Journal of Polymer Research最新文献

Membrane technologies are widely used as the backbone of separation and purification processes. Among fabrication process, phase inversion (PI) techniques are extensively utilized for fabricating microporous polymer membranes, offering significant advantages in environmental sustainability and operational efficiency. This review offers a comprehensive evaluation of contemporary strategies for membrane fabrication using various PI methods, including nonsolvent-induced phase separation (NIPS),vapor/evaporation-induced phase separation (VIPS),evaporation-induced phase separation (EIPS), and thermally induced phase separation (TIPS). The discussion emphasizes the thermodynamic and kinetic phenomena that govern membrane formation, while addressing the challenges and innovations in optimizing membrane structure and performance. By carefully controlling variables such as solvent types, polymer concentration, and temperature, PI processes can be fine-tuned to produce membranes with tailored characteristics. These membranes are suitable for a broad spectrum of separation technologies, spinning from water treatment to gas separation. Finally, recent application of gas separation for membrane phase inversion was discussed.

Paromomycin is an aminoglycoside antibiotic widely used for cutaneous leishmaniasis therapeutics, which is considered a neglected disease by World Health Organization. Some recent studies have revealed that the patient adhesion to the treatments of cutaneous leishmaniasis with ointments form is low because it is a long-term treatment. Therefore, hydrogels are an interesting alternative to the ointment forms. Poly(vinyl alcohol) hydrogels, known for their biocompatibility and biodegradability, offer promise for paromomycin drug delivery systems. This study investigates the feasibility of cryogelated poly(vinyl alcohol) hydrogels containing sepiolite nanoparticles for controlled paromomycin release. Cryogelation, utilizing freeze-thaw cycles, creates physical crosslinks within the poly(vinyl alcohol) matrix and sepiolite was incorporated to modify hydrogel transport properties. The obtained hydrogels were characterized by DSC, TGA, and XRD. Swelling behavior in simulated body fluid showed that nanostructured hydrogels reached up to 254%. The presence of SEP and the freezing-thawing cycles increased the diffusion coefficient of the hydrogels by 150%. Chemometrics analyses were performed from the different results to optimize the number of freezing-thawing cycles and the sepiolite content on the release of paromomycin, resulting in 5 cycles and 1% SEP as the optimum condition. These initial findings suggest the potential of PVA-sepiolite hydrogels as a platform for controlled paromomycin delivery, particularly relevant for leishmaniasis treatment.

Biofibers are used to develop ecofriendly products for the automotive and construction industries. These industries are evolving towards using natural fibers (NFs) with good damping properties and particulate-reinforced polymer composites as structural elements. This study investigates the effect of mechanical, morphological, and frequency damping properties of a fish tail palm (FTP) fiber epoxy composites with various chemical treatments. The experimental strategy demanded creating borassus flabellifer male inflorescence biochar (BFMIB) filler from biomass waste and FTP fiber from palm trees to make them more compatible with the epoxy matrix. The epoxy composites reinforced with alkaline treated (ALT) and acetic acid- chemical treated (CT) FTP fibers were prepared using the wet hand lay-up technique, incorporating BFMIB filler at varying concentrations (0–15 wt%). FTPF/BFMIB increases the mechanical properties (MPs) of epoxy composites. 10 wt% of BFMIB and NaOH treated FTPF combination exhibit higher tensile strength (TS). The highest TS of the ALT treated fiber with 10 wt% of BFMIB biochar composite (FTPF20-BFMIB10) is 103 MPa, which is 28.44% and 39.8% higher than that of the untreated (UT) and acetic-treated (ACT) FTPF/epoxy composites, respectively. Additionally, the investigation of the vibration behaviour exhibited improved damping capabilities, suggesting the possibility of vibration dampening applications. The first mode of vibration behaviour for all the interleaved FTPF/BFMIB composites had a damped natural frequency and damping ratio in the range of 126–178 Hz and 0.0321–0.0712.

