Journal of Applied Polymer Science最新文献

This study uses a polymer blend as a host polymer prepared by PEO and PVDF-HFP, with Li₇La₃Zr₂O₁₂ (C-LLZO) and Li_6.5La₃Zr_1.75Te_0.25O₁₂ (Te-LLZO) as ceramic fillers and lithium trifluoro methane sulfonate (LiCF₃SO₃) as a salt. Using the XRD and FTIR spectra, the impact of ceramic (C-LLZO and Te-LLZO) on enhancing the salt dissociation and cation coordination with oxygen atoms in PEO and fluorine atoms in PVDF-HFP has been investigated. Notable changes in ceramic peak intensity, peak position, and the existence of an amorphous hump in XRD spectra indicate an increased amorphous content with low ceramic loading. However, the crystallinity of the electrolyte increases with increasing ceramic loading. With different ceramic loading, the vibrational bands of CF₂ and COC have shifted and varied. It shows that ceramic loading has significantly impacted cation coordination with those peaks. Conversely, the enhanced ion dissociation with ceramic variation is established by the deconvolution of FTIR in the wavenumber region of 1020–1050 cm⁻¹. The free anion content is substantial at 20 wt% ceramic loading, according to FTIR measurements. It suggests a greater likelihood of available cations for coordination. The optimized polymer blend-salt-ceramic composite sample shows an excellent DC conductivity at room temperature of 0.613 × 10⁻³ Scm⁻¹. This is an enhancement of approximately two orders compared to the blend-salt system. Along with that, this optimized polymer blend composite shows excellent voltage stability of 5.90 V and thermal stability up to ~400°C. Furthermore, an EDLC device has been developed using the optimized composite electrolyte. It shows an impressive specific capacitance of 6.52 mF/g at a 10 mV/s scan rate.

To further enhance the comprehensive performance of polymer electrolytes, this study prepares a ternary composite gel polymer electrolyte (CGPE) based on TiO₂/thermoplastic polyurethane (TPU)/polydimethylsiloxane (PDMS) via a solution casting method, systematically investigating the influence of TiO₂ content on the properties of CGPE. Structural characterization reveals that TiO₂ nanoparticles achieve a “dual crystalline phase regulation” mechanism by inhibiting polymer crystallization and introducing anatase crystal phase. When the TiO₂ content is 9 wt%, the CGPE exhibits optimal performance: ionic conductivity reaches 4.59 × 10⁻³ S/cm, an 81.5% increase compared to the pure polymer matrix; tensile strength is 9.61 MPa, elongation at break is 449%; lithium ion transference number is 0.78; and the electrochemical stability window is 0–5.0 V versus Li/Li⁺. The assembled LiFePO₄/Li half-cell demonstrates a rate capability of 87.4% when the current density increases from 0.1 to 1 C, with 99.2% retention after 100 cycles. The results confirm the application potential of TiO₂-reinforced CGPE in high-safety lithium-ion batteries.

The electrolyte is an essential element of modern energy storage systems, guiding ion migration between electrodes. Sodium carboxymethyl cellulose (NaCMC) has emerged as a promising green alternative for electrolyte materials. The poly(vinyl alcohol)/NaCMC polymer network has gained popularity as a prominent polymer blend. PVA/NaCMC polymer blends loaded with sodium tungstate salt were prepared as PVA/NaCMC/Na₂WO₄ polymer blend nanocomposite electrolytes via a solution casting technique. FTIR analysis reveal shifts in band assignments related to OH and CO groups, suggesting Na⁺ interactions with polar functional groups in PVA and NaCMC, promoting salt dissociation and anion immobilization for efficient cation mobility. Tungstate anions, on the other hand, act as a pivotal nanofiller component that optimizes the polymer blend's microstructure and properties beyond mere ion supply. Tungstate anions disrupt the semi-crystalline nature of the PVA/NaCMC polymer blend, as confirmed by XRD patterns showing reduced crystallinity with increasing Na₂WO₄ salt concentration, which increases amorphous domains and free volume for enhanced ion pathways. This leads to improved thermal stability and electrochemical stability. Sodium ions, derived from both NaCMC and the dissociated Na₂WO₄ salt, serve as the primary mobile charge carriers responsible for ion transport. They facilitate conductivity through a hopping mechanism, where sodium ions migrate between coordination sites in the polymer matrix, particularly in amorphous regions, under an applied electric field. This is evidenced by the observed ionic conductivity of 5 × 10⁻⁶ S cm⁻¹ was recorded at room temperature for the PVA/NaCMC blend containing 10 wt% sodium tungstate salt, and rose to 4.4 × 10⁻⁴ S cm⁻¹ at 80°C. The temperature dependence of the conductivity followed Arrhenius behavior. An equivalent electric circuit model was used to interpret the EIS data. The dielectric properties were investigated by examining AC conductance spectra, dielectric constants (ε′ and ε″), electric moduli (M′ and M″), and loss tangents. The dielectric permittivity increased in the low-frequency region owing to electrode polarization effects. The maximum of the loss tangents shifted with increasing temperature, accompanied by an increase in peak height at high frequencies. Sodium-tungstate-based polymer blend nanocomposite electrolytes exhibited an enhanced electrochemical stability window (2.57 V), a higher transference number (0.973), and improved ionic conductivity, making them suitable for energy storage device applications.

