Polymer Bulletin最新文献

Polyurethane possesses excellent characteristics of high elasticity and high strength, making them very important for many applications, but developing high-performance polyurethanes with new properties to meet the needs of different fields remains a challenge. In this work, we developed a polyurethane with self-healing properties by introducing the dynamic Schiff bond into the backbone of polyurethane. In addition, the self-healing polyurethane was endowed with AIE molecule by condensation reaction. The increase in polyurethane hard segments significantly enhanced their mechanical strength, meanwhile, the prepared polyurethane film showed excellent self-healing properties with a self-healing efficiency of 70%. Upon incorporating AIE molecules into the polyurethane backbone, the resulting film exhibited pronounced yellow-green fluorescence under illumination. The PU solution as a fluorescent ink was used to print the pattern on the surface of polypropylene nonwoven fabric via screen printing. This offers a potential approach for achieving surface patterning on textiles using fluorescent self-healing polyurethane inks.

Graphical abstract

In this research, heat treated and silane functionalized horsetail derived biosilica was incorporated into a polydroxyalkanoate (PHA) matrix to fabricate environmentally sustainable bio composites through fused filament fabrication (FFF) 3D printing. Surface modification enhanced the interfacial compatibility between biosilica and PHA resulting in improved structural reinforcement and load transfer. Among the developed composites, MB2 (2 vol% biosilica) exhibited the highest mechanical properties which includes 53.9 MPa in tensile, 83.4 MPa in flexural, 3.05 J in impact and 78 Shore D hardness, as uniform filler dispersion and strong polymer filler bonding enabled efficient stress distribution. Additionally, tribological evaluation revealed that the composite with 4 vol% biosilica (MP3) provided the best wear resistance achieving the lowest specific wear rate (0.013 mm³/Nm) and the lowest coefficient of friction (0.31) attributed to the improved load bearing capacity during sliding. Moreover, MB3 also demonstrated superior flame retardancy (12 mm/min) due to the development of a compact silica rich char layer that effectively inhibited heat and oxygen diffusion. These findings confirm the potential of surface modified biosilica reinforced PHA composites as high performance, biodegradable engineering materials.

Polysaccharide derivatives, either in soluble or cross-linked form, are receiving growing attention for applications in the wastewater purification field, as they may satisfy some requirements of this activity domain in terms of environmental friendliness and costs. In this respect, this study was focused on determining the feasibility of pullulan microspheres (ms) functionalized with primary and tertiary amine groups as flocculants for removing two fungicide formulations (Melody Compact 49 WG (MC) and Cabrio^® Top (CT)) from simulated wastewater. The cationic ms were prepared by suspension cross-linking of pullulan and a subsequent coupling reaction of the amine to the hydroxyl groups of the polysaccharide. The physicochemical characterization of the ms was performed using scanning electron microscopy and infrared spectroscopy, and the degree of cationization was determined by the titration method. The effects of ms dose, degree of cross-linking and cationization, amine basicity, contact time, and fungicide dispersion characteristics—including initial pH, concentration, and salinity—on ms separation performance were evaluated. The results showed good removal efficiency (RE%) for both ms types with the two fungicide formulations in aqueous dispersions (RE% of 96% for MC and 83–89% for CT). Microspheres with higher basicity demonstrated greater efficacy in removing fungicides than those with lower basicity, achieving three times lower doses of ms and reducing removal time from 24 to 48 h to 6–8 h. Additionally, different flocculation mechanisms were identified. RE% values decreased slightly (up to 4–6%) for salted fungicide suspensions, and the best removal percentages were observed in water at a pH of 6.5. The data shown above highlight the good efficacy of cationized ms pullulan for removing complex fungicide formulations from suspensions with different characteristics, which recommend them for application in real wastewater, where fluctuations in environmental parameters (pH, salts, contaminant concentration) may occur.

