Journal of Applied Polymer Science最新文献

Infectious diseases and cancer are two significant groups of diseases attributed to the major death around the globe. There is a need to develop innovative strategies to treat antibiotic resistance bacteria and cancer effectively. In this context, the present work focused on development of calcium oxide (CaO) and CaO modified with chitosan and dopamine nanocomposites (CaO–Cs–Dop) as potential antibacterial, anticancer, and antioxidant agents. The prepared nanoparticles were characterized using various characterization techniques. FTIR revealed the functional groups of prepared samples indicating the successful preparation of nanoparticles. XRD revealed the fcc cubic nature of CaO nanoparticles and the crystallite size was found to be 23 nm for CaO–Cs–DOP and 31 nm for CaO nanoparticles. DLS results confirmed the mean particle hydrodynamic size was found as nm for 231.90 CaO and 189.90 nm for CaO–Cs–DOP nanocomposite. The disk diffusion assay was carried out against common pathogenic bacterial strains as Pseudomonas aeruginosa , Klebsiella pneumoniae , Vibrio cholerae , Escherichia coli , and Shigella dysenteriae . MTT assay was carried out to determine the anticancer activity against MOLT-4 cell line, a human acute lymphoblastic leukemia model. The results indicated that CaO–Cs–DOP nanocomposites exhibited enhanced antibacterial and anticancer activities compared with bare CaO nanoparticles, making them a promising multifunctional agent in biomedical applications.

Adsorbent-based atmospheric water collection technology has great potential in the field of alleviating the shortage of freshwater resources. Here, we prepared the MOF-based hygroscopic polymer material (MPAA) with atmospheric water harvesting and liquid water storage by using MOF-801 with a double copolymerization bond and a three-dimensional structure as a functional monomer and copolymerized with acrylic acid (AA). The atmospheric water-holding properties of the materials at different humidity gradients (50%–90% RH) and their desorption properties under simulated daylight conditions were evaluated. The adsorption of water vapor by MPAA was 628.8 mg/g at the test time of 8 h, which was significantly higher than that of PAA. The field experiment indicated the material's potential to reduce evaporation of soil water, which could potentially be used to store liquid water. This strategy provides new insights into the design of functional materials for atmospheric water harvesting in arid areas and ecological restoration.

High thermal conductivity and high flame-retardant charring properties can meet the technical requirements for fire safety of polycarbonate (PC) used in 5G high-frequency devices. In this study, a novel aluminum maleimide phosphinate (NBAP) with ideal fire-retardant charring properties was synthesized, and a synergistic system of flame retardant and thermal conductivity comprising boron nitride (BN) and NBAP was developed. 3%NBAP/20%BN/PC can obtain outstanding flame retardancy with 37.6% of LOI values and a UL 94 V-0 rating of the vertical burning test; this sample also can obtain 231 kW/m² of PHRR, 33.9 MJ/m² of THR, and 11.2 m² of TSP. The results were much lower than neat PC. This result was attributed to the excellent synergistic charring effect of NBAP and BN, which obtained outstanding flame barrier in the condensed phase. In terms of thermal conductivity, NBAP containing metallic aluminum ions promotes the enhancement of PC thermal conductivity and combined with lamellar BN to build an excellent thermal conductivity pathway, thus effectively increasing the thermal conductivity by 4.57 times compared to neat PC. In a word, this study can provide a significant exploration for constructing high-performance PC composites with fire retardance and heat conduction.

The curing kinetics of a biobased epoxy, formulated based on epoxidized soybean oil (ESO) and isosorbide (ISO), catalyzed by aluminum triflate, Al(OTf)₃, were investigated using differential scanning calorimetry (DSC). The resins were synthesized with catalyst concentrations at 0.05, 0.07, and 0.10 mol% upon two different ratios of ESO to ISO (1:1 and 1:2). The exothermic peak associated with the epoxy ring opening was observed at temperatures ranging from 80°C to 115°C, influenced by both the heating rate and the amount of catalyst. To analyze the curing kinetics and determine the activation energy (E_a) as well as the autocatalytic parameters, both model-free isoconversional and model-based methods were employed. The kinetic mechanism was found to be significantly affected by the catalyst and ISO contents. For compounds with lower concentrations of aluminum triflate, Al(OTf)₃, and ISO, the model-based methods (Bna and Cn) yielded fits with deviations of less than 3%, confirming the autocatalytic nature of the reactions. In contrast, higher concentrations of aluminum triflate, Al(OTf)₃, and ISO led to complex reaction mechanisms, resulting in deviations of approximately 30% and rendering the model-free Friedman and numerical optimization methods ineffective.

