Journal of Applied Polymer Science最新文献

To address premature failure of packer rubber seals in supercritical CO₂ injection wells, this study systematically investigated the effect of acrylonitrile (ACN) content (18%–40%) on the CO₂ resistance of nitrile rubber (NBR). Two material systems were evaluated: unfilled NBR and NBR/carbon black N550 (N550) composites with 50 phr carbon black. Performance under CO₂ conditions (100°C, 10 MPa, 72 h) was assessed through compression set, mass and volume changes, mechanical and tribological properties, and microstructural analysis, elucidating ACN-dependent structure–property relationships. For unfilled NBR, DN3350 with moderate ACN exhibited balanced tensile strength (1.9 MPa) and elongation (160%), achieving the lowest compression set (46.0%). In NBR/N550 composites, high-polarity DN4050/N550 (40% ACN) formed a dense filler–matrix network, enhancing anti-swelling behavior (volume change rate: 0.734%), maintaining superior mechanical performance (tensile strength: 23.6 MPa; elongation: 198%) and low coefficient of friction (0.72). FTIR and microscopic analyses confirmed that higher ACN strengthens intermolecular forces and filler compatibility, suppressing CO₂-induced microcracking and degradation. These findings provide a theoretical foundation for designing high-performance packer seals, highlighting DN4050/N550 as the optimal material for supercritical CO₂ environments.

This study pioneers a novel strategy for creating smart polymer composites by incorporating thermoplastic polyurethane (TPU) into a bitumen matrix, successfully integrating dual shape memory and autonomous self-healing functionalities. Comprehensive characterization confirms excellent polymer-matrix compatibility, with FT-IR spectroscopy revealing chemical interactions at the interface. The modification drastically improved the composite's performance: the softening point increased from 46.7°C to 60.2°C, and the tensile strength surged by over 120% at 20°C for the 8.0 wt.% blend. Rheological tests showed enhanced viscoelastic properties and resistance to high-temperature deformation. Remarkably, the composite achieved up to 81% shape recovery and a self-healing efficiency of 85%, quantitatively assessed via a beam on elastic foundation (BOEF) method. We elucidate a synergistic multi-scale healing mechanism where thermal stimulation triggers the TPU's shape memory effect to close cracks, thereby creating a conducive interface for intensive molecular diffusion and entanglement. This work validates a groundbreaking and generalizable polymer-based paradigm for developing next-generation smart composites with enhanced durability and multi-functionality for sustainable pavement applications.

The viscometric behavior of aqueous solutions of acrylamide and acrylamidopropyl trimethylammonium chloride copolymers (AM-co-APTMAC) with varying cationic content under different salinity conditions was studied. Viscometric measurements were employed to determine intrinsic viscosity and quantify the influence of electrostatic interactions on chain conformation. Rheology experiments were performed to probe dynamic flow behavior under shear to obtain insights into polyelectrolyte viscoelastic properties under conditions mimicking industrial processes. Viscometric and rheology data analysis is augmented with insights from NMR relaxation and pulsed field gradient NMR diffusion experiments. Further, flocculation of kaolin suspensions was studied using aqueous solutions of AM-co-APTMAC copolymers with different charge fractions in the presence and absence of salt. The physicochemical insights on the behavior of AM-co-APTMAC polyelectrolytes in solution from this study could be relevant in practical applications, such as plants that use seawater or in cases where the ionic strength of suspensions is high due to salinity in the medium.

Aramid fiber (AF)-reinforced composites face significant limitations in applications such as deep-sea equipment and aerospace due to their poor interfacial compatibility and low bonding strength. This study presents an innovative and scalable strategy for constructing a nano-hierarchical reinforcement interface on AF to fundamentally address this issue. A multifunctional interlayer was first constructed using polyethyleneimine (PEI) and polydopamine (PDA), on which both carboxylated and aminated carbon nanotubes (COOH-CNTs and NH₂-CNTs) were co-anchored to produce the final product, denoted as C/N-CNTs-PP-AF. The distinctive dual-CNT configuration produced a stable electrical resistance in the range of 51.57–84.20 MΩ by forming a continuous conductive network. More importantly, C/N-CNTs-PP-AF/unsaturated polyester (UP) composites exhibited significant enhancement in properties, which corresponded to an interfacial strength of 39.60 MPa (an 81.15% increase) and tensile strength of 1404.25 MPa (an 89.45% improvement). The approach leverages multifaceted interfacial interactions to enable stable CNT grafting and enhanced adhesion. This work not only effectively addresses weak bonding at the AF/UP interface but also establishes a new paradigm for the design of high-performance fiber-reinforced composites with integrated functionalities.

Polymeric binders play a critical role in composite solid propellants by firmly bonding all components, forming the matrix and skeleton, and enhancing toughness to maintain the propellants' structural integrity and mechanical properties. Therefore, developing energetic and tough binders is essential. Glycidyl azide polymer (GAP) is widely used in solid propellants, but its poor flexibility leads to a high glass transition temperature. Introducing fluorine into binders can improve thermal stability, optimize the oxygen balance of solid propellants, reduce oxidizer usage, enhance the utilization of energetic materials, and increase propellant energy. In this study, fluorinated polyether was grafted onto the side chains of GAP_1k via click chemistry to synthesize GAP_1k-g-F₃, which was then dual cured with a multifunctional alkyne-terminated curing agent and an isocyanate-based curing agent to prepare GAP_1k-g-F₃-PTU. The mechanical properties, thermal stability, and microstructure of the elastomers were characterized by uniaxial tensile testing, dynamic thermomechanical analysis, thermogravimetric analysis, and scanning electron microscopy.

