Journal of Applied Polymer Science最新文献

Acrylonitrile-butadiene-styrene (ABS) resin faces significant fire hazards due to inherent flammability, necessitating halogen-free flame retardants with minimal mechanical compromise. Herein, novel cerium diethylenetriamine penta(methylene phosphonate) (CeDETPMP) complexes were molecularly engineered via hydrothermal synthesis, systematically tuning Ce³⁺-to-ligand ratios (from 1:3 to 3:1) to optimize coordination geometry. At 1 wt% loading, CeDETPMP synergized with an intumescent flame retardant (IFR, 19 wt% ADP/PAPP) to enable ABS composites to achieve UL-94 V-0 rating and a limiting oxygen index (LOI) of 24.8%, while reducing peak heat release rate (PHRR) by 73.8% and total smoke release (TSR) by 35.4% in cone calorimetry. Crucially, Ce³⁺/Ce⁴⁺ redox cycling catalyzed graphitized char formation, suppressing crack propagation and enhancing barrier integrity. The optimal CeDETPMP (1:3) and CeDETPMP (3:1) ratios minimized mechanical sacrifice compared to ABS/IFR systems, retaining tensile strength within 26 MPa and 11 kJ/m². This work establishes a structure–property paradigm for rare-earth synergists in high-safety polymer engineering.

Manganese ferrite (MnFe₂O₄, MnF) nanoparticles were synthesized via a co-precipitation route and subsequently surface-functionalized with polyethylene glycol (PEG) through a mass titration method. Structural and morphological analyses (SEM, XRD, EDX, FTIR) confirmed a monophasic cubic spinel structure with an average crystallite size of 23 nm and a slight grain growth after PEG modification. DM simulation revealed the homogeneous grafting of PEG without interfering with the parent spinel structure of MnF. Magnetic measurements (VSM, ZFC) revealed superparamagnetic behavior for pristine MnF (M_s = 37.25 emu g⁻¹) and a transition to weak ferromagnetism for PEG@MnF (M _s = 22.7 emu g⁻¹), attributed to surface modification. Dielectric studies further highlighted the multifunctional nature of the material. Photocatalytic performance was evaluated via the degradation of thiamethoxam, a widely used pesticide. Under optimal conditions (80 min, 10 ppm, 0.04 g catalyst, 65°C), PEG@MnF exhibited significantly enhanced degradation efficiency compared to unmodified MnF, owing to improved dispersibility, reduced agglomeration, and a higher density of active sites imparted by PEG. Degradation intermediates were identified using GC–MS and FTIR, and a plausible degradation pathway was proposed. These results demonstrate that PEG functionalization markedly improves the magnetic, dielectric, and photocatalytic performance of MnF, establishing PEG@MnF as a promising catalyst for sustainable environmental remediation.

With the rapid development of aerospace technology, solid rocket motors have put forward higher requirements for the comprehensive performance of insulation materials. Chloroprene rubber (CR) is widely regarded as an ideal matrix for thermal insulation materials due to its excellent tensile strength, high elongation at break, and good flame-retardant properties. In this study, a flexible and ablation-resistant composite insulation material was prepared by adding nano cerium oxide (CeO₂) to the CR/poly-p-phenylene terephthamide pulp (PPTA-pulp) composite matrix, and the effect of CeO₂ on its mechanical and ablation-resistant properties was systematically studied. Based on this, a three-component thermal conductivity model of CR/PPTA-pulp/CeO₂ was constructed, and molecular dynamics simulations were carried out with Reverse Non-Equilibrium Molecular Dynamics (RNEMD) to predict its thermal conductivity. The results show that when the amount of CeO₂ is added at 0.25 phr, the tensile strength and elongation at break are increased by 25.9% and 17.6%, respectively, while the linear ablation rate and thermal conductivity are reduced by 52.0% and 16.9%, respectively. The positive role of CeO₂ in enhancing the ablation performance of materials was confirmed by molecular dynamics simulation.

