Polymers最新文献

{"title":"Enhancing Thin Film Properties of Chitosan-Collagen Biocomposites Through Potassium Silicate and Tannic Acid Integration.","authors":"Beata Kaczmarek-Szczepańska, Ugo D'Amora, Lidia Zasada, Marta Michalska-Sionkowska, Oliwia Miłek, Krzysztof Łukowicz, Anna Maria Osyczka","doi":"10.3390/polym17050608","DOIUrl":"10.3390/polym17050608","url":null,"abstract":"<p><p>Chitosan and collagen are natural polymers widely used in biomaterials science; however, their inherent low stability and solubility present several challenges to obtain formulations suitable for potential clinical applications. In this study, tannic acid (TA) was employed as a cross-linker to improve the properties of thin films made from chitosan and collagen. In addition, potassium silicate (PS) was added as an inorganic filler, to produce innovative biocomposite films. The impact of TA and PS on physicochemical (i.e., material homogeneity, surface free energy, degradation, and stability roughness of surface), antioxidant, hemocompatibility, as well as cellular responses was evaluated. The results demonstrated that the incorporation of TA significantly enhanced the physicochemical properties of the chitosan/collagen-based films. The addition of 5% PS resulted in an increase in surface free energy and a decrease in roughness parameters. Furthermore, both surface free energy and cellular responses improved with the increased TA concentration in the biocomposite firms. Meanwhile, the hemolysis rate remained below 5%, indicating the potential suitability of these materials for medical applications, such as coatings or scaffolds for bone or skin wound healing.</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":"17 5","pages":""},"PeriodicalIF":4.7,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11902633/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143616956","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":"Investigation of the Foaming Morphology of Polypropylene Molded via Microcellular Injection Assisted by Water Vapor and Gas Counter Pressure.","authors":"Shia-Chung Chen, Chao-Yuan Gan, Yan-Jun Liu, Ching-Te Feng","doi":"10.3390/polym17050611","DOIUrl":"10.3390/polym17050611","url":null,"abstract":"<p><p>The microcellular injection molding (MuCell^®) process, which uses supercritical fluid (SCF) as a foaming agent, is considered an important green molding solution to reduce product weight, molding energy, and cycle time and to improve the foam quality. However, maximizing the foaming density while keeping size uniformity in the foaming cell requires further attention. In this study, H₂O and the SCF N₂ were employed as cofoaming agents in the MuCell^® process of polypropylene (PP). Owing to the different critical points of N₂ and H₂O, bubble nucleation was expected to occur in interactive ways. Various process parameters were investigated, including the SCF N₂ content, the moisture content adsorbed within the resin under targeted PP weight reductions of 30% and 40%, the melt and mold temperature conditions, and the gas counter pressure. The resulting foaming morphology was examined to evaluate the foam quality in terms of the foaming density and bubble size distribution. The bubble coalescence, particularly in the skin layer, was examined, and the associated gas permeability flow rate was measured. The results indicated that H₂O-assisted foaming led to bubble coalescence and allowed for gas penetration in the direction of the part thickness direction, resulting in an overall increase in foaming density, particularly in the skin layer. Under high SCF N₂ and H₂O contents, the solid skin layer disappeared, regulating the gas permeability from one surface side to the other. Under the optimized process parameters, the gas permeability flow rate in the filter-like foaming PP material reached 300-450 mL/min. The application of gas counter pressure also helped increase the foam density and bubble coalescence, enhancing the gas permeability in the PP material to about 500 mL/min. These results demonstrate the potential application of microcellular injection molding using water as a cofoaming agent in moisture-release devices.</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":"17 5","pages":""},"PeriodicalIF":4.7,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11902638/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143616920","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":"Electrically Driven Liquid Crystal Elastomer Self-Oscillators via Rheostat Feedback Mechanism.","authors":"Kai Li, Zuhao Li, Lin Zhou","doi":"10.3390/polym17050617","DOIUrl":"10.3390/polym17050617","url":null,"abstract":"<p><p>The reliance of feedback mechanisms in conventional light-fueled self-oscillating systems on spatially distributed light and intricately designed structures impedes their application and development in micro-robots, miniature actuators, and other small-scale devices. This paper presents a straightforward rheostat feedback mechanism to