Journal of Applied Polymer Science最新文献

Adhesives are essential in diverse industrial fields, and bioadhesives play a critical role in medicine for minimally invasive tissue repair and device integration. However, existing systems, particularly polyethylene glycol (PEG)-based adhesives, often suffer from brittleness, inadequate performance under extreme temperatures, and limited substrate versatility. To overcome these challenges, we developed a novel polyphenol-PEG adhesive platform through citric acid (CA)-mediated liquid–liquid phase separation (LLPS). This process, driven by CA-regulated hydrogen bonding as confirmed by XPS, FTIR, UV spectroscopy, and solution studies, produces adhesives with exceptional properties: peel strength near 15 N/cm, shear strength exceeding 4 MPa on hydrophilic substrates, rapid adhesion within 10 s, and operational stability from liquid nitrogen temperatures up to about 150°C, maintaining over 1 MPa shear strength at 200°C exposure. The adhesive demonstrates effective sealing of fractured bone, adhering to wet biological tissues and serving as an eco-friendly solution for restoring cultural artifacts. This study establishes the condensate formed by the CA-regulated LLPS process in the polyphenol-PEG system as a novel, ultra-robust adhesive suitable for demanding biomedical and industrial applications.

Poly(methyl methacrylate) (PMMA) exhibits a high coefficient of friction, limiting its use in tribological applications. To address this, graphene oxide (GO), synthesized via the Hummers method, is functionalized with silane KH570 to enhance its compatibility and subsequently incorporated into PMMA through in situ bulk polymerization, resulting in PMMA/KH570-GO composites. The structural, morphological, and functional properties of the composites are characterized using x-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), and atomic force microscopy (AFM). Mechanical and tribological behaviors are assessed through tensile and pin-on-disc tests. The results indicate that the addition of 0.06 wt% KH570-GO enhances tensile strength by 13.4%, achieving a value of 76.25 MPa, and significantly reduces the coefficient of friction from 0.7 to 0.25, compared to pure PMMA. Beyond this threshold, a higher KH570-GO loading of 0.20 wt% diminished the tensile strength to 59.23 MPa. The optimal content, in contrast, improved mechanical properties and promoted the development of a lubricating graphitic film during friction, which collectively contributed to a marked enhancement in tribological performance.

This study aims to address the challenge of treating Pb²⁺ in mining wastewater, a persistent issue in water environment pollution control. The sodium alginate/graphene oxide/polyethylene glycol (SA/GO/PEG) gel beads were designed and prepared with graphene oxide (GO), sodium alginate (SA), and polyethylene glycol (PEG) as raw materials by combining experiments and simulation. Firstly, the simulation system of SA/GO/PEG gel bead was constructed through molecular simulation, and the optimal composition of SA/GO/PEG gel bead was determined. The simulation results indicated that, with a PEG polymerization degree of 4000, the SA/GO/PEG gel bead system exhibited the greatest structural stability and the most effective cross-linked. Based on the understanding of the structure–performance relationship, SA/GO/PEG4000 gel beads were prepared to achieve an adsorbent with both high adsorption capacity and good stability. Characterization results indicated the successful cross-linked of polyethylene glycol with sodium alginate and graphene oxide, which not only introduced additional oxygen-containing functional groups and increased the crystallinity of the gel beads but, more importantly, led to the formation of a dense and complex three-dimensional network. This structure contributed to the improved thermal stability of the composite. Adsorption experiments showed that the adsorption of Pb²⁺ onto SA/GO/PEG gel beads followed the Langmuir isotherm model. The calculated maximum adsorption capacities at 25°C, 35°C, and 45°C were 490.20, 497.51, and 526.32 mg/g, respectively. Furthermore, the gel beads exhibited excellent reusability, retaining 92.64% of their initial adsorption capacity after four consecutive adsorption–desorption cycles.

