Polymeric Materials Research Articles

Toward a Sustainable Approach for Durably Hydrophilic and UV Protective PET Fabric through Surface Activation and Immobilization Integrating Epigallocatechin Gallate and Citric Acid.

Enhancing the hydrophilicity and UV protective property of poly(ethylene terephthalate) (PET) fabric are two significant ways to upgrade its quality and enlarge the applicable area. Biobased finishes are greatly welcomed for the fabrication of sustainable textiles; however, their application on PET fabric is still challenging compared with the case of natural fabric. This study presents a strategy that immobilizes epigallocatechin gallate (EGCG) onto PET fabric using citric acid (CA) for durably hydrophilic and UV-proof properties with negligible color change. A controllable surface-activating method integrating alkaline and deep eutectic solvent (DES) is customized for the PET fabric to promote the reactions among PET, CA, and EGCG. The hydrophilic, antistatic, and UV protective properties of functionalized PET fabric were explored. Results show that the hydrophilicity of the PET fabric after direct EGCG treatment increases but drops sharply after first-round washing due to weak interactions. The combined alkaline/DES pretreatment increases the number of hydrophilic groups and the roughness of PET fibers. After EGCG modification, the moisture regain (MR) of PET fabric increases from 0.41 to 0.64%. The contact angle and electrostatic charge half-life (T1/2) decreases from >120 to 23°, and from >60 to 0.13 s, respectively. The MR and T1/2 are well retained after a 10-cycle washing. In addition, the UV protective factor of the PET fabric increases from 18 to 36. A very slight yellowing phenomenon occurs on the PET fabric after the treatment. In all, this research attempts to integrate a biobased finishing agent and an eco-friendly cross-linker on synthetic fiber for durable functions, which is transferrable to the sustainable fabrication of other polymeric materials such as fibers or films.

Biodegradable Poly (L-Lactic acid) Fibrous Membrane with Ribbon-Structured Fibers and Ultrafine Nanofibers Enhances Air Filtration Performance.

Here, the poly (l-lactic acid) (PLLA) membrane with multi-structured networks (MSN) is successfully prepared by electrospinning technology for the first time. It is composed of micron-sized ribbon-structured fibers and ultrafine nanofibers with a diameter of tens of nanometers, and they are connected to form the new network structure. Thanks to the special fiber morphology and structure, the interception and electrostatic adsorption ability for against atmospheric particulate matter (PM) are significantly enhanced, and the resistance to airflow is reduced due to the "slip effect" caused by ultrafine nanofibers. The PLLA MSN membrane shows excellent filtration performance with ultra-high filtration efficiency (>99.9% for PM2.5 and >99.5% for PM0.3) and ultra-low pressure drop (≈20Pa). It has demonstrated filtration performance that even exceeds current non-biodegradable polymer materials, laying the foundation for future applications of biodegradable PLLA in the field of air filtration. In addition, this new structure also provides a new idea for optimizing the performance of other polymer materials.

Liquid-liquid phase separation induced by crowding condition affects amyloid-β aggregation mechanism.

Liquid-liquid phase separation (LLPS) is common in the aggregation of proteins associated with neurodegenerative diseases. Many efforts have been made to reproduce crowded conditions with artificial polymeric materials to understand the effect of LLPS in physiological conditions with significantly highly concentrated proteins, such as intrinsically disordered proteins. Although the possibility that LLPS is involved in intracellular amyloid-β (Aβ) aggregation, a protein related to the pathogenesis of Alzheimer's disease, has been investigated, the relationship between LLPS and the aggregation of Aβ is poorly characterized. Thus, in this study, we mimicked the intracellular crowding environment using polyethylene glycol and dextran, used commonly as model polymers, to examine the relationship of Aβ with LLPS and aggregation dynamics in vitro. We confirmed that Aβ undergoes LLPS under specific polymer coexistence conditions. Moreover, the addition of different electrolytes modulated LLPS and fibril formation. These results suggest that hydrophobic and electrostatic interactions are the driving forces for the LLPS of Aβ. Similar to the role of the liposome interface, the interface of droplets induced by LLPS functioned as the site for heterogeneous nucleation. These findings offer valuable insights into the complex mechanisms of Aβ aggregation in vivo and may be useful in establishing therapeutic methods for Alzheimer's disease.

