An excessive intake of high-fat foods may pose a threat to human health. Oleogelation provides a promising strategy to reduce trans and saturated fatty acids in solid fats. Compared with small-molecule gelators, macromolecular gelators, particularly proteins, polysaccharides and their complexes are more suitable for this purpose. In this review, we systematically discuss the development potential of biopolymer-based oleogels. First, we elaborate the application of proteins, polysaccharides and their complexes as gelling agents. Second, despite the inherent hydrophilicity of these biopolymers, significant progress has been made in developing various preparation approaches, ranging from indirect templating strategies to direct dispersion methods. Third, we briefly discuss the underlying structuring mechanisms of these oleogels. Subsequently, we review their applications as fat replacers in specific food products. Finally, we present the conclusions and remaining challenges in this field. We aim to provide valuable insights into the utilization of biopolymer-based oleogels in the food industry.
Pyrolytic carbon black (CBp) and graphene oxide (GO) are commonly used to reinforce polymer matrices; however, their tendency to agglomerate limits composite performance. Conventional dual filler systems are frequently costly and challenging to scale. We exploited synergistic CBp-GO interactions to suppress agglomeration and establish a stable filler network, thereby improving the mechanical and electrical properties of natural rubber (NR) composites. Composites were prepared by blending CBp (40 phr) with GO at 0-8 phr. Filler dispersion was characterized by scanning electron microscopy and a carbon black dispersibility tester. Mechanical, vulcanization, and electrical properties were measured. At an optimal CBp/GO ratio of 40:4, a continuous filler network formed, reducing volume resistivity by eight orders of magnitude relative to CBp-only composites and by three orders relative to composites containing 2 phr GO. The 300% modulus increased by 18.3%, and the electrical percolation threshold decreased by 22%. Excess GO (>4 phr) induced agglomeration and reduced tensile strength by 16.4%. A key innovation is the use of CBp in constructing a low-cost multi-filler system that suppresses GO agglomeration without chemical modification. This approach provides a sustainable route to producing highperformance rubber composites and promotes the recycling of waste rubber.
We investigated the effectiveness of plant-based bio-additives - rhubarb, lingonberry, and blueberry (0.1-1%) - as natural UV absorbers in biodegradable polymers polylactide (PLA) and polycaprolactone (PCL). A novelty of this work is the direct use of plant-based raw materials as UV absorbers in polymers. We performed Fourier transformed infrared spectroscopy (FT-IR) and UV-Vis analysis of the bio-additives, determined the ultraviolet protection factor (UPF) for the polymer samples, and evaluated their physicochemical properties (structural changes, colour, hardness, surface energy) after weathering (PLA) and thermo-oxidative (PCL) aging. Spectroscopic tests confirmed the presence of UV-A/UV-B-absorbing chromophores in the additives. Samples with 1% berries had excellent UV protection (UPF 40-50+), while PLA and PCL containing 1% rhubarb had lower UPF values (around 22), indicating good UV blocking properties. After aging, PLA-containing berries showed a significantly lower carbonyl index (CI), indicating reduced photodegradation. For PCL with lingonberry, this additive gave the greatest reduction in thermo-oxidative degradation (lowest CI). All plant additives increased material hardness by acting as nucleating agents; they increased the crystallinity of polyester, and aging further strengthened this effect. Bio-additives, especially berries, can increase the hardness and UV resistance of polymers and limit material aging. These polymer compositions are suitable for packaging materials.
Polymethyl methacrylate (PMMA) remains the material of choice for denture base fabrication; however, its relatively low flexural and impact strength predisposes dentures to fracture during function and accidental loading. Various reinforcement strategies, particularly metal oxide nanoparticles and glass fibres, have been investigated in vitro, although comparative evidence remains limited and methodologically heterogeneous. This systematic review critically compared the effects of zirconium oxide (ZrO2) and titanium oxide (TiO2) nanoparticles versus glass fiber reinforcement on the flexural and impact strength of PMMA denture base resins. The review was conducted in accordance with PRISMA 2020 guidelines and a systematic search of PubMed, Scopus, EBSCOhost, and Google Scholar identified eligible in vitro studies published between 2014 and 2024. Five studies met the inclusion criteria. Glass fiber reinforcement consistently demonstrated the greatest improvement in flexural and impact strength, with progressive enhancements reported up to approximately 7 wt%fiber content. Among nanoparticle reinforcements, ZrO2 showed superior mechanical performance compared with TiO2, with optimal reinforcement observed at concentrations around 3 wt%, while higher concentrations were associated with reduced strength due to particle agglomeration and poor dispersion. Considerable heterogeneity was observed across studies in terms of PMMA type, reinforcement concentration, specimen preparation and mechanical testing protocols, precluding meta-analysis. Overall, the available in vitro evidence indicates that glass fiber reinforcement provides the most reliable mechanical enhancement of PMMA denture base resins, whereas nanoparticle-based reinforcement offers benefits only within narrow concentration ranges, underscoring the need for standardized methodologies and clinically relevant testing in future research.