With the escalating severity of air pollution and its associated threats to human health, there is an urgent need to develop high-efficiency air filtration materials to mitigate the risk of particulate matter inhalation. This study employed electrospinning technology to fabricate SiO₂ aerogel composite nanofiber membranes with enhanced filtration performance by incorporating SiO₂ aerogel into the spinning solution. The influence of SiO₂ aerogel content on the microstructure, thermal stability, filtration performance, and water resistance of the nanofiber membranes was systematically investigated. The results indicated that the composite membranes exhibited uniform fiber diameter distribution and maintained filtration efficiencies exceeding 99%. The membrane with 0.5 wt% SiO₂ aerogel content demonstrated an optimal balance between filtration efficiency (99.54%) and pressure drop (66.72 Pa). Furthermore, the prepared membranes exhibited excellent air permeability (62.55 mm/s) and suitable hydrostatic pressure resistance (613 Pa), which are beneficial for practical applications. This study successfully developed nanofiber membranes integrating high filtration efficiency, breathability, and hydrophilicity, contributing to reduced inhalation risks of harmful particles and holding significant potential for advancing the development and application of high-performance air filtration materials.

To improve the interfacial adhesion between the phthalonitrile resin and the reinforcing fibers, and also to investigate the influence of the addition of epoxy resin on the crosslinking structures and properties, a small amount of high-performance epoxy resin with four epoxy groups (AG80) in its chemical structure was introduced into a phthalonitrile resin (BAPh) to prepare composites with the basalt fiber cloths. It was found that proper amount of AG80 could increase the curing reactivity of BAPh with lowered curing temperature and shortened gelation time. And AG80 could also improve the interfacial interaction between the resin matrix and the fibers, thus enhancing the flexural strength. With 0.5 wt% of AG80, the flexural strength of BF/0.5EBAPh reached 513.2 MPa, 205.4 MPa higher than that of the BF/BAPh. Moreover, due to the better interfacial interaction and higher curing degree, the thermal properties and dimensional stability also improved when proper amount of epoxy introduced. Specifically, BF/0.5EBAPh showed T _{g tanδ} of 382°C and CTE of 18.2 ppm/K, which were 11°C higher and 12 ppm/K lower than those of the BF/BAPh.

We explored the tailorability of resin processing behavior, thermal stability, and thermomechanical properties through the formulation of two well-established phthalonitrile (PN) monomers: the bisphenol A derived PEEK-based PN resin (BisA-PEEK-PN) and a low-viscosity and highly processable phosphate-based PN monomer (PPN) with exceptional thermooxidative stability. The resins were melt blended in varying ratios and the results of this research offer a simple method for lowering the processing temperature by 25 to 50°C and melt viscosity from 1 to 0.75 Pa s at 175°C of the blended resin. As more PPN is mixed into the BisA-PEEK-PN blend, a 3.7 GPa (238%) increase in the room temperature storage modulus was observed and it was also found to dramatically improve the thermooxidative stability of cured network blends, as indicated by an increase in the char yield (1000°C, air) from 5% to 55%. In addition, a synergistic effect between the oxidatively stable PPN and BisA-PEEK-PN in the blend was observed in blended networks which exhibited a maximum char yield of 79% under N₂, surpassing either of the neat resins.

We report an optimized epoxidation route for black seed oil (BSO) using in situ performic acid generated from H₂O₂ and formic acid under moderate temperature, metal-free and chlorinated-solvent-free conditions. After a range-finding one-factor-at-a-time study (60°C–80°C; H₂O₂/C=C = 1.00–2.00; 60–120 min), a three-factor Box–Behnken design (65°C–75°C; 1.00–1.50; 110–130 min) was employed to maximize epoxide formation while limiting side reactions. FTIR, 1H NMR, and 13C NMR corroborated the selective conversion of C=C to oxirane. The operating optimum—70°C, H₂O₂/C=C = 1.25, 120 min—afforded 98.22% conversion and an epoxide content of 5.96 mol mol⁻¹ oil; confirmation runs yielded 96.63% (1.62% deviation), supporting model predictability. The quadratic model exhibited excellent statistics (R ² = 0.9998; Pred-R ² = 0.9971) with global desirability = 1.000 under a single-objective target (maximize conversion). Coating-scale feasibility was demonstrated in epoxy–amine films containing EBSO, which show the expected plasticization trade-off—improved compliance/flexibility and higher gloss at the expense of strength/modulus—alongside a decrease in the apparent low-temperature onset (T _5% and T _10%) associated with early mass loss, a modest shift of the main DTG peak temperature (DTG-T _max), and reduced char yield, while maintaining adequate thermal stability for coating applications. These results position epoxidized BSO as a renewable, reactive building block for thermosetting polymers and UV-curable coatings. Overall, the study provides a statistically validated, scalable processing window for epoxidation of BSO and, to the best of our knowledge, is among the first to directly couple an RSM-optimized peracid epoxidation of black seed oil with a systematic evaluation of epoxy–amine coating performance on cementitious substrates, thereby illustrating how an underutilized regional oil can be upgraded into high-performance epoxy-based coatings.