Thermal interface material (TIM) is a critical polymer composite material, primarily valued for its adhesive properties and thermal conductivity. The thermal conductivity of TIMs can be further classified into vertical and horizontal directions, with the vertical thermal conductivity significantly influencing the overall heat transfer efficiency. In this study, we first synthesized an acrylic adhesive characterized by strong cohesion and high-temperature resistance. Subsequently, leveraging the spherical shape of alumina particles and controlling film thickness through coating techniques, we prepared a thermally conductive film featuring a unidirectional arrangement of alumina in the horizontal direction. This film leverages the pressure-sensitive properties of the adhesive, ensuring direct contact between alumina and both the heat source and the heat sink during practical application, thereby facilitating efficient heat dissipation. The simplicity of the preparation method underscores the significant potential applications of this thermally conductive film.

This article demonstrates the thermoelectric properties of ZnO nanorods (NRs)/poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) composites films on a flexible ITO substrate. Compact ZnO thin films and ZnO NRs have been grown by the cost-effective sol–gel method. The thermoelectric properties of both films have been investigated along with thermophysical characteristics. X-ray diffraction reveals the hexagonal wurtzite growth of ZnO nanostructures. The temperature-dependent thermal characteristics for both composites have been investigated through the transient plane source method in the temperature range of 303–353 K. The thermal conductivity of the compact ZnO/PEDOT:PSS composite is found to be in the range of 1.30–1.33 W/mK, whereas a significant enhancement in thermal conductivity is observed in the ZnO NRs/PEDOT:PSS composite film, which is attributed to phonon scattering and interfacial transport through vertically aligned nanorods. Compared with earlier ZnO-polymer composites reported in the literature, this work highlights the unique influence of ZnO NRs/PEDOT:PSS morphology on thermoelectric behavior in flexible films. Our study reveals that these composites could be beneficial for low-temperature waste heat management devices.

The inherent lipophilic nature of epoxy resin impedes its uniform dispersion in aqueous phases, thereby compromising hybridization efficacy. To address this, waterborne modification of epoxy resin is essential. Common strategies include self-emulsification and surfactant-assisted methods, with the latter being preferred for its simplicity and cost-effectiveness. In this study, the surfactant Triton X-405 (octylphenol ethoxylate) was employed alongside a phase inversion method to prepare an aqueous dispersion of epoxy resin (DER-331). This dispersion was subsequently hybridized with an acrylic emulsion synthesized via emulsion polymerization in an aqueous medium. Increasing the epoxy resin content elevates the solid epoxy content (SEC) of the hybrid system. Post-hybridization, a waterborne epoxy curing agent was incorporated to form cured coatings. The obtained coating exhibits significant improvements in physical properties. The dense network formed after the curing of epoxy resin and styrene-acrylate substantially enhances both the physical and anti-corrosion properties of the coating. When the epoxy resin content reaches 15% of the acrylic resin, the latex particle size distribution is the narrowest, and the mechanical properties of the cured coating are optimized: the hardness reaches H, flexibility is 0.5 mm, and adhesion reaches 1.21 MPa. Furthermore, the thermodynamic properties are improved compared to those of pure acrylic resin. The anti-corrosion performance is also significantly enhanced, with a corrosion current density (I _corr) of 6.9506 × 10⁻⁷ A/cm² and a corrosion potential (E _corr) of −0.2291 V, demonstrating excellent corrosion resistance.

A novel, industry-oriented strategy was developed to enhance flame retardancy in polyester fibers through a zinc phosphinate-based masterbatch. The masterbatch was prepared via twin-screw extrusion using 20 wt% Exolit OP950 and high-viscosity bottle-grade PET granules, selected to mitigate molecular degradation and preserve rheological integrity during melt-spinning. It was subsequently incorporated into virgin fiber-grade PET at 3%, 5%, and 7 wt% concentrations to produce flame-retardant fibers. Rheological evaluations revealed pronounced shear-thinning behavior and increased elasticity with higher flame retardant (FR) loading, indicating improved melt strength and viscoelastic stability. Thermal analyses demonstrated enhanced char formation and reduced heat release, with residual carbon content rising from 5.7% in neat PET to 10.7% in the 7% FR sample. The limiting oxygen index (LOI) increased from 20.5% to 24.5%, and vertical burning tests confirmed a UL-94 V-2 rating with significantly reduced melt dripping. Mechanical testing showed that fibers maintained appropriate tenacity (2.98 g/den), although accompanied by reduced elongation at break, highlighting the trade-off between strength and ductility. SEM/EDX analysis confirmed uniform dispersion of FR particles and the presence of phosphorus and zinc. This approach provides a scalable solution for producing flame-retardant PET fibers without compromising industrial processability, while balancing mechanical performance and fire safety.