Conventional poly(ethylene terephthalate) (PET) and polycarbonate (PC) blends exhibit insufficient heat resistance, restricting their use in demanding applications such as new energy vehicles and portable consumer electronics. Poly(ethylene 2,6-naphthalate) (PEN) offers superior thermal stability, strength and chemical resistance, making PEN/PC blends promising alternatives. In this study, we investigated the relationships between the composition, structure and properties of PEN/PC blends through non-catalyzed melt blending. Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance spectra (1H NMR) confirm transesterification between PEN and PC, with the extent of exchange (X) increasing with PC content. Non-isothermal differential scanning calorimetry (DSC) and X-ray diffraction (XRD) show that moderate PC content promotes crystallization, while high PC content suppresses it. Thermogravimetric analysis (TGA) shows enhanced thermal stability in PEN-rich blends. Compared to PET/PC, PEN/PC blends maintain similar tensile strength but exhibit 53% higher elongation and 1-2.5% lower density. This study demonstrates the potential of PEN/PC blends for high-performance, thin-walled applications in the new energy vehicle and electronics industries.
We investigated the possibility of applying rejected natural rubber gloves (RNRGs) as a matrix for rubber composites filled with sepiolite. The virgin natural rubber (NR) samples were also prepared for comparison. Clearly, the RNRGs can be re-mixed with rubber chemicals, re-shaped, and revulcanized. Maximum torque increased with sepiolite loading during vulcanization, along with stress at 100 and 300% strains and strain-induced crystallization ability, whereas the tensile strength and elongation at break of the RNRG composites exhibited an opposite trend. The unfilled RNRG possessed high tensile strength (similar to 19.86 MPa) and extensibility (similar to 600%), which was about 67% higher than that of the unfilled NR sample. However, increased sepiolite loading decreased the thermomechanical properties of the RNRG composites because the RNRG had undergone vulcanization before re-mixing and revulcanizing; the NR-based composite showed the opposite trend. Based on the results, the RNRGs can be re-used as the rubber matrix of rubber compounds when thermal properties are not critical.
Enhancing the interfacial bonding performance between carbon fibers (CF) and thermoplastic resins is extensively researched. In this study, we propose a novel method for the synergistic surface modification of carbon fibers using a silane coupling agent and poly-carbonate diol (PCDL), which significantly improves the interfacial compatibility between CF and polycarbonate (PC). Scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) confirmed the successful grafting of silane onto the surface of CF and subsequent PCDL sizing. Mechanical characterization showed that the modified carbon fiber composites exhibited a 47.3% increase in interlaminar shear strength (ILSS) relative to the unmodified system. Notably, with a loading of 10 wt%, the modified fibers improved the tensile strength, flexural strength, and notched impact toughness by 36.2, 38.5, and 39.6%, respectively. The impact fracture surfaces exhibited typical characteristics of ductile fracture, with a dense and gap-free interfacial layer forming between the fiber and the matrix, indicating that the efficiency of stress transfer was effectively enhanced. The findings of this study are expected to provide a valuable technical reference for the fabrication of carbon fiber-reinforced thermoplastic composites.
In this study, we present an effective chemo-enzymatic method for synthesizing di- and tetra-carboxyl-functionalized poly(ethylene glycol)s (PEGs) using Candida antarctica lipase B (CALB). PEG-diacid was synthesized through CALB-catalyzed Michael addition of 3-mercaptopropionic acid (3-MPA) to PEG-diacrylate. We found that the reactions proceeded in a stepwise manner, first producing monoacid. The synthesis of diacid required additional fresh CALB and 3-MPA. The structure of the products was confirmed by 800 MHz 1H NMR. PEG-tetraacid was synthesized in a single step via CALB-catalyzed Michael addition of acrylic acid to PEG-diamine. In both cases, the CALB-Catalyzed Michael addition reactions effectively produced carboxyl-functionalized PEGs.