New di-imidazole cored bisphenol (DIBP)-based benzoxazines (DIBP-BZ) were synthesized using three different amines, like furfuryl amine (fa), lauryl amine (la), and stearyl amine (sa), separately with paraformaldehyde through the Mannich condensation reaction. Incorporation of the imidazole core into the polymer backbone imparts self-catalytic activity, significantly lowering the curing temperatures (205°C–224°C) compared to that of conventional benzoxazines (typically above 250°C). The prepared DIBP-BZ monomers are capable of curing at lower temperatures by blending with fossil-based bisphenol-F-epoxy (BFE) resin and bio-based cardanol-bisphenol epoxy (CBE) resin in a weight ratio of 1:1 to obtain hybrid polybenzoxazine-epoxy networks. These hybrid systems exhibit enhanced thermal stability, lower dielectric constant and dielectric loss, minimal moisture absorption, and superior hydrophobicity relative to conventional benzoxazine–epoxy blends. The poly(DIBP-sa)/CBE hybrid shows an exceptional corrosion protection, attaining an inhibition efficiency of 99% after 15 days, followed by a marginal reduction thereafter, according to electrochemical corrosion studies conducted in 3.5 wt% solution of NaCl, for a period of 30 days (evaluated at 15-day intervals). Further, the poly (DIBP-sa)/CBE system exhibits excellent dielectric performance, with a dielectric constant of 2.93 and a dielectric loss of 0.052, highlighting its potential as a high-performance material for advanced coating and low-k microelectronics applications.

In this work, two PBS poly(butylene succinate) films composed on one hand of neat PBS and on the other hand of PBS containing 1 wt% of silica are uniaxially stretched at 85°C up to a draw ratio (DR) of 6. The influence of stretching on the chain mobility and on the crystallinity is investigated by differential scanning calorimetry (DSC). WAXD analysis shows that the stretching process induces a preferential orientation in the crystalline phase with the alignment of the c-axis of the crystal lattice in the drawing direction. As evidenced by SAXS analysis, upon stretching, a complex microstructure is created involving a two-scale texturing: at a small scale in the stretching direction and at a larger scale in the transverse direction. Based on DSC and SAXS results, the development of this microstructure is assigned to a fibrillation phenomenon. Gas permeability does not vary monotonically as a function of DR: it increases for DR values up to 3 and then decreases. This unusual behavior is discussed as a function of the respective evolution of the polymer structure, crystallinity and chain mobility, the effect of the silica filler being mostly observed for DR up to 3.

Natural silk textiles with passive radiative cooling properties show promising potentials for energy-efficient personal thermal regulation. Herein, the thermal regulation patches (SF@Gly-BN) based on silk fibroin (SF), glycerin (Gly), and boron nitride nanoflakes (BNFs) are fabricated. The incorporation of BNFs enhances the solar reflectance from ~0.3 to ~0.7 in the high solar spectrum region while maintaining a high infrared emissivity of ~0.85 in the mid-infrared region for SF@Gly-BN patches. The enhancement of these optical properties endows the SF@Gly-BN patches with excellent passive radiative cooling performance. Indoor tests show a ~14.7°C sub-ambient temperature drop for the SF@Gly-BN patch with 20 wt% BNFs, whereas the outdoor testing exhibits an average sub-ambient temperature drop of ~14°C on the clear days with the average solar irradiance of 1050 W m⁻². Moreover, the SF@Gly-BN patch shows great potentials for personal thermal regulation which can reduce skin temperatures by ~6.5°C and ~3.0°C respectively in outdoor and indoor conditions. This research offers an approach to developing efficient, eco-friendly, and biocompatible wearable thermal management products.