This work presents a circular economy approach by developing hybrid jute/epoxy composites enhanced with nanographene (0–5 wt
Polyurethane (PU) elastomers are widely used in advanced applications; however, conventional polyurethanes suffer from irreversibility, leading to the poor self-healing and limited recyclability. To address these issues, a series of self-healing polyurethane elastomers (PURs) with dual dynamic networks, derived from a specifically designed chain extender consisted of 4,4’-diaminodiphenyl disulfide (4-AFD) and N,N-bis(2-hydroxyethyl)-3-aminopropionamide (OH-AAM-OH), was prepared through regulating the molar ratio (R) of 4-AFD and OH-AAM-OH. The results indicate that as the 4-AFD content increases, the glass transition temperature (Tg) and the tensile strength gradually improve; PU0:1, in which only OH-AAM-OH was used as the chain extender, exhibits the distinct stress-induced crystallization (SIC) behavior due to its higher segment flexibility and enhanced hydrogen bonding. Furthermore, PU1:1 (with a 1:1 molar ratio of 4-AFD to OH-AAM-OH) achieves the self-healing efficiency as high as 94.6
Waste plastics derived from petroleum sources pose a serious global challenge, and their recycling represents an effective strategy from both environmental and economic perspectives. Expanded polypropylene (EPP), widely used in various industrial sectors, is generated in considerable quantities as waste. Waste EPP was functionalized with green-synthesized Ag and thermally processed graphite-derived carbon to prepare flat-sheet composites via thermally induced phase separation (TIPS). The composites were characterized by XRD, SEM, FTIR, and TG-DSC analyses, and their adsorption and UV/H₂O₂-assisted dye removal performances were evaluated using methyl orange (MO) as a model pollutant. Adsorption efficiencies remained limited, reaching 10.5
Reducing internal concentration polarization (ICP) through advanced techniques and materials is essential for enhancing the efficiency of the forward osmosis (FO) process. In this study, a microfiltration (MF) membrane substrate was coated with an interlayer to fabricate a highly efficient thin-film composite (TFC) membrane. The interlayer was formed by in situ crosslinking of polyvinyl alcohol (PVA) and glutaraldehyde on the surface of the MF substrate via a layer-by-layer strategy. By controlling the number of coating layers, the support’s surface characteristics, such as hydrophilicity, porosity, and pore size, were fine-tuned. This tailored support layer served as the substrate for interfacial polymerization, which was used to deposit the polyamide (PA) layer. A detailed analysis was conducted to establish a correlation between the support layer’s surface properties and the morphology of the PA layer. Results show that reducing surface pores limits amine monomer diffusion, but nanobubble confinement forms a rough surface. The water flux in the FO process improved significantly, rising from 8.1 LMH in the control TFC membrane to 18.1 LMH in the TFC-PG0.25-3 membrane. This enhancement is attributed to improved PA-layer characteristics, including reduced thickness, increased hydrophilicity, and higher roughness, all of which were facilitated by the interlayer. The findings of this study offer valuable insights into the development of interlayered TFC membranes, demonstrating their potential for enhanced efficiency in different applications.