Over the past few decades, the incidence of chronic wound diseases has risen dramatically, significantly impairing the quality of life for diabetic patients. The development of advanced wound care products is essential to prevent amputations and reduce mortality rates. This study focuses on the electrospinning of polylactic acid (PLA), gelatin, glycine, and PAMAM (polyamidamine) dendrimer composites with Melissa officinalis extract, specifically for diabetic wound healing applications. Notably, we have for the first time incorporated PAMAM G4.0 with Melissa officinalis extract as an antibacterial and anti-inflammatory agent, investigating the impact of piezoelectric properties on the release behavior of the active ingredient. Our findings reveal a direct correlation between the piezoelectric characteristics of the nanofibers and the drug release response of PAMAM, achieving a maximum drug release of 99.5% over 180 h. Crystallographic analysis confirmed the formation of the β-crystalline phase of PLA and glycine during electrospinning, followed by heat treatment. Piezoelectric characterization yielded maximum output current and voltage readings of 22.44 nA and 9.82 mV, respectively. The fabricated nanofibers exhibited promising wound dressing properties, including a fluid absorption rate of 512.3% and a water vapor transmission rate (WVTR) of 2067 g·m⁻²·day⁻¹. Importantly, the integration of Melissa officinalis enhanced antibacterial and anti-inflammatory properties, leading to improved diabetic wound closure, collagen deposition, and neovascularization. Finally, our membranes demonstrated excellent cell proliferation with no observed cytotoxicity.

A composite radome is a durable structure to protect telecommunication radar antennas against mechanical and environmental factors. The aim of this research is to investigate and optimize the mechanical (tensile strength) and electromagnetic (dielectric constant) properties of GFRP composite radome. For this purpose, the parameters of the fibers type (E series, D series and E/D series), the resin type (epoxy and polyester) and the composite manufacturing method (manual layering, vacuum bag and vacuum infusion) have been considered to optimize the mechanical and electromagnetic properties, and final cost of the composite radome. Taguchi method and the gray relational grade technique have been used to achieve the optimal conditions of the parameters. It was observed that the values of tensile strength, dielectric constant and final cost of the composite radome can be improved simultaneously using D series glass fibers, epoxy resin and vacuum bag manufacturing method.

The discharge of textile dyes into aquatic ecosystems poses severe environmental and health risks due to their toxic, carcinogenic, mutagenic, and persistent nature. These pollutants inhibit photosynthesis, disrupt aquatic biodiversity, and can bio-accumulate in food chains. These harmful impacts highlight the urgency of developing effective remediation strategies. Adsorption has emerged as a prominent technique for wastewater treatment. Surface-functionalized chitin and chitosan bio-polymeric composites (offering exceptional potential owing to their biocompatibility, tunability, and high affinity for dyes) are crucial in the adsorption of deleterious organic dyes from polluted aqueous systems. Chemical modifications such as cross-linking, grafting, and composite formation with carbon-based materials and clay or magnetic particles. These functionalizations optimize electrostatic interactions, hydrogen bonding, and π–π stacking with dye molecules, enabling efficient sequestration of diverse dyes. This review critically assesses the efficacy of functionalized chitin/chitosan composites in adsorbing textile dyes, highlighting advances in material design, adsorption mechanisms, and performance metrics. This review addresses challenges such as pH sensitivity, scalability, and regeneration, while proposing future directions for sustainable adsorbent development. By integrating material innovation with environmental considerations, this work aims to guide the efficient synthesis of adsorbent and scalable solutions for dye pollution mitigation, emphasizing the synergy between adsorption science and ecological safety.

Research Highlights

• Toxicity of textile dyes and their diverse environmental issues to living organism.

• Surface modification of chitin/chitosan.

• Adsorptive remediation textile dyes from industrial wastewater by chitin/chitosan biomaterials.

• Conclusion and future prospective of chitin/chitosan biomaterials.

