Polymer Bulletin最新文献

Hydrogels were synthesized via ionic crosslinking between chitosan (CS), a cationic polymer, and the anionic polymers sodium polyaspartate (NaPAsp), and alginate (AG), using the semi-dissolution/acidification/sol–gel transition method. The resulting pH-responsive CS/NaPAsp/AG hydrogel exhibits an average pore diameter of 200–300 µm and a water absorption capacity ranging from 900 to 2000%. FTIR, XRD, and TGA analyses confirmed the formation of a polyelectrolyte network and SEM images showed a highly porous structure whose morphology varied with pH. Rheological studies revealed gel-like behavior and structural integrity over a wide pH range. CS-g-OA micelles exhibited spherical morphology and efficiently encapsulated coumarin-6 ( ~ 30%), employed as a hydrophobic fluorophore, while the hydrogel loaded with the micellar system achieved higher flourophore encapsulation efficiency ( ~ 53%), indicating synergistic retention of hydrophobic cargo. These properties suggest the hydrogel is well-suited for encapsulating and transporting coumarin derivatives and other hydrophobic drugs.

The present research investigates the mechanical, fatigue, creep, and dynamic mechanical properties of Aloe vera-polyester-nanocellulose composites to evaluate their structural performance and reinforcement effects. The incorporation of Aloe vera fibers significantly enhanced the mechanical properties of the composite, with further improvements observed upon the addition of nanocellulose. Specimen PAN2, containing 3 vol% nanocellulose, exhibited the highest tensile strength of 131 ± 1.0 MPa, representing a 156.9% increase compared to the unreinforced specimen. It also demonstrated superior flexural strength of 148 ± 1.7 MPa, a remarkable 134.9% improvement over the baseline, and the highest impact resistance of 60.0 ± 8.7 KJ/m², confirming its ability to effectively absorb energy and resist fracture.The same composite also exhibited the highest tensile and flexural modulus of 8.9 ± 0.3 GPa and 9.8 ± 0.3 GPa, respectively. Additionally, PAN2 displayed the best fatigue resistance, with cycles to failure reaching 23,475 ± 1120 at 25% of UTS, 20,625 ± 990 at 50% of UTS, and 17,804 ± 880 at 75% of UTS, indicating its enhanced durability under cyclic loading due to optimal stress dispersion and reduced crack propagation. However, specimen PAN3, with 5 vol% nanocellulose, exhibited the best creep resistance, recording the lowest strain values of 0.0062 ± 0.0003 at 5000 s, 0.0071 ± 0.0003 at 10,000 s, and 0.0088 ± 0.0004 at 15,000 s, which highlights its superior ability to resist time-dependent deformation. PAN3 also demonstrated the excellent storage modulus of 5.2 ± 0.2 GPa and the highest glass transition temperature of 91 ± 3 °C in the dynamic mechanical analysis, confirming its superior stiffness and thermal stability. The SEM analysis further provided insights into the micrpscopic morphology, where the plain resin matrix exhibited voids, while fiber pull-out was evident in the fiber-reinforced specimen. PAN2 displayed improved filler-matrix adhesion, contributing to its superior mechanical properties, whereas PAN3 exhibited agglomerated nanocellulose particles, which, despite acting as stress concentrators, contributed to its high creep and thermal resistance.

The surface functionalization MFe₂O₄ (M = Co, Ni, Zn) with Polyvinyl alcohol (PVA) by co-precipitation method, and serve as targeted drug delivery carriers in breast cancer therapy. The mean crystallite size of PVA@CF, PVA@NF, and PVA@ZF NCs was found to be 14.8 ± 0.3, 14.6 ± 0.3, and 9.7 ± 0.1 nm, respectively from the XRD patterns. Spherical and random shape morphology of PVA@CF, PVA@NF, and PVA@ZF NPs was observed by HRTEM with the mean particle size of 13.9 ± 0.1, 9.5 ± 0.1, and 7.4 ± 0.1 nm, respectively. RT dependent saturation magnetization 64.96, 38.94, and 20.07 (emu/g), remanence field 15.74, 0.55, and 0.02 (emu/g), and coercive field 474.45, 10.12, and 31.96 Oe were observed from M-H analysis of PVA@CF, PVA@NF, and PVA@ZF NCs, respectively. Sulforhodamine B (SRB) assay was employed to carry out anticancer activity of PVA@MF NCs against the MCF-7 cell line, and data reveals that cytotoxicity of PVA@NF was higher than PVA@CF, and PVA@NF NCs at concentrations range of 10–40 µg/ml. At high dose (80 µg/ml), % cell viability for PVA@NF (112.35%) and PVA@CF (101.09%) than the obtained for PVA@ZF (85.59%) respectively due to natural variations of cellular metabolism. The biocompatible PVA@MF NCs can be employed as a promising therapeutic agents in the applications of breast cancer therapy.