create an electrically driven liquid crystal elastomer (LCE) self-oscillator which comprises an LCE fiber, a rheostat, a spring, and a mass. Based on the electrothermally responsive LCE model, we first derive the governing equation for the system's dynamics and subsequently formulate the asymptotic equation. Numerical calculations reveal two motion phases, i.e., static and self-oscillating, and elucidate the mechanism behind self-oscillation. By employing the multi-scale method, we identify the Hopf bifurcation and establish the analytical solutions for amplitude and frequency. The influence of various system parameters on the amplitude and frequency of self-oscillation was analyzed, with numerical solutions being validated against analytical results to ensure consistency. The proposed rheostat feedback mechanism can be extended to cases with rheostats that have more general resistance properties and offers advantages such as simple design, adjustable dimensions, and rapid operation. The findings are expected to inspire broader design concepts for applications in soft robotics, sensors, and adaptive structures.</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":"17 5","pages":""},"PeriodicalIF":4.7,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11902770/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143616935","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":"Impacts of Rotor Design, Screw Design, and Processing Parameters in a Farrel Continuous Mixer.","authors":"Mansour Alotaibi, Carol Forance Barry","doi":"10.3390/polym17050619","DOIUrl":"10.3390/polym17050619","url":null,"abstract":"<p><p>Continuous mixers, which consist of a section with non-intermeshing counter-rotating rotors and a single-screw extruder, were developed for thermoset rubber and are often used for compounding of heavily filled thermoplastics. Due to the high mixing efficiency and tight control of shear levels, they may be suited for other compounding other material systems. Little work, however, has been reported on compounding with these mixers, and preliminary work with polypropylene showed interesting limitations of the mixing parameters. Therefore, this study investigated the effects of nine rotor designs, two single-screw designs, rotor speed, feed rate, and orifice setting on the residence time and melt temperature in a Farrel Compact Processor. In general, single-stage rotors produced lower mixer residence times and melt temperatures compared to longer two-stage and high dispersion rotors. Higher rotor speeds and feed rates and smaller orifice openings generally reduced mixer residence times. Higher rotor speeds increased mixer melt temperatures, whereas higher feed rates and smaller orifice openings produced lower mixer melt temperatures. The single-screw design impacted the residence time but not the melt temperature. Overall, the results of this work provided strategies for optimizing the processing parameters and rotor design selection when melt compounding with continuous mixers.</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":"17 5","pages":""},"PeriodicalIF":4.7,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11902392/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143616656","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 3D-Printing Model Resin with Low Volumetric Shrinkage and High Accuracy.","authors":"Long Ling, Theresa Lai, Pei-Ting Chung, Sara Sabet, Victoria Tran, Raj Malyala","doi":"10.3390/polym17050610","DOIUrl":"10.3390/polym17050610","url":null,"abstract":"<p><p>This study aims to assess and compare the shrinkage, accuracy, and accuracy stability of a novel 3D-printing model resin and eight commercially available 3D-printing model resin materials. The experimental model resin was developed by our 3D-printing proprietary resin technology. Eight commercially available 3D-printing model resins were included for comparison. The AcuVol video imaging technique was used to test volumetric shrinkage. Full-arch tooth models were printed for each model resin via digital light processing (DLP) technology. The 3D average distance between the scanned model and the designed CAD digital file was applied to determine the dimensional accuracy of the 3D-printed full-arch tooth models. One-way ANOVA and Tukey's post hoc test (<i>p</i> < 0.05) were utilized to analyze the average values of volumetric shrinkage and 3D average distance (dimensional accuracy). The experimental model resin showed significantly lower volumetric shrinkage (7.28%) and significantly higher or higher accuracy and accuracy stability (11.66-13.77 µm from the initial day to four weeks) than the other commercially available model resins (7.66-11.2%, 14.03-41.14 µm from the initial day to four weeks). A strong correlation was observed between volumetric shrinkage and dimensional accuracy (Pearson correlation coefficient R = 0.7485). For clinically successful modelling applications in restorations, orthodontics, implants, and so on, the new 3D-printing model resin is a promising option.