Journal of Polymer Science最新文献

Synthetic poly(4-hydroxybutyrate) (P4HB), a flexible and biodegradable polymer, shows great promise in improving the toughness of poly(lactic acid) (PLA), but the inherent immiscibility of PLA and P4HB compromises the toughening efficiency. To address this issue, P4HB grafted glycidyl methacrylate (P4HB-g-GMA) is synthesized for the purpose of enhancing the compatibility within the PLA/P4HB blend. The epoxy groups on P4HB-g-GMA can form strong chemical bonds with PLA chains and remain compatible with P4HB. Rheological data confirm that adding P4HB-g-GMA enhances polymer chain entanglement. Therefore, the phase interface of the blend becomes more diffuse, leading to improved mechanical performance. Specifically, a 3D-printed PLA/P4HB/P4HB-g-GMA blend containing 8% P4HB-g-GMA (PLA/P4HB/G8) achieves an elongation at break of 161.5%, approximately 22.7 times higher than that of a PLA/P4HB blend without the modifier. Moreover, the PLA/P4HB/G8 blends show a higher volume expansion ratio (VER) and better cell morphology due to the increased melt strength from P4HB-g-GMA. This study demonstrates a simple and efficient method to improve the compatibility between PLA and P4HB, resulting in superior mechanical performance of PLA/P4HB blends and broadening their potential applications in foaming.

Sodium alginate is used in wound care because of its hydrogel-forming properties and ability to protect the wound. Copper nanoparticles have properties that inhibit the growth of microorganisms and mediate the production of essential biomolecules for the healing process, making them an excellent choice for constructing nanocomposites for wound treatment. This work aimed to synthesize copper nanoparticles using an aqueous extract of Turnera subulata Sm. and incorporate them into sodium alginate to obtain films with healing potential. The proposed system was characterized by ultraviolet–visible spectroscopy (UV–vis), Fourier-transform infrared (FTIR), dynamic light scattering (DLS), atomic force microscopy (AFM), x-ray crystallography, and biocompatibility verified by hemolysis test. The UV–vis analysis showed that CuO NPs absorb at 280 and 404 nm. The FTIR spectra revealed stretching and folding modes of the functional groups present in the aqueous extract of T. subulata responsible for the reduction/stabilization of the copper ion, as well as signals at 780 and 618 cm⁻¹ originating from the CuO bond. Size estimation using DLS revealed 564.5 and 394.2 nm. AFM data showed that adding copper oxide nanoparticles (CuO NPs) changed alginate roughness, and surface imaging revealed a material with a uniform appearance. The hemolysis test showed hemocompatibility of CuO NPs at all tested concentrations. Histology showed that CuONP-loaded alginate films accelerated the healing process.

Microencapsulation strategies enable the confinement of sensitive active materials in a protective shell, giving capsules with applications across pharmaceuticals, foodstuffs, agriculture, textiles, cosmetics, and energy storage. Among the different approaches, the soft template encapsulation method is a widely used technique that leverages emulsions as templates and forms spherical microcapsules with a liquid core and polymeric shell. Within the emulsion template umbrella, interfacial polymerization, phase internal phase separation, and polymer precipitation can all be used. The main limitation of interfacial polymerization is that the core will inevitably contain impurities such as residual monomers, which can affect the performance of the encapsulated material. This is especially relevant when performance efficiency strongly depends on its pristine composition. In this perspective, we focus on polymer precipitation soft-template strategies for capsule formation, and the complementarity of this approach to the more widely used interfacial polymerization. Polymer precipitation strategies enable the encapsulation of sensitive cores (or payloads) and can include those that are viscous, hygroscopic, and reactive.

To address the issue of electrochemical performance degradation resulting from redox reactions during the charging and discharging of supercapacitors, we introduced a novel electrode material featuring a core–shell attachment structure (PANI@(MnO₂ + NiO)) with the incorporation of carbon nanotubes (CNTs). The introduction of CNT on top of the core–shell structure by a simple chemical synthesis method helps to improve the double-layer capacitance and Faraday capacitance of the composite. Thus, multiple synergistic effects can be produced to improve charge storage capacity. The morphology structure and electrochemical properties of PANI@(MnO₂ + NiO)@CNT were analyzed. In a three-electrode configuration, the specific capacitance of the composite is 327 F g⁻¹ at a current density of 0.5 A g⁻¹. Remarkably, the capacitance retention rate exceeded 75% after 5000 charge–discharge cycles. Calculations indicate that in a supercapacitor employing a 1 M Na₂SO₄ electrolyte, the composite demonstrated energy and power densities of 48.1 W h kg⁻¹ and 999.9 W kg⁻¹, respectively. This kind of core–shell structural composites achieved electrochemical properties in line with expectations through a simple chemical synthesis method. As a practical application of supercapacitor electrode materials, PANI@(MnO₂ + NiO)@CNT have better electrical properties than similar materials and have broad application prospects in industrial production.

A novel ternary polycarbazole/cadmium sulfide/hematite iron (III) oxide (PCz/CdS/α-Fe₂O₃) nanocomposite was synthesized through in situ chemical polymerization method. The phase structure and morphology of PCz, PCz/CdS, PCz/α-Fe₂O₃, and PCz/CdS/α-Fe₂O₃ were analyzed using XRD and FESEM techniques. From HR-TEM study, particle size of PCz/CdS/α-Fe₂O₃ nanocomposite was found to be 68.09 nm. The chemical composition and the binding energy of the elements present in PCz/CdS/α-Fe₂O₃ nanocomposite were examined through XPS. BET studies revealed the mesoporous nature of PCz/CdS/α-Fe₂O₃ with a large surface area (35.51 m² g⁻¹) compared to PCz/α-Fe₂O₃ (21.52 m² g⁻¹) and PCz/CdS (7.47 m² g⁻¹) nanocomposites. Cyclic voltammetric studies revealed the highest specific capacitance (634.14 Fg⁻¹) of ternary PCz/CdS/α-Fe₂O₃ electrode in KOH electrolyte in comparison to H₂SO₄ (49.44 Fg⁻¹) and Na₂SO₄ (79.94 Fg⁻¹) electrolytes at a scan rate of 3 mVs⁻¹. Cyclic stability test indicated a high capacitive retentivity of PCz/CdS/α-Fe₂O₃ (97%) electrode than PCz/CdS (90%) and PCz/α-Fe₂O₃ (93%) electrodes after completion of 2000 cycles. From EIS, PCz/CdS/α-Fe₂O₃ displayed a low ESR value (1.35 Ω) than the binary electrodes; the value increased slightly after the cyclic stability analysis. All these indicate the effectiveness of PCz/CdS/α-Fe₂O₃ as a suitable electrode for supercapacitors.