This study investigates the fabrication and characterization of hybrid epoxy composites reinforced with sisal fiber, jute fabric, and novel bio-fillers—Cashew nutshell dust (CNSD), kapok filler (KF), and wood sawdust (WSD)—using compression molding. The influence of these fillers on the mechanical, tribological, and physical properties of the composites was systematically evaluated. Results revealed that CNSD composites achieved the highest tensile strength (72 MPa), representing a 64% improvement over WSD (44 MPa) and 31% over KF (55 MPa), while also exhibiting superior impact strength (14 J/mm², 69% higher than WSD and 12% higher than KF). WSD-based composites demonstrated the greatest compressive (260 MPa) and flexural strengths (35 MPa), with respective improvements of 86% and 133% compared to CNSD and KF, along with the lowest water absorption (8.77%). KF composites showed the highest hardness and maximum water contact angle (88.15°), confirming their excellent hydrophobicity and surface resistance. SEM analyses validated improved filler–matrix adhesion and reduced voids in optimized composites. The study demonstrates that strategic selection and integration of bio-fillers in hybrid natural fiber composites can yield sustainable, high-performance materials. These findings promote the use of agricultural and industrial by-products, supporting resource efficiency and environmental sustainability, and highlight the potential of such composites for structural, automotive, and industrial applications.

The over utilization of fossil fuel based heavy materials are going to depleted in the upcoming decades and it has also demanded more fuel consumption due to high dense nature, which create pollution in the environment. To make solution for this, light weight bio polymer based composite materials are used and are welded using Friction stir welding process (FSW) to design and utilized in complicated work job. Thus, the present research aims is to study less dense nature of 3D printed PLA and ABS plate are joined by FSW and novelty of this study is to strengthen those welded material by infusing biosilica particle under the weld zone. This FSW and biosilica infused PLA/ABS composites performance are analysed by testing tensile, impact, hardness, and fatigue properties of the composite as per ASTM standard. The results of this study concluded that the maximum tensile strength of 52 MPa, impact strength of 0.39 J, and fatigue loading cycles of 20, 576 for applied ultimate tensile stress (UTS) are demonstrated by the welded composite designated A3 with a 2 vol% biosilica addition and a constant stirring speed of 500 rpm. The biosilica-infused A3 welded composite exhibits 62.5%, 116%, and 149% better tensile strength, impact strength, and fatigue life cycle, respectively, in comparison to the plain welded composite A0 without any reinforcements. However, FSW composite A4 has a surface hardness of 70 (shore-d), and a maximum of 5 vol% biosilica is added to the welded zone. Further, the microstructural analysis of the FSW composite is viewed through field emission scanning electron microscope and EDAX. Therefore, these enhanced properties in FSW composite could be used in applications such as automobiles, exterior cover parts in aerospace, spacecraft, military defense manufacturing, and infrastructure civil engineering applications, etc.

This study presents the design and fabrication of high-performance polyoxadiazole (POD) membrane materials via a multicarboxylic acid copolymerization strategy, systematically elucidating the structure-property relationships.Using polyphosphoric acid as the solvent medium, gradient polycondensation was carried out with dihydrazide terephthalate and varying ratios of cyclopentanetetracarboxylic acid (CPTA), ethylenediaminetetraacetic acid (EDTA), and ethylene glycol bis(2-aminoethyl ether) tetraacetic acid (EGTA). By tuning the steric effects of the tetracarboxylic acids monomers, the polymer chains underwent a structural transformation from two-dimensional linear arrangements to three-dimensional cross-linked networks. Comprehensive characterization, including FT-IR spectroscopy, thermogravimetric analysis (TGA), and scanning electron microscopy (SEM), was employed to investigate the chemical structure, thermal stability, and membrane morphology. The modified POD membranes demonstrated enhanced oxidation resistance, water absorption control, and superior mechanical properties. Notably, the E-POD₂ sample achieved a maximum tensile strength of 151.64 MPa, highlighting its strong potential for advanced membrane applications. Among them, E-POD₂ demonstrated the best overall performance in terms of mechanical strength, oxidation resistance, and water absorption control.

