Journal of Polymer Research最新文献

This study explores the influence of graphene oxide (GO) on the curing kinetics, mechanical properties, abrasion resistance, and swelling behavior of ethylene propylene diene monomer/acrylonitrile butadiene rubber (EPNBR) composites. These composites were fabricated via melt blending using an open mill mixer. The incorporation of GO led to increased minimum torque, maximum torque, delta torque, and cure rate index, while reducing scorch time and optimizing cure time in EPNBR composites. Tensile strength and stress at 100% elongation improved with GO addition up to 5 phr, beyond which they started to decline. However, GO negatively impacted elongation at break and rebound resilience. Notably, swelling resistance and abrasion resistance significantly improved with GO incorporation. Field Emission Scanning Electron Microscopy (FESEM) images of fractured surfaces confirmed the uniform dispersion of GO within the polymer matrix. The composites demonstrated tensile strength, tear strength, stress at 100% elongation, and abrasion resistance increases of 61%, 71%, 36%, and 17%, respectively. Conversely, elongation at break and rebound resilience decreased by 27% and 23%, respectively, compared to the base vulcanizates.

To address the challenge of controllable and precise regulation of the phase behavior of block copolymers, this study proposes a novel strategy to regulate the self-organization behavior of PS-P2VP block copolymers through supramolecular self-assembly. PS-P2VP was synthesized via the RAFT method, and three POSS molecules with different non-covalent interactions were synthesized and used to form complexes with the PS-P2VP copolymers. Characterization techniques such as NMR, GPC, FT-IR, TGA, DSC, SAXS, and SEM, along with theoretical methods, were employed to analyze the impact of POSS on the phase behavior of PS-P2VP. The results demonstrate that POSS is particularly effective in modulating the self-assembled phase behavior in the lamellar phase of block copolymers, with BPOSS-Cl showing the most significant modulation, enabling the complexes to achieve third-order peaks in SAXS measurements. This conclusion is further supported by theoretical calculations. The study not only reveals the mechanism by which POSS regulates the self-assembly behavior of PS-P2VP but also provides a promising direction for advancing autonomous phase selection in block copolymers.

In this work, we present the synthesis of polymethyl methacrylate (PMMA)-zeolite composite membranes for hemodialysis applications, using the non-solvent induced phase separation (NIPS) technique. The thermodynamic behavior of the NIPS process was investigated by measuring the cloud points of the PMMA/DMF/water and PMMAZx /DMF/water ternary systems. Additionally, attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the obtained materials. A staining method was also performed to observe the interaction between the membranes and electrolytes, followed by the measurement of the corresponding electrolyte flux. Subsequently, the membrane surface was modified using the Layer-by-Layer (LbL) assembly technique, with PDADMAC and heparin selected as the two electrolytes. The results demonstrate that PMMA-zeolite membranes exhibit new morphologies and improved properties compared to membranes made from a pure PMMA matrix.

Phase change materials (PCMs) represent a pivotal strategy for advancing energy recycling and sustainable development. Nevertheless, practical applications of PCMs are constrained by leakage risks, high rigidity, and low flexibility, which collectively limit their broader applicability. Therefore, developing PCMs with excellent thermal storage capacity and high flexibility is essential. In this study, a flexible crosslinked waterborne polyurethane-acrylate phase change composite was successfully prepared by selecting polyethylene glycol (PEG) as the soft segment material and trimethylolpropane (TMP) and hydroxyethyl acrylate (HEMA) as the modifiers. The impact of the molecular weight and incorporation quantity of PEG and the TMP concentration on the phase change characteristics and microstructure of the flexible phase change material was examined through the utilization of analytical techniques, including Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The experimental results demonstrate that the prepared flexible aqueous polyurethane-acrylate phase change materials exhibit good thermal storage capacity (the enthalpy of phase change is 125.6 J/g, along with favorable thermal stability and flexibility, which presents a potential for their utilization in the domains of energy storage and temperature regulation.