The study of star A–B diblock copolymers has garnered growing attention due to their unique physicochemical properties, which are strongly governed by incompatibility effects between their constituent blocks. Unlike their linear counterparts, star-shaped architectures exhibit distinct behaviors in micellization and phase separation, making them attractive for advanced materials design. While linear diblock copolymers have been the subject of extensive theoretical and experimental investigations, systems with more complex topologies such as star polymers remain relatively underexplored from a theoretical standpoint. In this work, we investigate the static scattering of mixtures composed of star diblock copolymers and homopolymers. Specifically, we analyze the scattering behavior of star A-B diblocks copolymers in the melt state, mixed with homopolymers, and in solution using the Random Phase Approximation. In this approximation, the absolute intensity measured by small-angle neutron scattering is determined only by the structure factors of the core or corona part of the star polymer, which depends on the type of homopolymer in the mixture. The angular variations of the structure factors S_BB(Q) and S_AA(Q), accessible by neutron scattering when homopolymers A and B are added to the star diblock copolymers, are graphically illustrated for various values of physicochemical parameters. The results reveal the appearance of a correlation peak for all considered parameter values and a more or less significant dependence of the scattered intensity at the thermodynamic limit. These findings are in qualitative agreement with the experimental observations reported by Adhikari et al., underscoring the critical role of homopolymers in determining phase behavior.

Solid polymer electrolytes (SPEs) are flexible and exhibit wide application prospects. However, their low ionic conductivity at room temperature largely restricts their practical use in next-generation solid-state lithium batteries. A composite polymer electrolyte (CPE) that combines the advantages of soft chains and rigid particles is constructed to balance the electrochemical properties and mechanical strength. Hydrophobic nano-fumed silica (SiO₂) fillers are uniformly distributed in the dense cross-linking -CH₂-CH₂O- network, which is composed of polyethylene oxide and tetraglyme that is triggered by ultraviolet irradiation. The increasing amorphous region of the resulting CPE, due to the cross-linking and nanoparticles doping, facilitates an excellent electrochemical property with an ionic conductivity of 0.29 mS·cm^− 1 and a lithium transference number of 0.60 at room temperature. Moreover, the compact film with a tensile elongation of 57% can provide close interfacial contact and ensure more security for cells at work. The assembled Li||LiFePO₄ cells can deliver a reversible specific capacity of 160 mAh g^− 1 at 0.1 C at room temperature and a capacity retention of 98% after 100 cycles. This study proposes a novel method for creating high-performance composite solid electrolytes at room temperature.

Modification in the starch from micro to nanoscale plays an important role to enhance its functional properties and its application. Nowadays, starch nanoparticles are used as a sustainable alternative to common nanomaterials in healthcare due to its remarkable properties like biocompatibility, non-toxicity, and biodegradability. In the present study, starch nanoparticles are synthesized by physical, chemical, and biological methods. Raw starch of Fagopyrum esculentum were treated with gamma radiation, UV-radiation, ultrasonication, and enzymolysis method to obtained starch nanoparticles (StNPs). These nanoparticles were characterized using FESEM, DLS, FTIR, and XRD. Among all, average size (193 nm) and surface area (1.86 m²/g) of StNPs prepared from enzymolysis is significantly larger than physical method StNPs. Therefore, theses nanoparticles are used for drug delivery of curcumin (CUR) to MCF-7 cell-lines. In case of CUR loaded StNPs, cell viability is affected about 51% and in presence of StNPs 40%. Both StNPs and CUR loaded StNPs are observed as a good antimicrobial agent. MIC values of StNPs and CUR loaded StNPs values are 60 µg/ml and 20 µg/ml respectively.

Graphical abstract

This study provides a comprehensive investigation into the enhancement of mechanical and thermal properties of epoxy polymer composites through the incorporation of magnesium layered double hydroxide (MH) and graphene nanoplatelets (GNP), highlighting their potential for advanced structural and functional applications. Various mechanical tests including tensile, compression, flexural, and impact were conducted with MH filler loadings ranging from 3, 6 and 9 wt% with 0.5 wt% of GNP. The test results showed that the 9 wt% of MH addition with 0.5 wt% of GNP yielded the high values of flexural and impact strength as 288.78 MPa and 0.1894 J/mm² respectively whereas maximum tensile strength of 101.55 MPa is exhibited by 6 wt% MH added composite. Thermal gravimetric analysis and dynamic mechanical behavior were employed to evaluate the thermal and dynamic behavior of the composite. The results indicate that the combined effect of selected fillers improves the thermal stability of the composites. MH enhances the thermal stability, with a linear improvement correlating with the wt% of MH and an increase in residual weight from 30.97 to 43.97%. DMA results confirmed the enhanced damping properties for GFREP with the addition of MH and GNP fillers. These results highlight the potential of MH and GNP added GFREP for high-performance applications requiring superior mechanical and thermal stability.