Characterization of reinforcing polymeric material with recycled sugarcane bagasse wastes as fiber natural reinforcement

Characterization of reinforcing polymeric material with recycled sugarcane bagasse wastes as fiber natural reinforcement

The Influence of Three-Dimensionally Printed Polymer Materials as Trusses and Shell Structures on the Mechanical Properties and Load-Bearing Capacity of Reinforced Concrete

The Influence of Three-Dimensionally Printed Polymer Materials as Trusses and Shell Structures on the Mechanical Properties and Load-Bearing Capacity of Reinforced Concrete

Fire and Heat Retardant Polymer Materials and Coatings with Functionally Active Phosphorus–Boron–Nitrogen-Containing Components

Fire and Heat Retardant Polymer Materials and Coatings with Functionally Active Phosphorus–Boron–Nitrogen-Containing Components

A survey of recent publications on polymers employing reactive, halogen‐free flame‐retardant functionalities

AbstractModern society relies heavily on producing commercial and industrial plastics to improve the quality and quantity of our lives. However, increased fire risks threaten commercial operations and the potential impact of high‐performance electronic and transportation technologies that utilize polymeric materials. Despite significant monitoring and reduction of commonly used halogenated flame retardants, their worldwide usage still poses environmental hazards. Many non‐halogenated flame‐retardant compounds are viable additives for synthetic polymers; however, their incorporation often results in reduced composite homogeneity and mechanical strength. This review focuses on reactive flame retardants and the effect of polymer structure on inherent flame retardance in recent studies. The synthesis and characterization of polymeric systems (e.g. polyurethanes, polyamides, polyimides, polyesters and epoxy resins) are discussed in terms of structure–flame‐retardant performance using a complement of analytical tools, including thermogravimetric analysis, cone calorimetry, limiting oxygen index and UL 94 testing. These commercially important polymeric systems represent a broad compositional space for future adaptation and the discovery of increasingly modular polymeric materials with, while also contributing to the fundamental understanding of unique combinations of gas‐ and condensed‐phase mechanisms of flame retardance. © 2024 Society of Chemical Industry.

Cationic Imidazolium-Urethane-Based Poly(Ionic Liquids) Membranes for Enhanced CO2/CH4 Separation: Synthesis, Characterization, and Performance Evaluation

The escalating emissions of CO2 into the atmosphere require the urgent development of technologies aimed at mitigating environmental impacts. Among these, aqueous amine solutions and polymeric membranes, such as cellulose acetate and polyimide are commercial technologies requiring improvement or substitution to enhance the economic and energetic efficiency of CO2 separation processes. Ionic liquids and poly(ionic liquids) (PILs) are candidates to replace conventional CO2 separation technologies. PILs are a class of materials capable of combining the favorable gas affinity exhibited by ionic liquids (ILs) with the processability inherent in polymeric materials. In this context, the synthesis of the IL GLYMIM[Cl] was performed, followed by ion exchange processes to achieve GLYMIM variants with diverse counter anions (NTf2−, PF6−, and BF4). Subsequently, PIL membranes were fabricated from these tailored ILs and subjected to characterization, employing techniques such as SEC, FTIR, DSC, TGA, DMA, FEG-SEM, and CO2 sorption analysis using the pressure decay method. Furthermore, permeability and ideal selectivity assessments of CO2/CH4 mixture were performed to derive the diffusion and solubility coefficients for both CO2 and CH4. PIL membranes exhibited adequate thermal and mechanical properties. The PIL-BF4 demonstrated CO2 sorption capacities of 33.5 mg CO2/g at 1 bar and 104.8 mg CO2/g at 10 bar. Furthermore, the PIL-BF4 membrane exhibited permeability and ideal (CO2/CH4) selectivity values of 41 barrer and 44, respectively, surpassing those of a commercial cellulose acetate membrane as reported in the existing literature. This study underscores the potential of PIL-based membranes as promising candidates for enhanced CO2 capture technologies.

Predicting bond line thickness of polymeric thermal interface materials based on the rheological properties

Bond line thickness (BLT) is an essential parameter of thermal conductive composite gels as the thermal interface material (TIM). Extensive research has been performed on designing next-generation TIMs with high thermal conductivity; however, it remains elusive how to link laboratory measurements and the theoretically predicted BLT. Here, we propose a new model to estimate BLT based on a rheological property, in which the TIM is assumed to be a simple power law fluid. To avoid the unrealistic situation of the BLT tending to zero, we introduce a decaying exponential function to describe the influence from fillers during the lid attach process and rebuild the force balance equation. Compared with previously reported models, the theoretical prediction BLT based on the proposed model is in good agreement with the experimental data. Our model has a guiding significance in predicting the BLT, which may help to optimize the thermal performance of TIMs.