Most acrylate latex pressure-sensitive adhesives (PSAs) possess very low shear strength under high temperature environment and will leave a large amount of adhesive residue on the surface of the adherend when they are peeled off. To improve its heat-resistant adhesion performance, reactive anionic/nonionic surfactants SL- 900/ER- 10 and a novel ethylene-urea ethyl methacrylate (UMA) monomer were utilized to prepare a series of acrylate latexes via seeded semi-continuous emulsion polymerization containing butyl acrylate, methacrylate, acrylic acid and 2-hydroxyethyl acrylate. The results showed that the particle size and its distribution of latexes prepared with SL- 900/ER- 10 were smaller and narrower compared to SDS/O- 10, respectively. The introduction of UMA monomer made the latex particle size and its distribution become larger. It was also found that gel content, glass transition temperature (T_g) and thermal stability of the PSA film were all increased with the using of reactive surfactants and UMA monomer. Besides, water contact angle of the latex film increased gradually when fully reactive surfactants were employed, while decreased with the increment in UMA content. Furthermore, the latex film with fully reactive surfactants exhibited obvious improvement on initial tack and shear strength at room temperature, while a slight decrease in peel strength. Especially, when UMA content was 4wt%, the temperature of PSAs film leaving no residue after 2 h treatment increased to 160℃. The shear strength at 150 °C increased significantly and a balanced adhesion performance among initial tack, peel strength, and shear strength at high temperature was obtained by fully using reactive surfactants and UMA monomer.

The goal of this study was to develop a low-cost and eco-friendly fertilizer with slow-release properties for sustainable agriculture. This research presents the development of a new slow-release fertilizer (SRF) by dispersing a commercial NPK-based compound in a starch/polyacrylamide/graphene oxide (ST/PAM/GO) matrix. Six different formulations of ST/PAM/GO-NPK SRFs were prepared using a simple mixing-forming-drying technique, varying the NPK loading levels from 10 to 90 wt.%. Characterization tests revealed the influence of several factors on the SRFs'performance, including swelling, mechanical resistance, and the release rate of nitrogen, phosphorus, and potassium nutrients in water. These factors include the composition of the SRFs (NPK/polymer matrix ratio and the presence of graphene oxide nanofiller) and probable interactions between functional groups of each SRF component, which were investigated by FTIR structural analysis. The porosity of the SRFs was studied using SEM analysis. Finally, the release mechanism of the developed SRFs was examined using various mathematical modeling tools. The Korsmeyer-Peppas model was found to describe the release profile of the SRFs, indicating that the release occurs through a swelling-diffusion mechanism dominated by a relaxation phenomenon. This work offers a sustainable approach to fertilizer development by utilizing biodegradable and renewable materials, such as starch and polyacrylamide, combined with graphene oxide to enhance performance. The findings contribute to the polymer community by demonstrating the potential of polymer-based nanocomposites in controlled-release applications, providing a foundation for future research in sustainable agricultural practices.

Graphical Abstract

Waterborne polyurethane (WPU) resins have gained significant interest across various fields of industrial applications due to their unique features such as better adhesion to all types of substrates, lower emission of volatile organic compounds (VOC) and less environmental problems than solvent-based products. A cationic waterborne polyurethane elastomer based on poly(tetrahydrofuran-co-epichlorohydrine) (poly(THF-co-ECH)) has been synthesized with excellent mechanical, thermal and film forming properties. The poly(THF-co-ECH) was prepared through cationic ring opening polymerization of tetrahydrofuran (THF) with epichlorohydrin (ECH) and an acid catalyst. The WPU was prepared through prepolymer technique by using N-methyl diethanolamine as a hydrophilic chain extender. The WPU synthesized with optimum composition formed a stable dispersion with average particle size of 105 nm. Fourier-transformed infrared (FT-IR) spectroscopy, thermal analyses, dynamic light scattering (DLS), scanning electron microscopy (SEM) and tensile test were utilized to characterize the structure and investigate the properties of the both dispersion and polyurethane casted film. The results revealed that the casted film of the prepared WPU has elastomeric properties and has the potential to be used for coating applications.

