doi":"10.3390/polym16202946","DOIUrl":"https://doi.org/10.3390/polym16202946","url":null,"abstract":"<p><p>In order to mitigate the release of toxic phosphine from aluminum hypophosphite in twin-screw processing, montmorillonite-melamine cyanurate was prepared by three methods: (1) mechanical intercalation, (2) water intercalation and (3) in situ intercalation. The sheet spacing of montmorillonite was increased from 1.140 nm to 1.141 nm, 1.208 nm and 1.217 nm for these three methods, respectively, and scanning electron microscope (SEM) and transmission electron microscopy (TEM) proved that melamine cyanurate was successfully inserted into the montmorillonite sheets. The montmorillonite-melamine cyanurate from in situ intercalation can best inhibit the release of PH₃ from aluminum hypophosphite, and the peaks of phosphine, mean values of phosphine and integral of phosphine were reduced by 81.9%, 72.1% and 72.2%, respectively. The mode of action of montmorillonite-melamine cyanuric inhibition of the emission of phosphine from aluminum hypophosphite can be attributed to the physical absorption of montmorillonite and the chemical bonding of melamine cyanurate. In addition, in situ intercalation can slightly improve flame retardancy, attributed to incomplete exfoliation of montmorillonite sheets.</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":null,"pages":null},"PeriodicalIF":4.7,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11511171/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142506619","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":"Role of Sterilization on In Situ Gel-Forming Polymer Stability.","authors":"Elena O Bakhrushina, Alina M Afonina, Iosif B Mikhel, Natalia B Demina, Olga N Plakhotnaya, Anastasiya V Belyatskaya, Ivan I Krasnyuk, Ivan I Krasnyuk","doi":"10.3390/polym16202943","DOIUrl":"https://doi.org/10.3390/polym16202943","url":null,"abstract":"<p><p>In recent years, stimulus-sensitive drug delivery systems have been developed for parenteral administration as a depot system. In situ systems incorporate smart polymers that undergo a phase transition at the site of administration. All parenteral and ocular dosage forms must meet sterility requirements. Careful selection of the sterilization method is required for any type of stimuli-sensitive system. Current sterilization methods are capable of altering the conformation of polymers or APIs to a certain extent, ultimately causing the loss of pharmacological and technological properties of the drug. Unfortunately, the issues of risk assessment and resolution regarding the sterilization of stimuli-sensitive systems, along with ways to stabilize such compositions, are insufficiently described in the scientific literature to date. This review provides recommendations and approaches, formulated on the basis of published experimental data, that allow the effective management of risks arising during the development of in situ systems requiring sterility.</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":null,"pages":null},"PeriodicalIF":4.7,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11510731/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142506632","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":"Chemical and Resistive Switching Properties of <i>Elaeodendron buchananii</i> Extract-Carboxymethyl Cellulose Composite: A Potential Active Layer for Biodegradable Memory Devices.","authors":"Zolile Wiseman Dlamini, Sreedevi Vallabhapurapu, Jennifer Nambooze, Anke Wilhelm, Elizabeth Erasmus, Refilwe Mogale, Marthinus Rudi Swart, Vijaya Srinivasu Vallabhapurapu, Bheki Mamba, Wendy Setlalentoa, Tebogo Sfiso Mahule, Vanessa de Oliveira Arnoldi Pellegrini, Shaun Cronje, Igor Polikarpov","doi":"10.3390/polym16202949","DOIUrl":"https://doi.org/10.3390/polym16202949","url":null,"abstract":"<p><p>Biodegradable electronic devices play a crucial role in addressing the escalating issue of electronic waste accumulation, which poses significant environmental threats. In this study, we explore the utilization of a methanol-based extract of the <i>Elaeodendron buchananii</i> plant blended with a carboxymethyl cellulose biopolymer to produce a biodegradable and environmentally friendly functional material for a resistive switching memory system using silver and tungsten electrodes. Our analyses revealed that these two materials chemically interact to generate a perfect composite with near semiconducting optical bandgap (4.01 eV). The resultant device exhibits O-type memory behavior, with a low ON/OFF ratio, strong endurance (≥103 write/erase cycles), and satisfactory (≥103) data retention. Furthermore, through a comprehensive transport mechanism analysis, we observed the formation of traps in the composite that significantly improved conduction in the device. In addition, we established that altering the voltage amplitude modifies the concentration of traps, leading to voltage amplitude-driven multiple resistance states. Overall, our findings underscore the potential of functionalizing polymers that can be functionalized by incorporating plant extracts, resulting in biodegradable and nonvolatile memory devices with promising performance metrics.</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":null,"pages":null},"PeriodicalIF":4.7,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11511324/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142506555","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":"Enhanced Photovoltaic Performance of Poly(3,4-Ethylenedioxythiophene)Poly(<i>N</i>-Alkylcarbazole) Copolymer-Based Counter Electrode in Dye-Sensitized Solar Cells.","authors":"Sherif Dei Bukari, Aliya Yelshibay, Bakhytzhan Baptayev, Mannix P Balanay","doi":"10.3390/polym16202941","DOIUrl":"https://doi.org/10.3390/polym16202941","url":null,"abstract":"<p><p>Conducting polymers are emerging as promising alternatives to rare and expensive platinum for counter electrodes in dye-sensitized solar cells; due to their ease of synthesis, they can be chemically tuned and are suitable for roll-to-roll production. Among these, poly (3,4-ethylenedioxythiophene) (PEDOT)-based counter electrodes have shown leading photovoltaic performance. However, certain conductivity issues remain that affect the effectiveness of these counter electrodes. In this study, we present an electropolymerized PEDOT and poly(<i>N</i>-alkylated-carbazole) copolymer as an efficient electrocatalyst for the reduction in I3- in dye-sensitized solar cells. Copolymerization with <i>N</i>-alkylated carbazoles significantly increases the conductivity of the polymer film and facilitates rapid charge transport at the interface between the polymer electrode and the electrolyte. The length of the alkyl substituents also plays a crucial role in this improvement. Electrochemical analysis showed a reduction in charge transport resistance from 3.31 Ω·cm² for PEDOT to 2.26 Ω·cm² for the PEDOT:poly(<i>N</i>-octylcarbazole) copolymer, which is almost half the resistance of a platinum-based counter electrode (4.12 Ω·cm²). Photovoltaic measurements showed that the solar cell with the PEDOT:poly(<i>N</i>-octylcarbazole) counter electrode achieved an efficiency of 8.88%, outperforming both PEDOT (7.90%) and platinum-based devices (7.57%).</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":null,"pages":null},"PeriodicalIF":4.7,"publicationDate":"2024-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11510948/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142506559","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}