In this study, Poly(o-anisidine)/dextran composite film was electrochemically synthesized on a platinum electrode using the cyclic voltammetry technique. Characterization of the synthesized composite film was conducted using FT-IR (Fourier transform infrared) analysis, UV–Vis (Ultraviolet–visible) spectroscopy, ¹H-NMR (nuclear magnetic resonance) spectroscopy, CV (cyclic voltammetry), and TG-DTG (thermogravimetric analysis-differential thermogravimetric analysis) techniques. Based on the spectroscopic analysis results, a possible chemical structure for the composite was proposed. The surface morphology of the composite film was examined using SEM (scanning electron microscope), which revealed that the composite film homogenously covered the surface of the platinum electrode. Solubility tests showed that the composite dissolved in common organic solvents, with DMSO (dimethyl sulfoxide) identified as the most effective. TG-DTG analysis showed that the composite film exhibited good thermal stability and distinct thermal behavior compared to the poly(o-anisidine) homopolymer. Furthermore, electrochemical studies demonstrated that the composite possessed high electrochemical stability, good redox behavior, and high electroactivity.

pH-responsive fertilizer is an innovative slow-release fertilizer that can regulate the release of nutrients according to changes in soil pH, which is designed to improve the applicability of fertilizers according to environmental changes during crop growth. It has research and development potential in the field of smart agriculture in the future. This study developed a starch-based pH-responsive hydrogel (SA) using starch (St) as the matrix and acrylic acid (AA) as the functional monomer, which was subsequently employed to encapsulate urea particles for controlled nutrient delivery. The effects of St/AA ratios and crosslinker concentrations on the hydrogel's water retention, absorption capacity, and swelling behavior were systematically investigated. The fertilizer's release kinetics were evaluated in both aqueous and soil environments, with particular emphasis on pH-dependent responsiveness. Experimental results demonstrated that under typical soil conditions (pH 7 and 9), formulations with St:AA = 3:1 and St:MBA = 500:1 exhibited optimal pH-responsive characteristics. These formulations achieved equilibrium cumulative nitrogen release rates of 80.43% and 80.51%, respectively, with sustained release durations extending to 30–35 days. The findings highlight the potential of starch-based pH-responsive hydrogels as effective carriers for smart fertilizer systems in precision agriculture applications.

Polyurethane foam (PUF), valued for its low density and exceptional mechanical performance, has found extensive industrial applications. However, escalating demand has resulted in substantial waste accumulation, posing urgent environmental concerns. Aligned with carbon neutrality objectives, this study proposes a sustainable strategy for recycling rigid PUF (R-PUF) waste through solid-state shear milling (S³M). The mechanochemical process successfully reduced the average particle size of R-PUF to 55.91 μm while inducing molecular chain motion, characterized by molecular chain recombination and increased surface roughness. The resultant polyurethane powder was functionalized with a silane coupling agent and reintroduced into polyol matrices, forming chemically crosslinked interfaces that enhanced composite performance. Systematic investigations revealed that milling cycles critically influenced surface functional groups and powder morphology, while optimal mechanical properties were achieved at 3 wt.% filler loading, increasing compressive strength from 1.2 to 1.3 MPa. Silane modification further amplified compressive strength by 80% (0.5 → 0.9 MPa) compared to untreated R-PUF and non-modified milled powders. These enhancements are attributed to the mechanochemical restoration of thermoplasticity and interfacial bonding via silane-mediated covalent linkages. This work establishes S³M as an eco-efficient methodology for transforming thermoset foam waste into high-value composites, advancing circular economy principles in polymer recycling.

To address challenges such as severe vertical etching, bottom water breakthrough, insufficient retardation, and high corrosivity associated with conventional acids in carbonate slit-hole reservoirs under high-temperature and high-pressure conditions, novel foam acid systems are developed using acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, methacryloyloxyethyl trimethyl ammonium chloride, and octadecyl ethoxylated methacrylate. Hydrophobically bonded thickening agents (HAT-1 and HAT-2) are synthesized via free-radical polymerization and combined with the surfactant O-25(fatty alcohol polyoxyethylene ether) to form foam acids. Fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy are employed for acid characterization. The involved microstructures, surface tension, temperature resistance, pressure resistance, retardation, and corrosion inhibition characteristics are also tested. The considered HAT-2-based foam acid has a half-life of 25 min at 140°C, maintains stability at 6–10 MPa, and exhibits a static-retardation rate of 94.86% and an acid–rock reaction rate of 2.09 × 10⁻⁶ mol/(cm²·s), demonstrating strong retardation performance. Its corrosion rate on N80-E steel is 6.462 g/m²·h. Notably, the stability and drainage resistance of this foam acid are ensured by a synergy between HAT-2–O-25 hydrophobic interactions and hydrogen bonding with water molecules. Overall, this system serves as a new and efficient foam acid for acidifying carbonate rock formations.

Thermoplastic polyurethane (TPU), with high strength and elasticity, is widely used in wind turbine blade protection. However, it struggles to resist particle erosion and UV aging in desert environments. In this study, UV-327 (A), UV-531 (B), and HALS622 (M) were combined to prepare UV-resistant UV-TPU/NW (ABM) film. The three anti-UV agents cover the main wavelengths, forming a three-dimensional protective network of “UV absorption, free radical scavenging, and cyclic regeneration.” ABM film shows tensile strength 39.71 MPa and elongation 935.48%, comparable to pure TPU (39.52 MPa, 939.58%). After 10 days of UV aging, the color difference (ΔE) and yellowness index (ΔYI) of ABM are 12.88 and 24.25, respectively, significantly lower than those of pure TPU (ΔE = 24.74, ΔYI = 47.69). After 20 days of UV aging, ABM film only has a few fine cracks on the surface, and the tensile strength and elongation at break remain at 31.50 MPa and 868.35%, respectively, much higher than those of pure TPU (17.66 MPa, 706.53%), with a low erosion rate of 1.52% (pure TPU 2.67%). Meanwhile, UV-TPU/(NW@G/C_1.0) electrothermal film based on ABM maintains a steady-state temperature of 81.16°C under 11 V after 20 days of aging. This demonstrates its potential for anti-icing applications on wind turbine blades.