Polymeric Materials Research Articles

Novel DNA-Binding Activity Exhibited by Poly(aspartic acid) Hydrolase-1 Inhibits Poly(aspartic acid) Hydrolase Activity.

Significant attention has been shifted toward the use and development of biodegradable polymeric materials to mitigate environmental accumulation and potential health impacts. One such material, poly(aspartic acid) (PAA), is a biodegradable alternative to superabsorbent poly(carboxylates), like poly(acrylate). Three enzymes are known to hydrolyze PAA: PahZ1KT-1 and PahZ2KT-1 from Sphingomonas sp. KT-1 and PahZ1KP-2 from Pedobacter sp. KP-2. We previously reported the X-ray crystal structure for PahZ1KT-1, which revealed a homodimer complex with a strongly cationic surface spanning one side of each monomer. Here, we report the first characterization of any polymer hydrolase binding to DNA, where modeling data predict binding of the polyanionic DNA near the cationic substrate binding surface. Our data reveal that PahZ1 homologues from Sphingomonas sp. KT-1 and Pedobacter sp. KP-2 bind ssDNA and dsDNA with nanomolar binding affinities. PahZ1KT-1 binds ssDNA and dsDNA with an apparent dissociation constant, KD,app = 81 ± 14 and 19 ± 1 nM, respectively, and these estimates are similar to the same behaviors exhibited by PahZ1KP-2. Gel permeation chromatography data reveal that dsDNA binding promotes inhibition of PahZ1-catalyzed PAA biodegradation for each homologue. We propose a working model wherein binding of PahZ1 to extracellular biofilm DNA aids in the localization of the hydrolase to the environment in which PAA would first be encountered, thereby providing a mechanism to degrade extracellular PAA and potentially harvest aspartic acid for nutritional uptake.

Ultimate resistance and fatigue performance predictions of woven-based fiber reinforced polymers using a computational homogenization method

PurposeIn order to achieve the desired macroscopic mechanical properties of woven fiber reinforced polymer (FRP) materials, it is necessary to conduct a detailed analysis of their microscopic load-bearing capacity.Design/methodology/approachUtilizing the representative volume element (RVE) model, this study delves into how the material composition influences mechanical parameters and failure processes.FindingsTo study the ultimate strength of the materials, this study considers the damage situation in various parts and analyzes the stress-strain curves under uniaxial and multiaxial loading conditions. Furthermore, the study investigates the degradation of macroscopic mechanical properties of fiber and resin layers due to fatigue induced performance degradation. Additionally, the research explores the impact of fatigue damage on key material properties such as the elastic modulus, shear modulus and Poisson's ratio.Originality/valueBy studying the load-bearing mechanisms at different scales, a direct correlation is established between the macroscopic mechanical behavior of the material and the microstructure of woven FRP materials. This comprehensive analysis ultimately elucidates the material's mechanical response under conditions of fatigue damage.

Experimental design of polymer synthesis applied to the removal of Cd2+ ions from water via adsorption

Cadmium is a highly toxic metal, and its presence can have adverse effects on both human health and aquatic ecosystems. The efficient removal of cadmium from wastewater is therefore of crucial importance, but traditional methods have proved to be inadequate. Thus, technologies for the treatment of wastewater containing cadmium, including adsorption, have been developed. The aim of this study was the preparation of a polymeric material by the grafting reaction of κ-carrageenan and its use as an adsorbent for cadmium removal. This was performed to study the removal capacity of cadmium ions in synthetic solutions, as well as the effects of pH and ions on adsorption capacity, adsorption kinetics, isotherms, and reusability. Additionally, the disinfectant potential of the solution was evaluated for the inactivation of total coliforms and E. coli in river water. The best adsorption capacity was 75.52 ± 1.325 mg g−1, with the kinetics described by the pseudo-second order model. Maximum adsorption capacity (127.6 ± 1.833 mg g−1) and RL (0.0113) were determined using the Langmuir model, the Freundlich model was the one that best fits the experimental data and indicated cooperative adsorption, and the Dubinin-Radushkevich isotherm was used to obtain the adsorption energy and identify that it is physical. The presence of ions K+, Na+, Mg2+, and Ca2+ in a concentration of 0.5% decreased the adsorption capacity, and that at pH 2.0, the adsorption capacity was drastically reduced. The study indicates that the polymer has potential as an adsorbent for removing cadmium from aqueous solutions and exhibits self-disinfecting properties.

Bamboo fiber improves piglet growth performance by regulating the microbial composition of lactating sows and their offspring piglets

IntroductionFeeding bamboo powder is a kind of fiber raw material mainly composed of insoluble dietary fiber (IDF). In this study, IDF-based rice husk meal and feeding bamboo powder were used to compare the effects of bamboo fiber on fecal microflora and the performance of lactating sows and their offspring piglets.MethodsThirty healthy crossbred gilts (Yorkshire × Landrace) at day 105 of gestation were randomly allocated into three groups: CON, TRE1 supplemented with 2% BBF1 (feeding bamboo powder), and TRE2 supplemented with 2% BBF2 (99% feeding bamboo powder +1% bamboo fiber polymer material). The reproductive performance, serum indexes, and fecal microbiota of sows and piglets were analyzed. The results showed that, compared with CON, the average feed intake of sows in TRE1 during the second week of lactation was significantly increased by 21.96% (p < 0.05), the average daily gain (ADG) per litter in TRE1 on 11–21 days and 3–21 days of lactation was significantly increased by 50.68 and 31.61%, respectively (p < 0.05), and the serum triglyceride content of sows in TRE1 on the 21st day of lactation was significantly increased (p < 0.05). The 16S rRNA analysis showed that dietary bamboo fiber significantly increased the fecal microbial richness index Ace, Chao, and Sobs of sows (p < 0.05) and tended to increase the Sobs index of suckling piglets on day 21 (p < 0.10). Compared with CON, BBF1 supplementation significantly decreased the abundance of Christensenellaceae_R-7_group in feces of sows on days 7 and 21 after delivery (p < 0.05), while BBF2 decreased the genera Christensenellaceae_R-7_group on days 7 (p < 0.10) and 21 (p < 0.05) after delivery. Spearman correlation analysis showed that the abundance of Phascolarctobacterium in the feces of piglets on the 21st day after delivery was significantly positively correlated with diarrhea rate and significantly negatively correlated with ADG per litter, day 21 litter weight, and 3- to 21-day survival rate. In contrast, Christensenellaceae_R-7_group was significantly negatively correlated with diarrhea rate and positively correlated with ADG per litter.DiscussionThese results indicated that maternal BBF1 supplementation improved the litter weight gain of suckling piglets, which was associated with the improvement of diversity and structure of the fecal microbiota in the piglets.