An antistatic agent, poly(aniline-amino-carbon nanotube) (PANI-A-CNT), was prepared using emulsion polymerization. Melt‑blending of ABS resin with C12mimBr and PANI‑A‑CNT yielded the antistatic PANI‑A‑CNT/IL/ABS composites. A parallel set of IL‑free blends was also made to serve as a control. Transmission electron microscopy (TEM) analysis showed that C12mimBr promotes the dissociation of carbon nanotube bundles. This effect enhances the dispersion uniformity of the PANI‑functionalized carbon nanotubes in the ABS substrate. As a result, a more complete conductive network forms within the ABS resin, which enhances the antistatic performance of the composite. With 4 wt
The aviation industry is committed to reducing its CO₂ emissions. One approach is the use of materials with a lower carbon footprint. With that in mind, a bio-based polyamide (PA) compound for use in aircraft cabin components is developed. Apart from requirements in high mechanical performance and flame retardancy, the developed material should be appropriate for robot-assisted additive manufacturing (RAM). This manufacturing method allows for a reduction in component weight and, consequently, CO₂ emissions. Since aircraft cabin components are produced in small quantities that require a lot of manual effort during production, RAM is an ideal automated manufacturing method. This study fills a gap in literature, as systematic studies combining bio-based matrices, halogen-free flame retardants (FR), and glass fiber reinforcement are rare. Different FR and their combinations are evaluated in bio-based PA matrices. Additionally, glass fiber reinforcement is used to achieve the desired mechanical properties. The tested PA610 and PA11 have low flammability but poor mechanical properties. The final PA1010-based compound meets all defined requirements and achieves a tensile strength of 102 MPa, an elongation at break of 5
Uncontrolled bleeding and secondary bacterial infections are major challenges in emergency trauma care and surgery, making the development of dressings with rapid hemostatic and efficient antibacterial functions clinically significant. In this study, a multifunctional hydrogel was prepared by covalently grafting tannic acid (TA) onto chitosan (CS), cross-linking the composite with gelatin and oxidized dextran via dynamic Schiff base reaction, and introducing ε-poly-L-lysine. TA-CS interactions enhanced the structural stability and antioxidant capacity of the hydrogel. In vitro experiments confirmed its excellent hemostasis (minimum clotting index 35.54
Monodisperse macroporous poly(GDMA-co-GDGDA) microparticles were synthesized by a multistage seeded microsuspension polymerization method using monodisperse poly(glycidyl methacrylate) (poly(GMA)) seed latex particles. The morphology and physicochemical properties of the resulting polymer particles were characterized by optical microscopy, scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET) surface area measurements, and laser diffraction particle size analysis. Surface epoxy groups were subsequently converted into azide functionalities through nucleophilic epoxide ring-opening with sodium azide (NaN₃), followed by copper(I)-catalyzed azide–alkyne cycloaddition (CuAAC) with propiolic acid, resulting in the covalent incorporation of triazole-linked carboxylic acid groups onto the particle surface. After purification, the functionalized particles were packed into a stainless-steel column (4.6 × 150 mm), and the chromatographic performance of the prepared stationary phase was evaluated using representative polar analytes under hydrophilic interaction liquid chromatography (HILIC) conditions. Systematic optimization demonstrated that an ACN/H₂O ratio of 90/10 (v/v), a mobile phase flow rate of 1.0 mL min⁻¹, and approximately neutral mobile phase conditions (pH ≈ 7) provided the best overall chromatographic performance. At lower acetonitrile contents (80/20 and 85/15, v/v), thiourea and inosine co-eluted, whereas complete baseline separation was achieved at 90/10 (v/v) ACN/H₂O. Further increasing the acetonitrile content to 95/5 (v/v) resulted in excessive retention and peak broadening. Experimental evaluation of column efficiency showed that the minimum reduced plate height was obtained at approximately 1.0 mL min⁻¹, consistent with the Van Deemter model. The results further indicated that analyte retention was governed predominantly by hydrophilic partitioning, while hydrogen bonding, dipole–dipole interactions, and possible electrostatic interactions provided additional contributions to chromatographic selectivity. These findings demonstrate that the prepared propiolic-acid-functionalized poly(GDMA-co-GDGDA) stationary phase exhibits the characteristic chromatographic behavior of HILIC materials and represents a promising polymer-based stationary phase for the efficient separation of polar analytes.