The Thermal Energy Storage Characteristics of Oleic Acid Modified ZnO‐Decorated Polymer Matrix‐Supported Composite Phase Change Materials: Synthesis and Characterization

AbstractIn this study, modified nano zinc oxide (ZnO)‐reinforced polymer‐supported novel thermally enhanced form‐stable composite phase change materials (PCMs) are presented, which are prepared via water in oil emulsion polymerization and following impregnation process steps. First, ZnO nanoparticles are modified with oleic acid (OA) to obtain lipophilic structures for emulsion stability, which are designed to take a role as a heat transfer activator. To ensure the shape stabilization of n‐hexadecane used as organic PCM, polymeric support materials are synthesized in the presence of modified ZnO nanoparticles (ZnO@OA). The polymeric frameworks exhibit open porous morphology, and the thermal stability of the support matrix improves with the addition of ZnO nanofiller. In the second step, composite PCMs are prepared by incorporation of n‐hexadecane with the solvent‐assisted vacuum impregnation method into polymer composites. The 1.0% ZnO@OA incorporated composite PCM has the highest incorporation ratio and exhibits a thermal storage capability (η) of 100%. According to the T‐history and thermal conductivity tests, it is observed that the heat conduction rate is enhanced with the addition of ZnO@OA nanofiller. The conclusion is that the obtained ZnO@OA integrated composite PCMs have a remarkable potential for latent heat storage applications requiring low temperature in the range of 5–25 °C.

Advancing earthquake resistance: Hybrid retrofitting of RC frames with FRP and TDS

Traditional and technological retrofitting methods have been proposed over time to enhance earthquake resistance in structures. Friction-type dampers have attracted considerable interest from both researchers and the construction industry because of their versatility in retrofitting, quick installation, and non-destructive characteristics. Moreover, the integration of damping systems with various retrofitting elements and the resulting impact of these hybrid systems on building performance have consistently been subjects of interest. This study involved the construction of three identical half-scale reinforced concrete (R.C) frames. One frame served as the reference (REF), the second was wrapped with Fiber Reinforced Polymers (FRP) material (REF-FRP), and the third was retrofitted using both FRP wrapping and the developed Technological Damper System (TDS-FRP). Quasi-static cyclic experiments were performed on the three structural frames, providing force-displacement and force-rotation relationships. The acquired data were then used to assess the damage states of the frames according to the Turkish Building Earthquake Code (TBEC 2018), and energy consumption rates were determined. Moreover, Finite Element Method (FEM) analyses were performed on REF, REF-FRP, and TDS FRP frames to derive force-displacement relationships, which were subsequently compared with experimental findings. The experiment results indicate that the horizontal load-carrying capacity of the TDS-FRP frame increased by 76 % to 122 % compared to the REF frame, while the REF-FRP frame showed a maximum increase of 14 %. Additionally, the cumulative energy consumption capacity of the REF-FRP frame increased by a maximum of 42 % compared to the REF frame, and the TDS-FRP increased between 51 % and 156 %. At a 1 % drift ratio, shear cracks at the beam ends and column-beam intersections of the REF frame were observed to be significantly reduced in the REF-FRP frame and eliminated in the TDS-FRP frame. Additionally, upon reaching a 3 % drift ratio, it was observed that the TDS-FRP frame remained within acceptable limits as per TBEC 2018, whereas the REF and REF-FRP frames exceeded the advanced damage limit. Additionally, it has been observed that the results obtained from FEM analyses coincide with the experimental results. In this context, the TDS-FRP hybrid application can be considered as an effective and alternative solution for the R.C buildings.

Poisson’s Ratio Prediction of Injection Molded Thermoplastics Using Differential Scanning Calorimetry

In the development of thermoplastic products, it is necessary to conduct the necessary mechanical tests and evaluate the reliability of thermoplastics in each case, because the mechanical properties of the same material vary depending on the molding process conditions and product shape. In order to build a sustainable society, it is expected that the evaluation of the mechanical properties of thermoplastics, which are resource and energy saving, will be required. In this paper, the glass transition temperature and melting point of injection-molded thermoplastics were evaluated by differential scanning calorimetry, and the correlation between Poisson’s ratio and free volume was obtained by applying the theory proposed by Flory et al. A certain correlation was found between the Poisson’s ratio of polymers and the change in free volume determined by the glass transition temperature. It is also clear that this relationship can be approximated by orders of magnitude. The Poisson’s ratio of the core layer tended to be smaller than that of the skin layer. It has also been found that there is a negative correlation between the Young’s modulus and the free volume of the polymer material.