This work tackles the challenge of flame-retarding high-porosity (porosity > 70%) polyphenylene oxide-polystyrene (PPO/PS) composite foams with traditional condensed-phase flame retardants. A synergistic system of phosphate ester (PX220) and brominated compound (BPS) was developed, relying on gas-phase flame retardancy (primary) and condensed-phase barrier/smoke suppression (supplementary). Their complementary decomposition temperatures enable timely gas-phase product release to suppress PPO/PS thermo-oxidative degradation, while PX220's plasticization improves BPS dispersion. For unfoamed samples, the system achieved a maximum LOI of 36.4%, with HRR reduced by up to 17 MJ/m² (4.8% higher than single systems). It also lowers smoke release via intumescent char. For 85% porosity foams, LOI reached 25.4% (HF-1 pass), and even at > 90% porosity, HRR and melt dripping were suppressed. Moreover, PX220 and BPS refine cell morphology (via viscosity reduction and heterogeneous nucleation), increasing compressive strength by 0.67 MPa at 85% porosity. This study provides a novel flame-retardant approach and strategy for lightweight, high-performance PPO/PS composite foams.

Epoxy-modified polysulfide is widely used in coatings and as an adhesive for rocket insulation. Understanding the curing process is essential for enhancing the properties of the material. This research investigates the curing kinetics of epoxy-modified polysulfide and examines how curing temperature influences its characteristics. In the study, epoxy, polysulfide, and cycloaliphatic amine curing agents are mixed and cured at 25°C, 40°C, and 60°C. The curing durations are determined based on a kinetics model. The curing kinetics are analyzed using differential scanning calorimetry (DSC), employing the Prout-Tompkins autocatalytic method for modeling. Changes in molecular structure during the curing process are assessed using second derivative analysis from Fourier Transform Infrared Spectroscopy (FTIR). Additionally, the mechanical properties such as hardness, tensile strength, elongation, elastic modulus, and density are measured using a Shore D durometer, a universal testing machine, and a densitometer. Phase separation is examined with a scanning electron microscope (SEM). The results indicate that higher curing temperatures increase density, hardness, tensile strength, and elastic modulus by factors of 1.013, 2.38, 1.75, and 14.95, respectively, while reducing flexibility by 0.75 times. Although phase separation does not occur, higher temperatures do affect the product's opacity.

Poly(ethylene oxide) (PEO) is a promising candidate to fabricate solid polymer electrolytes (SPEs). To improve the comprehensive performances of PEO-based SPEs, vinylidene fluoride (VDF) copolymers grafted with poly(ethylene glycol) were electrospun and applied as a support for the PEO matrix. The grafting of PEG onto the VDF copolymer was achieved by the nucleophilic substitution of a chlorine atom in the VDF copolymer by methoxy-polyethylene-glycol thiol. The ionic conductivity of the VDF copolymer was increased with the grafting site density of PEG at the same bis(trifluoromethane sulfonimide) (LiTFSi) concentration. SPEs were fabricated by solution casting of PEO/LiTFSi onto electrospun VDF graft copolymer fibers. Electric field poling induces a beneficial α-to-β phase transition in the VDF copolymer, and the compatibility between the VDF copolymer and PEO was improved due to the incorporated PEG side chains, which facilitate lithium ion (Li⁺) transport through additional conduction pathways and enhance lithium-ion solvation. The supported PEO SPEs exhibited good mechanical strength and toughness, and the optimized SPE with an EO/Li ratio of 6:1 exhibits excellent electrochemical performance at 60°C, including an ionic conductivity of 1.79 × 10⁻⁴ S cm⁻¹, a Li⁺ transference number of 0.49, and a wide ESW of 5.46 V (vs. Li⁺/Li).