</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":"17 5","pages":""},"PeriodicalIF":4.7,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11902753/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143616834","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 Structurally Modified Toluene Diisocyanate-Based Polyurethane Pads on Chemical Mechanical Polishing of 4H Silicon Carbide Substrate.","authors":"Yiming Meng, Shanduan Zhang, Zefang Zhang","doi":"10.3390/polym17050613","DOIUrl":"10.3390/polym17050613","url":null,"abstract":"<p><p>This study investigates the impact of polycarbonate diol (PCDL)-modified toluene diisocyanate (TDI)-based polyester polyurethane polishing pads on the chemical mechanical polishing of 4H silicon carbide (4H-SiC) substrates. Employing a unique metho, PCDL alters the ratio of polyurethane soft and hard segments, facilitating the one-step synthesis of a polishing pad via chemical foaming. The extent of the reaction of isocyanate groups was characterized by Fourier transform infrared spectroscopy, while the changes in the glass transition temperature of the material before and after modification were evaluated using differential scanning calorimetry. The mechanical properties and surface morphology of the modified pad have been systematically characterized. The results showed that compared with the polyurethane polishing pad without PCDL, tensile strength was augmented by a factor of 2.1, the elastic modulus surged by a factor of 4.2, the elongation at break improved by a factor 1.6, and the wear index decreased by a factor of 0.5 by 40 wt.% PCDL loading. Furthermore, the modified pad demonstrated a 14.5% increase in material removal rate and a reduction in surface roughness of 4H-SiC from 0.124 nm to 0.067 nm. Additionally, the compact surface pore structure and enhanced chemical stability in the strong oxidizing slurry of the modified pad enabled superior polishing performance, achieving an ultrasmooth 4H-SiC surface. The study highlights the potential of tailored polyurethane formulations in enhancing polishing efficiency and surface finish in semiconductor manufacturing processes.</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":"17 5","pages":""},"PeriodicalIF":4.7,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11902601/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143616919","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":"Rheological Properties of Polyethylene Color Masterbatches Containing Pigment RED 122 (2,9-Dimethylquinacridone) Modified by Silanes Using Pulverization Method.","authors":"Magdalena Kozłowska, Magdalena Lipińska, Michał Okraska","doi":"10.3390/polym17050618","DOIUrl":"10.3390/polym17050618","url":null,"abstract":"<p><p>Polyethylene color masterbatches containing pigment RED 122, 2,9-dimethylquinacridone, ((2,9-dimethyl-5,12-dihydroquinolino[2,3-b]acridine-7,14-dione) modified by the pulverization method in ball mills were obtained. As pigment-modifying agents, isobutyltrimethoxysilane IBTMS and octyltrietoxysilane OTES were used. The viscoelastic properties of the prepared masterbatches were investigated by using an oscillation rotational rheometer. The impact of the 2 wt.% of coloring masterbatch on the rheological behavior of polyethylene during processing at 170 °C was analyzed. Storage shear modulus G', loss shear modulus G″, complex viscosity η* and loss factor tan δ were analyzed. Modification prevents the agglomeration of modified pigment particles in the masterbatch, leading to a significant increase in the storage shear modulus G', from 13.83 kPa (masterbatch containing pigment RED 122) to 58.74 kPa (pigment modified with 2 wt.% of IBTMS) and 49.67 kPa (pigment modified with 2 wt.% of OTES). The analysis of the continuous relaxation models showed that the modified pigment influenced the relaxation of melted polyethylene. The tendency of the silane-modified pigment to create its \"own structure\" in the polyethylene carrier via particle-particle interactions was estimated based on rotational tests at low and high shear rates. The larger area of viscosity loops was determined at 170 °C for the masterbatch containing 1 wt.% of OTES-modified pigment, 2574.44 Pas(1/s), as compared with the reference masterbatch, 464.88 Pas(1/s). The Carreau and Carreau-Yasuda viscosity models were applied to analyze the flow curve and the changes in viscosity as a function of the shear rate. After pigment modification, the zero shear viscosity µ₀ of the mixtures of polyethylene/pigment masterbatch changed from 234.9 Pas (pigment RED 122) to 305.9 Pas (pigment modified with 1 wt.% of IBTMS). The influence of the modified pigments on the crystallization of polyethylene and its thermal stability was investigated. The temperatures of melting T_m were determined.