Thermoplastic carbon fiber reinforced polyetheretherketone (CF/PEEK) composite materials have broad application prospects in the aerospace field due to their unique recyclability and reusability. This paper proposes a novel heat treatment method aimed at enhancing the tensile properties of drilled CF/PEEK composite laminates based on crystallinity control. The crystallinity of the thermoplastic CF/PEEK composite plays a pivotal role in determining its mechanical properties. The nonisothermal crystallization kinetics of the CF/PEEK composite indicate that the composites have the longest crystallization time and the highest crystallinity at a cooling rate of 2°C/min, which provides a basis for the selection of furnace cooling for heat treatment. The combined heat treatment conducted at 320°C can increase the tensile load of the laminate by up to 25.68%. Digital image correlation technology is used to track the deformation and strain distribution in drilled CF/PEEK samples during the tensile process. Investigation of the tensile failure modes of the drilled laminate indicates fiber fracture and intralaminar failure as the primary mechanisms, with heat treatment effectively strengthening the polymer matrix and, consequently, enhancing the overall tensile performance of the laminates. This research provides valuable insights and practical guidance for optimizing the drilled thermoplastic composites in various industrial applications.

To explore the preparation process and rheological behaviors of polyurethane prepolymer (PUP) modified asphalt binder, based on response surface methodology (RSM), the interactive influence of preparation process parameters on the conventional properties of PUP-modified asphalt binder was analyzed, and its optimal preparation process parameter was first recommended. Then, following the preparation process parameters, the effects of PUP dosage on the conventional indexes, toughness, storage stability, and viscosity of asphalt binder were investigated, and the optimal PUP dosage was determined. Finally, the rheological behaviors of PUP-modified asphalt binder were illustrated via dynamic shear rheological (DSR) test. Results displayed that the preparation process parameters overall had a remarkable and interactive influence on the penetration, softening point, and ductility of PUP-modified asphalt binder, and its optimal preparation method was suggested as follows: unit-preparation weight, shear rate, shear temperature, and shear time were approximately 420–430 g, 3450–3500 r/min, 145°C–150°C, and 30–35 min, respectively. The addition of PUP enhanced the high-temperature performance and low-temperature toughness of asphalt binder while weakening its storage stability. However, the incorporation of PUP with appropriate proportions can ensure the storage stability of asphalt binder satisfied the specification requirement. Synthetically considering the conventional indexes, toughness, storage stability, and viscosity of PUP-modified asphalt binder, the optimal PUP dosage was suggested to be 6% – 10%. The high-temperature deformation resistance of PUP-modified asphalt binder increased with the growing loading frequency, and the modified asphalt binder with 8% PUP content exhibited superior resistance to deformation at a high-temperature situation. When the loading stress exceeded 1000 Pa, the viscoelastic structure of PUP-modified asphalt binder changed, and when the stress reached approximately 1530.8 Pa, the PUP-modified asphalt binder began to yield.

Microcapsule-based self-healing systems, capable of remediating epoxy resin fatigue microcracks, present promising prospects for prolonging their service life. However, there is a pressing need to improve the mechanical properties, especially toughness, of the composite resin. Herein, a dual-compartment microcapsule was proposed to ingeniously integrate into the epoxy resin matrix, which could endow the composites with improved toughness and the remarkable capability of self-repair against intrinsic injuries. Preparation methods included the soap-free emulsion polymerization for PSA nanoparticles loaded with the healing agent, alongside the development of PDA nanoparticles encapsulating a catalyst through Pickering emulsion polymerization. Subsequently, a composite microcapsule was assembled via a coupling reaction between PSA and PDA nanoparticles. Self-healing performance indicated that the incorporation of 2 wt% microcapsules could significantly restore the tensile strength of epoxy resin to 68.37%. Remarkably, the long-term anti-corrosion of the epoxy coating with microcapsules was typically improved using electrochemical impedance spectroscopy measurements. The low-frequency impedance logarithm value of the composite coating remained stable at approximately 7.1, whereas the pure epoxy coating has dropped to 4.8. Furthermore, epoxy/microcapsule composite resin exhibited UV aging resistance and commendable storage stability at ambient conditions. This strategy provides epoxy resin with improved toughness, corrosion resistance, anti-UV irradiation, and self-healing performance.

To achieve the intermediate step, an aromatic polyimide (API) soluble in polar solvents was synthesized via a polycondensation reaction. The synthesized API was characterized using some characterizations. Theoretical investigations were conducted on API polymer units utilizing density functional theory (DFT). The influence of the topological structure on the photodiode's performance was examined. The API material was deposited onto p-Si through the thermal evaporation method. The electrical parameters of the fabricated structure, including the ideality factor (n) (ranging from 2.5 to 4.5), barrier height (Φ_B) (0.70–0.35 eV), and series resistance (R _s) (4.41–169.38 kΩ), were determined via I–V measurements at varying temperatures using the TE method, as well as Cheung and Norde functions. Furthermore, the photocurrent characteristics under different light intensities at room temperature and in dark conditions were analyzed. The evaluation of photodiode and photodetector-related measurements, along with photovoltaic parameters, indicates that this material has the potential to serve as an alternative for optoelectronic applications.