Possibility assessment for using protective coatings and polymer materials on tubing to prevent inorganic scaling on the inner surface of pipes

AbstractThe inorganic scaling in wells is a common problem faced by mining companies. At present, the use of protective coatings for tubing as a measure to prevent or reduce the formation of inorganic scale deposits on pipe walls has not been fully studied. To use protective coatings as a measure to counteract the deposition of inorganic salts, it is necessary to develop a method that allows assessing the ability of coatings, as well as polymer and metal materials, to prevent the formation of inorganic scale deposits on the inner surface of pipes.The article proposes a method for assessing the ability of protective coatings to resist the inorganic scaling on the inner surface of tubing. The proposed assessment method allows to make an informed decision on the advisability of using internal protective coatings of tubing to prevent (or reduce) the formation of inorganic scale deposits. The authors consider design features of a test bench for assessing the resistance of coatings to inorganic scale deposits, which allows to simulate the conditions for the formation of scale deposits that are as close as possible to the real conditions of oil production facilities. The article presents the results of bench tests of nine coating samples, two polymer samples and one sample made of St 40G2 steel. To assess the effectiveness of using tubing with an internal anti-corrosion coating as a measure to combat scale deposits, additional research is required to assess the possibility of complex use of coatings in conjunction with other methods of preventing processes of inorganic scaling. Thus, the authors developed the Bench for assessing the resistance of protective coatings of tubing to inorganic scale deposits. A dynamic testing technique is proposed to evaluate the resistance of protective coatings to inorganic scale deposits. Based on the presented results, conclusions were drawn about the possibility of using protective coatings on tubing as a measure to prevent the formation of inorganic scale deposits on the inner surface of the tubing.

Low Volume Gas-Flow Seeding For Highly Resolved Velocimetry Of The Boundary Layer

Ensuring fire safety in polymeric materials, which are inherently flammable but widely used in various industries, is of significant societal and economic importance. This study is part of a broader effort to understand polymer combustion and flame retardant effectiveness at a fundamental level. A major focus is the behavior of polymers burning along a vertical wall, a configuration chosen to study the release of flammable gases during pyrolysis, which contributes to the self-sustaining combustion reaction of a fire. This process occurs predominantly near the polymer surface within the boundary layer, requiring detailed analysis to evaluate flame retardant effectiveness. Our experimental setup replicates polymer pyrolysis using a flame-wall interaction burner with a vertical jet and a small inlet to mimic the release of flammable gases. The primary challenge in this setup is the introduction of seeding particles for Particle Image Velocimetry (PIV) measurements at low volume flow rates, which is complicated by reflections from the wall and the small flow scale relative to the main flow. To address this problem, we have developed a novel piezo-based ultrasonic seeder capable of controlled seeding at extremely low flow rates, thereby improving the accuracy of PIV measurements in non-reactive configurations. This seeder uses a piezo ring to excite a perforated metal membrane, forming uniform aerosol droplets. The design ensures a steady supply of particles, which is critical for evaluating boundary layer conditions. Our results demonstrate the seeder’s ability to maintain sufficient seeding density in the low volume flow region, facilitating detailed velocimetry analysis. The innovative seeder design proves effective in overcoming the limitations of conventional methods and provides new insights into polymer combustion processes and the role of flame retardants.

Polydopamine-primed FeCo-LDH endowed epoxy resin with enhanced flame retardancy and mechanical properties

The integration of layered double metal hydroxides (LDH) into epoxy resin (EP) for flame retardancy is in line with the principles of environmentally friendly and sustainable development. In this study, polydopamine (PDA)-primed intercalated LDH containing iron and cobalt ions (LDH-DBS@PDA) was prepared, and its chemical composition, structure and morphology were thoroughly characterized. Due to the synergistic flame-retardant properties exhibited by LDH and PDA, as well as the catalytic charring properties of iron and cobalt ions in both condensed and gaseous phases, EP composite with 5 wt% LDH-DBS@PDA achieved a UL-94 V-0 rating with a limiting oxygen index of 30.7 %. Moreover, EP/LDH-DBS@PDA exhibited a significant decrease in total heat release by 48 % and smoke release by 52 %, demonstrating remarkable fire safety performance. Additionally, the existence of LDH-DBS@PDA improved impact strength, tensile strength, and glass transition temperature due to strong interactions between PDA and EP matrix. This work presents a promising strategy for developing highly efficiency flame retardants with excellent compatibility for polymeric materials.

Flexible Physical Unclonable Functions Based on Non-deterministically Distributed Dye-Doped Fibers and Droplets.