We used dynamic mechanical analysis (DMA) to evaluate soy flour adhesives made with and without a conventional crosslinking agent, polyamideamine-epichlorohydrin (PAE). Fixed-frequency and constant strain rate studies revealed that PAE contributes to a decrease in glass transition temperature (Tg), an increase in toughness, and a decrease in both the rubbery plateau modulus and onset temperature, consistent with plasticization. Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) studies of water-soluble extracts from pre-cured soy flour revealed the presence of polypeptides with exchangeable protons, carbohydrates, citric acid and lactic acid. Deuterium exchange studies showed that the protonated peptides were no longer water-soluble after cure. Instead, post-cure extracts contained heat-modified carbohydrates and carboxylic acids, together with adipic acid when PAE was employed. These results are consistent with a mechanism whereby PAE not only undergoes hydrolysis and chain scission, but also competitively co-reacts with peptides and carboxylic acids to yield a plasticized chain-extended network with decreased crosslink density, counter to its anticipated function. The implications of these findings as they pertain to moisture resistance and wood adhesion will be discussed.
This study reports the fabrication and evaluation of layered scaffolds based on polylactide/polycaprolactone (PLPC) matrices for osteochondral-inspired designs. Bilayer architectures comprised a bone-facing layer with mineral phase (PLPC containing hydroxyapatite, HAP) and a cartilage-facing layer (PLPC containing only glucosamine sulfate (GS) or with simultaneous use of GS and an integrated electrospun gelatin/chondroitin sulfate (GEL/CS) fabric). The scaffolds exhibited interconnected porosity (55-60%) with a pore-size gradient (5-250 mu m). Mechanical testing showed compressive strength up to 1 MPa and a layer-dependent compressive modulus, remaining within ranges reported for osteochondral tissues after six weeks of incubation. The layered configuration provided controlled GS release and reduced incubation-induced acidification; FTIR/XRD confirmed apatite precipitation in phosphate-buffered saline (PBS), enhanced when the GEL/CS fabric was present. After incubation, surface wettability shifted toward increased hydrophilicity, and permeability was modulated by scaffold composition, indicating tunable fluid-transport behavior. Overall, spatial separation of additives combined with a fibrous GEL/CS modifier enables control over mechanical response, release/medium evolution during incubation, and in vitro apatite-forming ability in PBS in a bilayer PLPC scaffold system.
The increasing release of greenhouse gases (GHGs), particularly CO2, continues to drive global warming and highlights the need for effective mitigation technologies. In this study, porous nanostructured cellulose acetate (CA) fibrous mats were fabricated via electrospinning and integrated with natural clinoptilolite (CLN) and synthetic ZSM-5 zeolites to improve CO2 capture. Physicochemical characterization, elemental analysis, FTIR, XRD, SEM-EDS, and TGA confirmed the incorporation of zeolitic fillers and revealed their influence on fiber structure and thermal stability. We conducted CO2 adsorption and H2/CO2 permeability tests to assess the feasibility of the electrospun fibrous mats for pre-combustion hydrogen purification. CA/ZSM-5 fibrous mats showed enhanced fiber uniformity, improved thermal stability, and superior CO2 adsorption and H2 separation performance, whereas CA/CLN fibrous mats exhibited good CO2 capture but limited hydrogen selectivity. These results demonstrate that zeolite type governs the structural and functional behavior of electrospun CA hybrid fibrous mats, offering insights for developing sustainable materials for gas separation.
Conventional sulfur vulcanization in rubber manufacturing depends on elevated curing temperatures and zinc oxide activators, resulting in high energy consumption and increasing environmental concerns associated with zinc release. To overcome these limitations, a novel graphene oxide (GO)-supported rare-earth-containing accelerator (GO-LZC) was designed by coordinating lanthanum(III) and zinc(II) ions with sodium diethyldithiocarbamate (DC). At the same time, the oxygen-containing groups on GO further participated in ligand coordination. The resulting GO-immobilized complex exhibits a well-defined chelating structure and uniform nanoscale dispersion, which together enhance the accessibility and reactivity of active sulfurating species during curing. When incorporated into solution-polymerized styrene-butadiene rubber (SSBR), GO-LZC markedly promotes crosslink formation at reduced thermal input. Kinetic analysis reveals a substantial decrease in the apparent activation energy, and curing and mechanical tests confirm that efficient vulcanization can be achieved at 130 degrees C, representing a 20-40 degrees C reduction relative to typical industrial curing conditions. This work demonstrates a viable strategy for developing low-zinc, energy-efficient, and high-performance vulcanization systems. It highlights the potential of rare-earth/GO hybrid catalysts for sustainable rubber processing.