Highly porous electrospun poly (lactic acid) (PLA) fibers were fabricated using a non-solvent induced phase separation (NIPS) mechanism, utilizing chloroform (CHL) as the good solvent and dimethyl formamide (DMF), dimethyl acetamide (DMAc), dimethyl sulfoxide (DMSO), and N, N- dimethyl pyrrolidone (NMP) as non-solvents. Optimal porosity was obtained with the DMF and DMAc systems, producing bead-free fibers with an average fiber diameter of 1–2 μm. Curcumin (Cur) was incorporated into both porous and non-porous PLA fibers. The porous and non-porous PLA/Cur composite membranes were characterized using FESEM, FTIR, XRD, TGA, DSC, tensile test (UTM), water contact angle measurement, water vapor transmission rate (WVTR) and cumulative curcumin release. The porous PLA/Cur membranes exhibited enhanced thermal stability, tensile strength, and water vapor transmission, along with a slower and, sustained release of curcumin, making them suitable for drug delivery, food packaging, sensing, and other environmental applications.

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This study explored the synergistic interaction of SiO₂ NPs and Welan gum for offshore application. Interaction characteristics, rheological behavior, Fluid-rock interaction and oil displacement were evaluated. FTIR, SEM and H-NMR were employed to characterize the SiO₂-Welan gum solution. The results showed that SiO₂ interacts with Welan gum through chemical bonds and possible hydrogen bonds due to hydroxyl group formation, increasing polymer roughness and causing network disruption. The incorporation of SiO₂ NPs into welan gum resulted in a viscosity enhancement of up to 50% at 1.5 wt% salinity, demonstrating significant stability improvement. SiO₂ NPs contribute to the thermal resistance of the polymer at elevated temperatures. Their synergistic effect was to mitigate salinity-induced viscosity reduction, maintaining fluid consistency more effectively than in the absence of nanoparticles. With SiO₂, the adsorption between polymer and limestone decreased over time, showing an average reduction of 19%. The adsorption was homogeneous and was best described by the Langmuir isotherm model. The oil recovery improved by 15% more efficiently than the welan gum alone. The study suggests that SiO₂ interacts with Welan gum in the ionic solution creating a three-dimensional network that resists conformational collapse and controls the polymer diffusion in limestone porous media.

Isotactic polypropylene (iPP) has emerged as a promising insulating material owing to its exceptional dielectric properties, recyclability, and processability. However, its semicrystalline nature leads to a complex biphase structure (crystalline and amorphous phases), in which disparities between the two phases critically influence electrical insulation and mechanical performance. This study aims to elucidate the intrinsic relationship between the biphase structure of iPP (regulated by crystallization conditions) and its properties, providing theoretical insights for optimizing dielectric and mechanical performance without introducing foreign additives. By adjusting crystallization temperatures (T_c​), five iPP samples with distinct biphase structures were prepared. Structural characterization techniques—including DSC, WAXD, and SEM—revealed that increasing T_c​​ enlarged spherulite sizes (from 32–104 μm) while maintaining constant crystallinity (~ 48–49%) and lamellar thickness (~ 17.6–17.8 nm). Dynamic mechanical analysis (DMA) quantified phase disparities (ΔT_{α2​−β​}, from 127.0 to 138.3 °C), which intensified interfacial electric field distortions and reduced dielectric breakdown strength (93 to 42 MV/m). Finite element simulations (COMSOL) confirmed higher ΔTα2​ − β​ amplified electric field inhomogeneity at phase boundaries. Uniaxial stretching tests at 25 °C and 140 °C demonstrated that increased biphase disparity weakened spherulite boundaries, lowering yield stress (37.0 to 31.0 MPa at 25 °C) and elongation at break (1207% to 20% at 25 °C). This study investigated the relationship between the biphase structure of iPP and its electrical insulation and mechanical properties. It provides valuable theoretical insights for manufacturing high-voltage cable insulation and energy storage devices such as capacitors, where enhanced dielectric stability is crucial.