Antibacterial Food Packaging Containing Stably Dispersed Cu Nanoparticles Synthesized by Novel Physical Vapor Deposition Process

Polymeric materials were modified by nanoparticles on powder (NPP) facility in which metal nanoparticles (Cu, Cu/Zn alloy etc.) are formed on the surface of rotating carrier powder by using physical vapor deposition process untile the metal content reached 0.3wt.%. The polymer material with metal nanoparticles deposited on their surface through the NPP process was then added to the raw polymer material at a ratio of 1 to 9. The mixture of modified polymer powder and raw polymer powder were then processd into a film by conventional processes such as hot melting, extrusion, T-die, and antibacterial characteristics of the film were investigated. We ultimately manufactured antibacterial food package using the film and conducted preservation test for two weeks at room temperature. Since food package containing 0.03wt.% Cu nanoparticles showed over 99.9% bacteria reduction rate, it slowed down the progress of deterioration significantly compared to conventional packages. For safety evaluation, the amount of copper released out was analyzed and a cytotoxicity test was also conducted.

Monoolein-Based Wireless Capacitive Sensor for Probing Skin Hydration

Capacitive humidity sensors typically consist of interdigitated electrodes coated with a dielectric layer sensitive to varying relative humidity levels. Previous studies have investigated different polymeric materials that exhibit changes in conductivity in response to water vapor to design capacitive humidity sensors. However, lipid films like monoolein have not yet been integrated with humidity sensors, nor has the potential use of capacitive sensors for skin hydration measurements been fully explored. This study explores the application of monoolein-coated wireless capacitive sensors for assessing relative humidity and skin hydration, utilizing the sensitive dielectric properties of the monoolein–water system. This sensitivity hinges on the water absorption and release from the surrounding environment. Tested across various humidity levels and temperatures, these novel double functional sensors feature interdigitated electrodes covered with monoolein and show promising potential for wireless detection of skin hydration. The water uptake and rheological behavior of monoolein in response to humidity were evaluated using a quartz crystal microbalance with dissipation monitoring. The findings from these experiments suggest that the capacitance of the system is primarily influenced by the amount of water in the monoolein system, with the lyotropic or physical state of monoolein playing a secondary role. A proof-of-principle demonstration compared the sensor’s performance under varying conditions to that of other commercially available skin hydration meters, affirming its effectiveness, reliability, and commercial viability.

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.

Soy‐based polyester: Sustainable solutions for emerging materials

AbstractInnovative and renewable polymers and additives are the focus of increased research due to public and environmental pressure. There has been a recent uptick in interest from scientists in biobased “green” plasticizers that can be covalently bonded to replace harmful and migratory phthalate‐based plasticizers. Vegetable oils (VOs) are one of the biosources, as they are both plentiful and sustainable. This review aims to highlight the synthesis methods for soy‐based polyesters. Therefore, the chemistry of soybean oil as a polymeric material and its role in the synthesis of polyesters derived from soybeans are the primary topics of this review. This review covers the many ways in which soybean oil and its derivatives can be used to synthesize polyester, either directly or indirectly.Highlights The need for sustainable polymers is explored. Soybean oil‐based polyesters are covered. Modification and chemistry to convert soybean oil into polyester are described. Applications of soybean‐based polyesters are provided.

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.

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

Three-dimensional printing technology (3D printing) is becoming a more and more popular technology for aerospace, biology, medicine, mechanics, civil and other engineering fields. In civil engineering, researchers and engineers attempt to print construction materials such as concrete using 3D-printing technology. This study aims to investigate the reinforcement of concrete beams with 3D printing. To achieve this, fused deposition modeling (FDM) technology as a printing method and polylactic acid (PLA) as a material were selected. Two types of geometries were chosen to find the optimal mechanical behavior of concrete: high-performance concrete (HPC) reinforced with four types of trusses (Pratt, Howe, Warren, and Warren with vertical) and ultra-high-performance concrete (UHPC) reinforced with a hyperboloid shell structure. The compressive and tensile strengths of reinforced UHPC were examined by a three-point bending test, and reinforced HPC was examined by a four-point bending test. The results of the experiments show that hyperboloid shell structures can absorb energy, although the strength of reinforced UHPC is reduced. For example, there was a decrease of over 20% in the compressive strength and 41% in the flexural strength, but the ductility was raised. Adding the hyperboloid shell structure improved the deformability of the UHPC. When Warren and Howe trusses were added to the HPC as reinforcements, the flexural strength improved by over 26% and 4.3%, respectively. The overall results of this study show that the concrete reinforced with 3D-printed trusses was better than that with a hyperboloid shell structure.

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

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.

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.

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.