The design of amphiphilic thermoresponsive block copolymers enables the development of nanostructured systems for controlled drug delivery. In this context, we report the synthesis of a well-defined triblock copolymer, poly(N-isopropylacrylamide)-b-poly(3-hydroxybutyrate-co-3-hydroxyvalerate)-b-poly(N-isopropylacrylamide) (PNIPAAm-b-PHBHV-b-PNIPAAm), via reversible addition–fragmentation chain-transfer (RAFT) polymerization and its self-assembly into thermoresponsive micellar structures, with potential application in drug delivery. Hydroxyl-terminated PHBHV was prepared by transesterification with ethylene glycol, followed by bromination and xanthate substitution to yield a PHBHV-based macro-RAFT agent (EX-PHBHV-EX). Subsequent RAFT polymerization of N-isopropylacrylamide (NIPAAm) afforded the target PNIPAAm-b-PHBHV-b-PNIPAAm triblock copolymers. The copolymers were thoroughly characterized by Fourier-Transform Infrared (FTIR) spectroscopy, Proton Nuclear Magnetic Resonance (1H NMR) spectroscopy, Size Exclusion Chromatography (SEC), Differential Scanning Calorimetry (DSC), and X-ray Diffraction (XRD), confirming the structural integrity and tunable segment composition. The critical micelle concentration (cmc) of the block copolymers increased with longer PNIPAAm chains and decreased with longer PHBHV segments. Dynamic Light Scattering (DLS) revealed that micellar size increased with increasing hydrophobic PHBHV block length and decreased with increasing hydrophilic PNIPAAm block length. Additionally, temperature-dependent DLS experiments confirmed the thermoresponsive behavior of the micelles, showing a reduction in the hydrodynamic diameter at physiological temperature (37 °C) due to the collapse of the PNIPAAm chains.
Nowadays, the most widely used vulcanization system for industrial rubber products is the traditional sulfur vulcanization system, which releases harmful gases and makes unsustainability for the development of rubber industry. Herein. In this study, the novel poly(Malic Acid) (PMA) is prepared by direct polymerization, the structure of PMA was confirmed by FTIR and 1HNMR, weight average molecular thermal stability of PMA is 4860 g/mol and 214 °C. Based on prepared EESBR with (Epoxidized emulsion styrene butadiene rubber) different epoxidized degrees, it was cured by PMA. It was found that PMA cured EESBR exhibits typical vulcanization behavior, with the increase of PMA addition, the crosslinking density increased to 9.39 × 10− 4 mol/cm3, and the tensile strength of PMA/EESBR gradually increased to 2.82 MPa, maximum torque (MH) can reach to 4.70 N*m. The value of tanδ at 60 °C and 0 °C are 0.0215 and 0.8625 respectively, exhibiting high wet skid resistance and low rolling resistance as a green tire tread. After one reprocessing properties of EESBR/PMA, the recovery rate is only 50
Biodegradable films with enhanced barrier, UV- shielding, antimicrobial and mechanical properties are highly desirable for food packaging, protective coatings and biomedical applications. In this context, Polyvinyl Alcohol (PVA) composite films reinforced with bio-derived Silicified Microcrystalline Cellulose (SMCC) and Zinc Oxide (ZnO) nanoparticles were fabricated to develop biodegradable multifunctional films with enhanced properties. Bare PVA, PVA/MCC and PVA/SMCC films were also fabricated to assess the individual and synergistic effect of Microcrystalline Cellulose, SMCC and ZnO nanoparticles on the overall performances of films. On analysis, PVA/SMCC showed reduced water uptake and water vapour transmission compared to PVA/MCC while PVA/SMCC-ZnO exhibited the lowest moisture absorption by restricting polymer chain mobility. Antibacterial studies revealed no activity for PVA, PVA/MCC and PVA/SMCC, while PVA/SMCC-ZnO film exhibited a distinct inhibition zone of 11 mm against both E. coli and S. aureus, which is attributed to ZnO induced reactive oxygen species generation and membrane disruption. Soil burial studies demonstrated that MCC enhances the biodegradability of PVA, while SMCC and ZnO suppresses the biodegradation due to their antimicrobial nature. FE-SEM analysis supported these findings, revealing severe surface deterioration in PVA/MCC films, moderate degradation in PVA/SMCC, and minimal morphological changes in PVA/SMCC–ZnO films. Contact angle increased from 67.3° (PVA/MCC) to 86° (PVA/SMCC) and 92° (PVA/SMCC–ZnO), indicating enhanced hydrophobicity. Mechanical testing indicated that PVA/SMCC–ZnO possessed superior tensile strength with reduced elongation at break. Overall, the synergistic interaction of SMCC and ZnO significantly enhanced the barrier, antibacterial, and mechanical performance of PVA, underscoring their suitability for advanced packaging applications.
