Journal of Polymer Research最新文献

The timber industry yields substantial amount of sawdust which acts as a source of pollution without proper management. One of the possible applications of the waste material is in using it as a reinforcing filler in biopolymer composites and thereby fostering the circular economy. However, the brittle nature of such material creates hinderance in its mass production and prevents its widespread commercial use. To address the shortcoming, this study explored the novel application of silly putty as a plasticizing additive in polylactic acid (PLA)-sawdust based composites. The addition of 5 wt% silly putty to PLA significantly increased the blend and the composite’s elongation at break by up to 280% and 100% respectively in comparison to PLA. Compared to the PLA/sawdust composite, PLA/silly putty/sawdust composite exhibited fewer voids and irregularities on the fracture surface. The surface roughness for the PLA/silly putty/sawdust composite reduced to 36.8 nm compared to 185.8 nm for PLA/sawdust composite. The improved surface finish of an extruded material is critical for its functionality and aesthetics. The water contact-angle of the novel composite increased to 76.5° from 68.4° of native PLA/sawdust composite. Biocompatibility assays revealed that the developed product is not cytotoxic and, therefore, it is not expected to be hazardous upon exposure.

A novel pH-responsive film has been developed utilizing polyvinyl alcohol modified with agarose (PA) as the film substrate and Clitoria ternatea L. extract (CTE) as the pH indicator through a casting process. The dose-dependent effects of CTE on the morphological, structural, mechanical, and barrier properties, along with its pH response sensitivity, are observed. The PA-CTE-7.5 film demonstrates the best fracture resistance (15.99 MPa), elongation at break (157.08%), and the minimum water vapor permeability (4.55(:times:)10⁻¹⁰ g/m.s.Pa) among formulations. The enhanced fracture strength and water resistance are attributed to the hydrogen bonding interaction between anthocyanins and the film matrix, as confirmed by ATR-FTIR. Concurrently, the PA-CTE-7.5 film reveals a counterbalancing color response, which is less efficient and stable than the PA-CTE-5. Additionally, the application of these pH-sensitive films to control shrimp freshness was assessed. The outcome shows the noticeable visual color changes of PA-CTE-5 film during shrimp spoilage, highlighting its great potential as an eco-friendly indicator for food freshness.

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This study investigates the mechanical and interfacial performance of Curaua fiber/epoxy composites reinforced with chestnut shell-derived biochar (CNB) and alkaline microfillers (CNM). The fillers were comprehensively characterized using FTIR, XPS, XRD, TGA, UV–Vis, SEM–EDX, particle size, and surface roughness analyses to elucidate their structural, chemical, thermal, and morphological properties. Composite panels were fabricated by incorporating CNB or CNM at various concentrations (2.5–10 wt. %) along with alkali-treated curaua fibers. The mechanical properties, including the tensile, flexural, impact, shear strength, and Shore D hardness, were evaluated. The results revealed that the incorporation of both fillers significantly enhanced the mechanical performance, with CNM-based composites exhibiting superior tensile and shear strengths owing to the improved interfacial adhesion and uniform dispersion of the fillers. In contrast, CNB-reinforced composites exhibited higher flexural strength and hardness owing to the intrinsic rigidity and partial graphitization of biochar. The optimal filler loading was identified be 7.5 wt. % for both CNM (CC3) and CNB (CCB3) based on the balance of mechanical properties. SEM analysis confirmed homogeneous dispersion and effective fiber–matrix bonding at this loading, whereas higher filler contents led to agglomeration and the formation of structural defects. The Preference Selection Index (PSI)-VIKOR multi-criteria decision-making approach ranked CC3 as the best-performing formulation, offering the highest overall mechanical properties. This study demonstrates the potential of valorizing chestnut shell waste as an eco-friendly filler for the development of high-performance sustainable hybrid composites for diverse engineering applications.

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.

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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.