This work presents the development of high-performance thermoplastic polyurethane (TPU) nanocomposites reinforced with low contents of multilayer graphene (mG), aiming to improve their tribological behavior. Using twin-screw extrusion followed by hot pressing, nanocomposites containing 0.1, 0.25, 0.5, 1, and 2% mG weight were fabricated and systematically evaluated. Nanocomposites with only 0.1-0.25 wt% mG achieved a 36% reduction in friction coefficient and 87.5% reduction in wear volume compared to neat TPU. Results are rarely reported at such low filler loadings. Scanning electron microscopy (SEM) analysis revealed uniform dispersion at these optimal concentrations, while higher mG contents led to agglomeration and performance loss. Rheological studies indicated improved flow behavior, and dynamic-mechanical analysis confirmed increased energy dissipation and thermal response. These results suggest that the concentrations of 0.1% and 0.25% of multilayer graphene used in the study are promising for improving the performance of TPU nanocomposites in applications requiring high wear resistance for advanced applications in automotive, biomedical, and high-load engineering components, where durability and low friction are essential.
Growing interest in natural and eco-friendly materials has driven the search for sustainable alternatives to synthetic antimicrobial agents. This study aims to develop antibacterial fibers based on poly(vinyl alcohol) (PVA) reinforced with chitosan (CTS) using an environmentally friendly wet-spinning process. Morphological analysis revealed surface irregularities that increased with CTS content, confirming its effect on fiber microstructure. Thermal analyses by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) showed that CTS incorporation decreased the melting temperature while improving thermal stability. Mechanical testing demonstrated enhanced tensile strength (sigma s) and Young's modulus (E) due to strong intermolecular interactions between CTS and the PVA matrix. The highest sigma s (1045 MPa) was obtained at 3 wt% CTS, while E reached 7.1 GPa at 5 wt%. Antibacterial tests against Staphylococcus aureus and Escherichia coli confirmed strong activity attributed to -NH2 groups of CTS disrupting bacterial membranes. These results highlight the potential of PVA/CTS fibers for biomedical applications such as wound dressing and antibacterial materials.
Poly(lactic acid) (PLA) has attracted much attention and shows promising applications in numerous fields. In this study, PLA was plasticized using bio-based castor oil derivatives - hydrogenated castor oil (HCO) and castor oil glycidyl ether (COGE). These eco-blends were measured using a Fourier transform infrared spectrometer, a scanning electron microscope, a contact angle test, rheology, a differential scanning calorimeter, thermogravimetry, polarized optical microscopy, and a tensile test, respectively. The findings show that a core-shell morphology of COGE-HCO encapsulation is formed in PLA matrix, and the hydrogen bonding interaction and ring-opening chemical reaction among functional groups of the components greatly improve the compatibility, ductility, cold crystallization ability, and thermostability of the eco-blends, but the melt crystallization ability is hindered. The incorporation of HCO improves the hydrophobicity and oleophobicity of the eco-blends. Due to the combined effect of HCO and COGE, the melt viscosity reduces, and the Newtonian behavior enhances; the nucleation density and spherulitic growth of PLA increase. The strain at break of the PLA/HCO/COGE (90/7.5/2.5) blend reached 221%, which is 22.6 times higher than that of the neat PLA. These eco-blends present appropriate rheological, thermal, and mechanical properties, showing application scenarios in biodegradable packaging and disposable appliances.
To improve the toughness, thermal stability, and melt processability of polylactic acid (PLA), this study introduced chlorinated polyethylene-polyethylene glycol (CPE-PEG, 10 wt%) into the PLA matrix and investigated the effect of the content of nano-SiO2 surface-modified with the silane coupling agent KH570 (K-SiO2) on the composite properties. Composite filaments were prepared via single-screw extrusion, and standard specimens were printed using fused deposition modeling (FDM) technology. Comprehensive characterization indicated that the composite achieved optimal mechanical properties at a K-SiO2 content of 1.5 wt%; simultaneously, the material's thermal stability and crystallization behavior were optimized. Rheological behavior demonstrated that K-SiO2 could regulate the melt viscoelasticity, broadening the FDM processing window. This study provides an effective strategy for developing high-performance PLA composites for FDM printing.
Microfluidic and millifluidic systems are increasingly used for chemical and biological analysis. Thermoplastic polymers offer a practical alternative to glass and silicon. They are inexpensive, easy to shape, and suitable for disposable devices. However, most polymer microfluidic chips are still produced in two steps: machining the channels, then bonding a cover plate. This workflow increases alignment constraints, exposes open channels to contamination, and lengthens production time. This study presents a one-step method based on transmission laser welding (TLW) applied to closed-cell thermoplastic foams. The laser heats and collapses the foam locally, causing the cell walls to fuse and form a channel while welding a transparent cover at the same time. The process creates a sealed microchannel without moving the parts between steps. We examine the feasibility of this method and study how laser output power affects channel dimensions. The approach also enables the creation of X and Y junctions by using several fast passes to control melting at the intersections. The channels obtained show smooth internal walls and a near-cylindrical cross-section. Their size can be adjusted through the laser parameters. This method offers a simple and clean way to prototype polymer millifluidic or microfluidic devices.