</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":"17 5","pages":""},"PeriodicalIF":4.7,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11902374/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143616691","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":"Poly(Vinylpyrrolidone) Graft in Poly(Vinyl Chloride) Catheters Using Gamma Radiation for Ciprofloxacin Loading and Release.","authors":"Pedro J Vargas-Machado, Felipe López-Saucedo, Emilio Bucio","doi":"10.3390/polym17050612","DOIUrl":"10.3390/polym17050612","url":null,"abstract":"<p><p>This study addresses the modification of poly(vinyl chloride) catheters with <i>N</i>-vinylpyrrolidone and ciprofloxacin to achieve an antimicrobial surface. The copolymer was synthesized using the grafting-from method with gamma rays as a physical initiator and under different reaction conditions (absorbed dose, monomer concentration, and solvent). The modified catheters attained hydrophilic properties and were tested for ciprofloxacin loading and release efficiency. Antibiotic-loaded materials successfully inhibited the growth of <i>S. aureus</i> and <i>P. aeruginosa</i> strains. Therefore, surfaces with PVP chains exhibit suitable features for the loading and release of small molecules like ciprofloxacin (a fluoroquinolone). Results suggest that graft copolymers are suitable materials for the fabrication of biomedical devices with antibacterial features.</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":"17 5","pages":""},"PeriodicalIF":4.7,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11902714/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143616964","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":"Diamine-Crosslinked and Blended Polyimide Membranes: An Emerging Strategy in Enhancing H₂/CO₂ Separation.","authors":"Noor Hafizah Mohd Amin, Mohd Usman Mohd Junaidi, Zulhelmi Amir, Nur Awanis Hashim, Hanee Farzana Hizaddin, Abdul Latif Ahmad, Mohd Izzudin Izzat Zainal Abidin, Mohamad Fairus Rabuni, Sharifah Norsyahindah Syed Nor","doi":"10.3390/polym17050615","DOIUrl":"10.3390/polym17050615","url":null,"abstract":"<p><p>The increasing demand for high-purity hydrogen (H₂) as renewable energy sources is driving advancements in membrane technology, which is essential for achieving efficient gas separation. Polyimide (PI) membranes have become an emerging option for H₂/CO₂ separation due to its excellent thermal stability and stability under harsh conditions. However, the neat PI membrane suffers performance loss due to CO₂ plasticization effect and an encountered trade-off limit between permeability and selectivity. Therefore, membrane modification by crosslinking and blending emerged as a recent strategy to enhance the membrane's performance and properties. This paper provides: (1) An overview of the possible method to do the modification in PI membranes, including the advantages and challenges of the membrane modification types; (2) As blending and crosslinking is the most popular modification for the PI membrane, their roles in enhancing membrane properties for improved H₂/CO₂ separation are discussed; (3) The critical parameters of the blending and crosslinking processes are also clarified for the optimal purification process; (4) The future outlook for H₂/CO₂ separation using membrane technology is discussed, aiming to provide commercialization strategy for optimal H₂/CO₂ separation. Thus, this review could provide guidelines for the readers to implement changes that significantly enhance the membrane's features for high-purity H₂ production.</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":"17 5","pages":""},"PeriodicalIF":4.7,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11902560/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143616882","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":"Study of Polyhedral Oligomeric Silsesquioxane-Modified Superhydrophilic Transparent Coating in Antifogging, Antifrost and Self-Cleaning.","authors":"Weibiao Zhu, Chengfeng Wu, Jinxin He, Xia Dong","doi":"10.3390/polym17050599","DOIUrl":"10.3390/polym17050599","url":null,"abstract":"<p><p>A highly hydrophilic coating with a water contact angle below 10° was developed on a transparent polycarbonate (PC) sheet using a UV-curable process. Polyhedral oligomeric silsesquioxanes (POSS), modified with poly(ethylene glycol) methacrylate (PEGMA), provided the hydrophilic functionality essential for the coating. Fogging and frost formation on transparent surfaces often hinder visibility and pose challenges in various optical applications. The hydrophilic coating developed in this study demonstrated excellent antifogging and antifrost properties, along with a notable self-cleaning capability. These characteristics make it a promising candidate for applications in transparent optical PC materials, requiring enhanced antifogging, antifrost, and self-cleaning performance.</p>","PeriodicalId":20416,"journal":{"name":"Polymers","volume":"17 5","pages":""},"PeriodicalIF":4.7,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11902433/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143616812","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}