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In this study, we successfully prepared carbonized/dextrinated-starch (CDS) modified with biological modifiers and investigated its adsorption properties. The morphological features of different modified starch (S) and CDS were characterized using multiple analytical techniques. Adsorption behaviors of CTC and Pb(II) were evaluated via batch experiments, and the effects of pH, temperature, and ionic strength on adsorption were compared. Morphological analyses confirmed successful surface modification by biological modifier, which altered the physicochemical properties of S and CDS. Both the Langmuir and Freundlich models were suitable for describing the adsorption process of CTC and Pb(II). The maximum adsorption capacities of CTC and Pb(II) on different modified materials were 14.06–25.82 mmol/kg and 388.70–807.52 mmol/kg, respectively, following the trends: SA-modified > AE-modified > unmodified material and modified CDS > modified S. Higher temperature and pH promoted the adsorption of CTC and Pb(II), and the process was an endothermic, spontaneous, and entropy- increasing reaction. The adsorption capacity for both CTC and Pb(II) initially increased and then decreased as the ionic strength increased. Moreover, the modified CDSs were practical and environmentally friendly for the treatment of CTC and Pb(II).

The liver is an essential organ that keeps normal functioning in the body. The vascular architecture causes major bleeding, especially after trauma and liver resection surgeries. Massive bleeding creates major challenges, requiring complex hemostatic treatments. This study describes the development and evaluation of a multifunctional carboxymethyl chitosan/gelatin/pectin bioadhesive infused with tranexamic acid (TXA) and crosslinked with calcium chloride (CaCl₂) for enhancing hepatic hemostasis. To make the bioadhesive, we dissolved carboxymethyl chitosan (CMCs), gelatin, and pectin in deionized water. We included TXA at concentrations of 0, 5, 10, 50, and 100 mg/mol and combined it with 100 mM CaCl₂. We carefully studied the physical and chemical parameters, including porosity, pH, water absorption, biodegradation, and TXA release. In vitro analyses examined blood compatibility, blood clotting index, cell viability via the MTT assay, and anti-inflammatory effects, while in vivo studies in Wistar rats undergoing partial hepatectomy assessed hemostatic performance. The K2 bioadhesive (10 mg/mol TXA) worked the best. It stopped blood loss in 20 s, kept cells alive at about 90%, and caused hemolysis in less than 5% of cases. The bioadhesive’s ability to break down while releasing TXA suggests that it could be a good way to stop bleeding in people with liver problems. These results could change how doctors treat bleeding wounds and how often they need to give blood transfusions. Subsequent research should employ more extensive animal models to investigate longevity and clinical relevance.

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Biopolymer-based hydrogels have emerged as versatile platforms for water purification due to their tunable structure, high hydrophilicity, and environmental compatibility. In this comprehensive review, we evaluate recent progress in the development and application of cellulose-, starch-, and chitosan-derived hydrogels for the adsorption of heavy metal ions from contaminated water. Emphasis is placed on the synthesis strategies, structural modifications, physicochemical characteristics, and functional group interactions that enhance adsorption capacity and selectivity. The role of crosslinking methods, polymer blends, and composite formulations is critically examined in relation to their mechanical integrity and regeneration potential. Moreover, we discuss adsorption isotherms, kinetic models, and thermodynamic behavior reported in the literature to highlight structure–function relationships. Challenges related to stability, reusability, and scale-up are also identified, along with emerging approaches such as stimuli-responsive hydrogels and nanocomposite designs. This review underscores the significance of macromolecular engineering in tailoring biohydrogels for sustainable and efficient removal of toxic metal ions, offering guidance for future development in water remediation technologies.

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The escalating global consumption of plastics has intensified environmental concerns due to the persistence and non-biodegradable nature of petroleum-derived polymers. India is ranked as the third-largest plastic producer in 2019, generating nearly 17 million metric tons, highlighting the urgent need for sustainable material alternatives. Bioplastics have emerged as promising candidates due to their renewable origin, reduced carbon footprint, and biodegradability, yet only a small portion of the 2.36 million tons produced in 2021 were truly biodegradable, even as global plastic production is projected to reach 338 million tons by 2029. Asia is expected to drive the transition toward eco-friendly materials, with biodegradable bioplastic production anticipated to increase from 0.88 million tons in 2021 to 5.3 million tons by 2030. This review examines the mechanisms, fabrication routes, and applications of bioplastics derived from starch, cellulose, proteins, chitosan, lignin, Polylactic Acid (PLA), Polyhydroxyalkanoates (PHA), Polyhydroxybutyrate (PHB), Polyvinyl Alcohol (PVA), and bio-based polyethylene. Fabrication methods including solution casting, microbial fermentation, enzymatic synthesis, and polymer blending along with the use of plasticizers, fillers, and crosslinkers, are discussed for property enhancement. Bioplastics are increasingly applied in packaging, agriculture, biomedical devices, automotive components, cosmetics, and controlled-release systems. Their degradation behavior and environmental performance are assessed through standardized biodegradation assays, reflecting their growing relevance in sustainable materials development.