The development of new anticounterfeiting solutions is a constant challenge and involves several research fields. Much interest is currently devoted to systems that are impossible to clone, based on the physical unclonable function (PUF) paradigm. In this work, a new strategy based on electrospinning and electrospraying of dye-doped polymeric materials is presented for the manufacturing of flexible free-standing films that embed simultaneously different PUF keys. The proposed films can be used to fabricate novel anticounterfeiting labels having three encryption levels: (i) a map of fluorescent polymer droplets, with random positions on a dense yarn of polymer nanofibers, (ii) a characteristic fluorescence spectrum for each label, and (iii) the unique speckle patterns that every label produces when illuminated with coherent laser light shaped in different wavefronts. The intrinsic uniqueness introduced by the manufacturing process encodes enough complexity into the optical anticounterfeiting tag to generate thousands of cryptographic keys. The simple and cheap fabrication process as well as multilevel authentication makes such colored polymeric unclonable tags a practical solution in the secure protection of goods in our daily life.

Application Analysis of Biodegradable Polymer Materials in Food Packaging

With the rapid development of biotechnology, the society pays more attention than in the past to the production and development of environmental protection. Choosing materials has always been a more important part of environmental protection work, among them, the degradable polymer materials are also professional research topics, it can be self-degradation under certain conditions, with far-reaching environmental protection value and social significance. Food packaging is a kind of carrier that plays a protective role in packaging, preservation and sales of food, the application of degradable polymer materials in food packaging can play a positive role in environmental protection, reducing environmental pollution and building an ecological society. In this paper, the active application of biodegradable polymer materials for food packaging is elaborated, hoping to provide theoretical reference.

Closed-form solutions for FPR-to-concrete bonded joints with loaded-end anchorage: Insight into the interfacial shear transferring mechanism

Incorporation of end anchorage has not only proven to be an effective method for enhancing the low utilization rate of the expensive fiber-reinforced polymer (FRP) material in the application of flexural strengthening of reinforced concrete (RC) beams but also improving the poor ductility and low load-bearing capacity of the FRP-to-concrete interface. The shear transfer mechanism at the interface with free-end anchorage has been understood, but for the interface with loaded-end anchorage, the shear transfer mechanism remains unclear. In this paper, a new analytical model is present to elucidate the shear transfer mechanism of the FRP-to-concrete bonded joint with loaded-end anchorage, including the U-jacket, FRP anchor, and mechanical fastener. The analytical solutions are presented and compared with the finite element analysis (FEA) results, and the good agreement between them verifies the accuracy of the proposed model. A comparison of the load-slip curves is conducted for the FRP-to-concrete bonded joint under various conditions, including scenarios without any anchorage, with free-end anchorage, and with loaded-end anchorage. Finally, design strategies are put forth for multiple anchorages to improve the load-bearing capacity and ductility of the FRP-to-concrete interface.

Smart laser Sintering: Deep Learning-Powered powder bed fusion 3D printing in precision medicine

Medicines remain ineffective for over 50% of patients due to conventional mass production methods with fixed drug dosages. Three-dimensional (3D) printing, specifically selective laser sintering (SLS), offers a potential solution to this challenge, allowing the manufacturing of small, personalized batches of medication. Despite its simplicity and suitability for upscaling to large-scale production, SLS was not designed for pharmaceutical manufacturing and necessitates a time-consuming, trial-and-error adaptation process. In response, this study introduces a deep learning model trained on a variety of features to identify the best feature set to represent drugs and polymeric materials for the prediction of the printability of drug-loaded formulations using SLS. The proposed model demonstrates success by achieving 90% accuracy in predicting printability. Furthermore, explainability analysis unveils materials that facilitate SLS printability, offering invaluable insights for scientists to optimize SLS formulations, which can be expanded to other disciplines. This represents the first study in the field to develop an interpretable, uncertainty-optimized deep learning model for predicting the printability of drug-loaded formulations. This paves the way for accelerating formulation development, propelling us into a future of personalized medicine with unprecedented manufacturing precision.

First evidence of plastics in coypu (Myocastor coypus)'s platforms.

Platforms are structures built by coypus for various purposes, such as reproduction, resting, and thermoregulation. In a coastal wetland of central Italy, during a study aimed at investigating the characteristics of coypu's platforms, it was recorded, for the first time worldwide, the presence of plastic in these structures. Through a transect survey, we censused 83 platforms, among which three (3.61%) were found with presence of macro- and megaplastics (polystyrene, polypropylene, and low-density polyethylene in film form; polyester, polyamide, and expanded polystyrene in fragments). Through the FTIR spectra, it was possible to highlight the degradation of the polymeric materials. To stimulate possible in-depth investigations at the level of the food chain (e.g., coypu predators, including canids) in wet habitats, we discussed possible causes and implications of plastic presence in coypus' nest structures.