Antimicrobial resistance (AMR) has emerged as a global public health crisis, largely driven by the inappropriate use of antibiotics. To address this challenge, alternative therapeutic strategies, particularly those based on natural sources, are being actively explored. This study aimed to develop and evaluate novel hydrogel formulations incorporating pomegranate seed-derived hydrochar and tamanu oil into a chitosan-PF127 matrix, with the goal of combating multidrug-resistant bacteria. The synthesized hydrogels were characterized using Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). Their antibacterial activities were assessed in vitro against Methicillin-resistant Staphylococcus aureus (MRSA; BAA-43300), carbapenem-resistant Acinetobacter baumannii (A. Baumannii, BAA-1792), Escherichia coli (E.Coli, BAA-2340), and Klebsiella pneumoniae (K. pneumoniae, BAA-1705) using disk diffusion and time-kill assays. Biocompatibility was evaluated using NIH3T3 fibroblast cells. The hydrogel formulations exhibited no cytotoxicity up to 1500 µg/mL. Among them, the tamanu oil and hydrochar-loaded chitosan-PF127 hydrogels demonstrated the highest antibacterial activity, particularly against A. baumannii, K. pneumoniae, and MRSA. Against A. baumannii, the CS-PF127-PH-T formulation produced a 14 mm inhibition zone and demonstrated significant antibacterial activity, achieving approximately 97% biofilm inhibition. SEM analysis further revealed that these hydrogels caused significant morphological disruption in A. baumannii cells. The findings suggest that these bio-based hydrogel systems have promising potential as alternative antibacterial agents for the treatment of infections caused by multidrug-resistant pathogens.

This study explores the degradation behavior of PGA/TMC and PGA/PCL copolymer surgical sutures under different pH conditions using an integrative approach that combines Mach-Zehnder interferometric technique with molecular modeling. The optical interferometry with molecular modeling enables one to understand better the long-term mechanical properties and molecular analysis of the PGA/TMC and PGA/PCL sutures in different pH solutions, thereby broadening the knowledge of surgically implanted sutures behavior under normal and abnormal physiological conditions. Mechanical behavior was assessed through phase mapping and birefringence analysis at pH 5 and 7 over 10- and 20-day periods. 3D refractive index profiles revealed internal structural changes. Density Functional Theory (DFT) and PM6 semiempirical methods analyzed electronic properties, including HOMO-LUMO gaps, 3D contour mapping, FTIR simulations, and structure–property relationship (SPR) Descriptors. Global reactivity descriptors such as ionization potential (I) and electron affinity (A) were also calculated. Results of global reactivity descriptors revealed that PGA/TMC suture exhibited higher chemical hardness and lower electrophilicity than PGA/PCL, indicating greater stability and lower reactivity. Notably, under acidic conditions, PGA/PCL showed an extremely low HOMO–LUMO gap (0.35 eV) and a very high electrophilicity index (96.94 eV), signifying high chemical reactivity and susceptibility to degradation. Computational FTIR analysis indicated degradation and chain scission in both sutures under selected pH levels. SPR analysis revealed PGA/TMC suture’s volume remained stable (204.30 ų to 208.76 ų) across pH levels, whereas PGA/PCL suture’s volume increased in acidic media (189.11 ų) compared to neutral (184.33 ų). Therefore, this study offers valuable insights into the long-term mechanical behavior and stability of PGA/TMC and PGA/PCL sutures in various pH environments. Understanding the degradation patterns of the sutures is important for optimizing these suture materials in surgical applications.

Using BASF commercial polyurethane 1185 A (TPU) as the modifying material, polyurethane-modified asphalt in varying dosages was created for this study. The rheological properties, fatigue behavior, temperature sensitivity, chemical composition, and self-healing properties of polyurethane-modified asphalt were all characterized using multi-dimensional characterization techniques, such as the dynamic shear rheometer test (DSR), bending creep stiffness test (BBR), fatigue-healing-fatigue test, Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The findings of the study indicated that adding TPU to asphalt can optimize its low-temperature performance, effectively increase its low-temperature flexibility, and greatly increase its resistance to low-temperature cracking. Excellent interfacial adhesion between the modifier and the base asphalt was found by microscopic morphological investigation. According to the results of the fatigue-healing-fatigue tests, the modified asphalt’s self-healing performance progressively improved as the TPU content rose, peaking at 6% TPU content. When the TPU concentration is 6%, the changed asphalt achieves the best overall modification effect, according to a thorough investigation of all performance metrics. This study’s findings offer a theoretical foundation for enhancing matrix asphalt’s rheological characteristics and self-healing capabilities while also prolonging the pavement’s service life.