This study reports the synthesis of an inherently hydrophobic, bio-based polyurethane foam (Bio-HPUF) derived from hemp seed oil (HSO) for efficient oil–water separation. Unlike conventional polyurethane foams, Bio-HPUF was synthesized without solvents, blowing agents, or catalysts, using HSO-derived polyol and hexamethylene diisocyanate (HDI). Structural characterization via FTIR confirmed successful urethane formation, while SEM revealed an open-cell porous morphology with pore sizes ranging from 163–567 $��\mu �$m. Thermal analysis showed multi-stage degradation with stability up to 330°C. The foam exhibited a water contact angle of 91° and an oil contact angle of 16°, indicating hydrophobic and oleophilic behavior. It demonstrated selective sorption capacities up to 1–27.8 g/g for oils and organic solvents, rapid oil uptake within 15 s, and high selectivity in water. Reusability studies showed minimal loss in performance over 10 oil adsorption–desorption cycles. The foam also maintained $��>�$ 99% of its original mass after 24 h exposure to acidic, saline, and basic media, with no structural degradation. Notably, Bio-HPUF effectively separated toluene-in-water emulsion, showed excellent compression recovery with self cleaning abilities, affirming its applicability in complex systems. These results highlight the material's sustainable synthesis, structural robustness, and high selectivity, positioning it as a promising sorbent for environmental oil remediation.

This study investigated the tribological properties of epoxy nanocomposites reinforced with graphene (Gr), graphene oxide (GO), and reduced graphene oxide (rGO) at concentrations of 0.15 and 0.6 wt%. Comprehensive structural characterization was performed using SEM, EDX, XRD, FTIR, and Raman spectroscopy to evaluate nanoparticle morphology, chemical composition, and crystal structure. Pin-on-disk wear tests assessed friction coefficient and weight loss under controlled conditions. SEM analysis revealed planar layered structures in Gr, while GO and rGO exhibited wrinkled morphologies due to oxygenated functional groups. EDX confirmed pure carbon composition (100%) in Gr, with oxygen content of 44.82 wt% in GO and 34.62 wt% in rGO. XRD analysis demonstrated interlayer distances of 0.34 nm, 0.78 nm, and 0.61 nm for Gr, GO, and rGO, respectively. FTIR and Raman spectroscopy confirmed stronger matrix interactions in GO due to functional groups, while Gr maintained superior structural order. Tribological testing revealed that Gr at 0.6 wt% exhibited optimal performance with 41.67% reduction in friction coefficient and 77.78% decrease in weight loss compared to neat epoxy. This superior performance is attributed to the well-ordered sp² layered structure and inherent lubricating properties of graphene. GO performed weakest, while rGO demonstrated intermediate behavior. These findings provide insights for designing epoxy nanocomposites with enhanced tribological properties for industrial applications.

Amid the global “double-carbon” initiative, melting-grafted polypropylene (PP) insulation presents a promising technical route for next-generation power cable systems due to its recyclability, satisfactory dielectric performance, and engineering practicality. However, its universality across both high-voltage alternating current (HVAC) and direct current (HVDC) systems remains to be fully assessed. In this study, we selected a mature polar grafted PP system: glycidyl methacrylate (GMA)-grafted PP, to experimentally evaluate its performance and elucidate the underlying physical mechanisms. The results demonstrate that GMA-grafted PP exhibits excellent DC dielectric performance, including a 24.6% enhancement in breakdown strength and significantly improved space charge distribution, whereas its performance under AC conditions remains unsatisfactory. The GMA-induced trapping-detrapping process is proved a key factor contributing to DC improvements, while the study also highlights that polymeric degradation during the melting grafting process, as well as the high polarity of GMA, are responsible for the unfavorable AC performance. In conclusion, 5% (weight percent) GMA-grafted PP is highly suitable for HVDC cable insulation, but the degradation associated with the melting grafting process is a crucial and urgent issue to be addressed, for the development and universality of high-capacity recyclable cable systems.