Polylactic acid (PLA) poses significant challenges in practical processing and application because of its inherently slow crystallization kinetics. This paper proposes a green and low-cost modification strategy by investigating the effect of waste biomass, tomato peel residue (TP), on the crystallization performance and melting behavior of PLA. The results demonstrate that TP with an average particle size of 4.56 μm after ultrafine grinding can significantly promote the crystallization process of PLA. Under isothermal crystallization conditions at 96 °C, the addition of 5 wt
Acrylate-based compositions with Irgacure 784 are widely used for photopolymerization. However, the inherent limitations of this method require subsequent heat treatment to eliminate residual monomers. In this work, a previously unconsidered thermally initiated polymerization of acrylates with Irgacure 784 was investigated. Polymerization was studied in an isoconversion mode with varying heating rates, the content of molecular oxygen in the reactor atmosphere, as well as with different contents of functional carbon particles - astralenes. The kinetic parameters of the process were determined using the Friedman method. It has been established that polymerization occurs at temperatures above 150 °C and is accompanied by destruction of the monomer. The effective activation energy of thermally initiated polymerization is 90–115 kJ/mol and is comparable to the energy of radical polymerization of acrylate esters. The addition of astralenes slightly inhibits polymerization kinetics but improves the properties of the material in concentrations up to 0.05
The synergistic removal of wastewater containing heavy metals and organic pollutants remains a major challenge. Although multifunctional materials can enable one-step treatment, their high cost limits practical application, making sequential treatment with single-functional materials a feasible strategy. In this study, two lignin-based hydrogels were developed for stepwise removal of heavy metals and tetracycline (TC). Iron-manganese-modified lignin hydrogel (IM-LH) was prepared by copolymerizing acrylamide with lignin, in situ loading iron and manganese ions, and subsequent sulfuration, enabling efficient adsorption of Cd(II) and As(III). The immobilized enzyme composite hydrogel (HRP@HPAAM-LA) is made by chemically attaching horseradish peroxidase (HRP) to the pores and surfaces of a lignin-based semi-interpenetrating network carrier (HPAAM-LA), which is built through free radical copolymerization, using an EDC/NHS-mediated amidation reaction. This material can both adsorb and concentrate TC while letting HRP carry out oxidative degradation. The hydrogels were characterized by SEM, FTIR, XRD, XPS, and TGA, and their continuous removal performance and mechanisms were investigated. Both hydrogels exhibited uniform porous networks and abundant active sites. IM-LH showed maximum adsorption capacities of 86.20 mg·g− 1 for Cd(II) and 60.01 mg·g− 1 for As(III), retaining removal rates of 65.46
The development of multifunctional elastomeric composites of simultaneously improving thermal durability and fire resistance remains a key challenge for EPDM-based materials. Herein, we report a flame-retardant composite, where barium metaborate (BBO) was synthesized and incorporated into EPDM at different loadings to explore its potential as a ceramic multifunctional filler. The synthesized BBO was characterized by ATR–FTIR and UV–Vis spectroscopy, revealing the characteristic borate structure and a wide optical band gap of approximately 3.95 eV. The influence of BBO on curing characteristics, thermal decomposition behavior, degradation kinetics, and flame-retardant performance of EPDM was subsequently investigated. Following BBO incorporation, rheological analysis revealed accelerated vulcanization and enhanced elastic network development. Moreover, thermal analysis demonstrated delayed decomposition, increased activation energy, and higher residual mass compared with unfilled EPDM. As a result, the BBO-filled composites exhibited enhanced resistance to thermo-oxidative degradation. From the findings, the burning rate decreased from 3.33 to 1.67 mm s⁻¹ as the BBO loading increased, corresponding to an approximately 50