In this study, to address the issues of uneven dispersion and fracture damage of glass fibers (GF) during the preparation of traditional polyamide-based GF composites, a PA9T prepolymer (molecular weight: 2200; relative viscosity: 1.04) was innovatively adopted as the matrix. PA9T/GF composites were then fabricated by combining three-screw extrusion with melt viscosity-enhanced in-situ polymerization technology. Compared with finished polyamides, the low melt viscosity of the PA9T prepolymer provides a low-shear-stress dispersion environment for GF, which effectively maintains the consistency of fiber aspect ratio—fiber length concentrates in the range of 1.75–3.25 mm even at high screw speeds. By regulating the screw rotation speed (50–100 r/min) and feeding rate (2.0–3.0 Hz), uniform dispersion and interfacial compatibility of GF in the PA9T matrix were achieved. The results show that the composite prepared via this process exhibits a maximum tensile strength of 213.5 MPa and bending strength of 268.4 MPa, and the performance retention rate exceeds 84% after 2000 h of thermo-oxidative aging at 180 ℃. Additionally, it demonstrates excellent fatigue life (achieving 88.2 × 10⁴ cycles under a stress of 70 MPa) and creep resistance (exhibiting only 3.653% strain under a 90 MPa load for 1000 h). This study provides a new path for the preparation of high-performance polyamide-based composites based on prepolymer melt viscosity enhancement in-situ polymerization.

In this study, fluorine-free Si-based polyurethane (Si-PU) membranes were prepared via electrospinning. The electrospinning parameters were optimized in the presence of sodium chloride (NaCl) as an electrolyte, thereby affecting jet formation, stability, and nanofiber fineness. Four different amounts of Si nanoparticles (SNPs) (0.5, 1, 1.5, and 2 wt% in relation to PU) were dispersed in the polymer solution, and the effect on the static water contact angle, water vapor transfer, and the mechanical properties of the membranes was investigated. The results indicated that under the applied condition, 2 wt% of SNPs resulted in the highest hydrophobicity (105 ± 9°), appropriate breathability (2100 ± 68 g m^− 2 day^− 1), and the least fiber diameter (232 ± 57 nm). The fibrous membrane obtained from PU, NaCl, and SNPs could be a promising candidate for various applications including protective clothing, sportswear and etc.

This study explores the impact of using maleated PBAT (PBAT-g-MA) as a compatibilizer on the thermal and mechanical characteristics of composites made from polybutylene adipate-co-terephthalate (PBAT), Palm Fronds (PF) and Palm Stearin (PS). The issue arises from the use of single-use plastics which is non-biodegradable and raises concern for the environment. Additionally, the insufficient use of OPF PS, and PBAT-g-MA restricts the potential benefits they could offer. The research aims to improve the thermal and mechanical properties of PBAT/PF/PS blend by using PBAT-g-MA which includes enhancing the tensile strength, elongation, and thermal stability of the composite. In this research, a biodegradable composite blend was created by blending PBAT with PF and PS as a filler and subsequently incorporating PBAT-g-MA as a compatibilizer. The PBAT, PF, PS and PBAT-g-MA mixture was melted using an internal mixer. The result indicates that adding PBAT-g-MA significantly improved tensile strength and elongation at break, while reducing Young’s modulus. Thermal analysis showed a slight reduction in initial thermal stability with increasing PBAT-g-MA but demonstrated more uniform thermal degradation. Thus, these findings show that PBAT-g-MA can be an effective compatibilizer to enhance the mechanical and thermal properties of PBAT/PF/PS composites.