Smart drug delivery systems based on pH-responsive mechanisms have attracted significant attention for targeted and controlled drug release. In this study, polycaprolactone (PCL) films loaded with 7 wt
Graphene oxide/poly(N, N-diethyl acrylamide) (GO/pDEA) composite hydrogels were synthesized via thermally initiated free-radical polymerization using different crosslinker contents and evaluated as adsorbents for Congo red removal from aqueous solutions. The obtained materials were characterized by FTIR, SEM, and XRD analyses, which confirmed successful incorporation of graphene oxide into the hydrogel network and the formation of a predominantly amorphous, highly porous composite structure. Swelling studies demonstrated that the swelling degree was primarily governed by the crosslinking density, whereas the effect of solution pH was relatively limited. The adsorption behavior was strongly influenced by the solution pH, with the highest adsorption capacity achieved under alkaline conditions (pH 10). Equilibrium adsorption was best described by the Sips and Freundlich isotherm models, indicating adsorption on energetically heterogeneous active sites, while the pseudo-first-order kinetic model showed the best agreement with the experimental data, suggesting that adsorption is predominantly controlled by rapid occupation of readily accessible surface sites. The maximum adsorption capacity predicted by the Langmuir model was 21.03 mg g⁻¹, which is in excellent agreement with the experimentally determined value of 21.4 mg g⁻¹, confirming the consistency of the obtained adsorption parameters under the applied experimental conditions. Furthermore, the GO/pDEA composite retained 89.4
This study aimed to develop, optimize, and evaluate a topical delivery system based on hyaluronic acid (HA)-loaded microsponges to develop sunscreen and achieve a long-term release of HA, which increases the hydration of the mixture and thus enhances its stability. The HA-loaded microsponges were prepared using the solvent diffusion method in the emulsion, where the concentration of ethyl cellulose (EC) was changed to study its effect on the physical properties of the microsponges. The study included the use of scanning electron microscopy (SEM), surface potential measurement (Zeta potential), and infrared spectroscopy (FTIR) to characterize the microsponges. The effect of microsponges on the efficacy and stability of the sunscreen and the evaluation of the drug release in vitro. Ultraviolet-Visible (UV-Vis) was also used to characterize the sun protection factor (SPF). The rheological behavior of ISDIN sunscreen before and after adding microsponge was tested through viscosity curves, flow curves, and fit curves at different temperatures using a cone-plate viscometer. The drug-polymer compatibility analysis was also performed using FTIR spectroscopy, which revealed no interactions between HA molecules and EC, and confirmed the successful retention of HA inside the microsponge. Scanning electron microscopy (SEM) confirmed the spherical and porous nature of the prepared microsponge. The results showed that the prepared microsponge had a diameter of 18.536–24.953 μm and that the stability was good as shown by zeta potential. Carbonyl Index (CI) analysis confirmed that M3 formulation provided superior oxidative stability compared to ISDIN and other microsponge formulations. This was attributed to the gradual release of HA, which enhanced antioxidant performance and reduced degradation over time. As a result, the HA loaded microsponge contributed to improving the stability of the sunscreen.
The growing demand for lightweight, sustainable materials in additive manufacturing has driven the development of advanced polymer composites with enhanced mechanical performance. In this study, PLA-cenospheres composite filaments were fabricated via pellet extrusion to enhance mechanical strength while promoting eco-friendly material use. The incorporation of 10 wt
