Journal of Applied Polymer Science最新文献

Surface interactions critically govern the adhesion and stability of composite materials used in electronic and structural devices. However, quantitative evaluation of microscopic interfacial forces remains challenging due to the limitations of conventional techniques such as quartz crystal microbalance and atomic force microscopy. To address this issue, a particle dissociation technique based on a coupled acoustic–gravitational (CAG) field was employed to quantify the interactions between silicon nitride particles (SNPs) and polyimide (PI) films with different fluorine contents. In this method, the applied acoustic radiation force required for particle dissociation was translated into the dissociation voltage (V), providing a quantitative measure of interfacial binding strength on the order of several hundred piconewtons. This study is positioned within the field of materials and surface science, aiming to establish an acoustically driven analytical approach for quantifying adhesion strength at solid–solid interfaces. Unmodified PI film showed a higher V (33.5 V) than glass (19.1 V), indicating hydrogen-bonding interactions, whereas fluorinated PI films exhibited lower V values (23.5–26.1 V) due to weaker fluorine–silicon affinity. A PI film with moderate fluorine content displayed two distinct dissociation profiles, reflecting the coexistence of hydrogen-bonding and fluorine–silicon interactions. The CAG-based particle dissociation method thus provides a versatile tool for quantitative analysis of interfacial adhesion in functional thin films.

This work aims to prepare a long-lasting, high-flux and hydrophilic PTFE hollow fiber membrane for treating highly polluted wastewater, using a dopamine (DA)-based co-deposition strategy. To study the effects of different generations of poly(amido-amine) (PAMAM), the mass ratio of DA/PAMAM, and the co-deposition time on the hydrophilicity properties of the membranes, hydrophilic coatings were prepared on the surface of PTFE hollow fiber membranes by co-deposition using DA and two generations of hyperbranched poly(amido-amine) (PAMAM) as substrates. The pure water flux and water contact angle of the modified membrane varied with mass ratio (DA/PAMAM) and time. Through the use of edible oil and bovine serum albumin (BSA) as simulated pollutants, the dynamic cross-flow contamination experiments demonstrated the enhanced resistance of the modified membranes to both protein and oil contamination. After strong acid (pH = 1), alkaline (pH = 13) and repeated rinsing, the modified membrane still maintained its hydrophilicity and stability. Overall, the modification process is simple, environmentally friendly and effective. Notably, the optimized MPDA/PAMAM membrane at a DA/PAMAM mass ratio of 1:1 presented the highest pure water flux of 2354.6 L·m⁻²·h⁻¹, the lowest contact angle of 32.3°, and stable performance across pH 1–13, showing promising application potential in wastewater treatment with high pollution levels.

We synthesized four types of high-performance thiophene-based aromatic polyamides under mild conditions. These include POT (a polyamide derived from triazine and ethylenepiperazine), PAT (a phthalimide-triazine oligomer-based polyamide), PIOT (another phthalimide-triazine oligomer variant), and POAT (an advanced triazine-polyamide). The polymerization was carried out using 2,5-thiophenedicarbonyl dichloride (TDCl) and diamine as monomers. The chemical structure of the polyamide was characterized by H-NMR and Fourier transform infrared spectroscopy (FTIR). Thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA) tests showed that the polyamide has outstanding thermal stability and mechanical properties. The temperature range corresponding to 5% thermal weight loss of the four polyamide resins was 353.5°C–411.0°C. This thermal property is comparable to that of the benzene-ring-containing semi-aromatic polyamide studied by Gang Zhang et al. (380°C–400°C). The Young's modulus of the POT and PIOT films of polyamide was 1441.65–2447.06 MPa, the tensile strength is 74.77–79.96 MPa, and the elongation at break is 5.69%–8.26%. These results pave the way for thiophene-aromatic polyamides to be used as high-performance special engineering plastics. It also provides a reference for the substitution of thiophene for the benzene ring.

The poor compatibility between biodegradable polylactic acid (PLA) and poly (propylene carbonate) (PPC) limits the blends' performance and hinders agricultural applications. In this study, hydrophobically modified cellulose nanocrystals (CNC-DDA) were prepared and incorporated into the PLA/PPC blend as nano-compatibilizers to improve the multi-scale structure of the blend for enhancing properties. CNC-DDA was uniformly dispersed at the PLA/PPC interface and in PLA, reducing PPC dispersed phase size and forming interfacial hydrogen bonds to enhance interfacial interactions. Furthermore, the CNC-DDA acted as effective heterogeneous nucleating agents, highly improving PLA's crystallization properties, including crystallinity, crystallization rate, and crystal size. Enhancements in morphology, interface, and crystallization multi-scale structure synergistically contributed to a significant increase in the tensile strength and elongation at break of the PLA/PPC blend, with improvements of approximately 93.9% and 43.1%, respectively. Furthermore, the incorporation of CNC-DDA improved the barrier property and biodegradability of the blend while maintaining favorable light transmittance. The excellent integrative properties of the PLA/PPC/CNC-DDA composite promoted cherry radish growth. This study presents a valuable and effective approach for enhancing polymer blend compatibility, offering new prospects for designing high-performance biodegradable agricultural mulching films.

Currently, traditional flame-retardant-modified rigid polyurethane foam (RPUF) suffers from poor mechanical properties, flame-retardant migration, and insufficient environmental resistance due to issues in water resistance and compatibility during use. This work employs microencapsulation technology to modify pyrophosphate piperazine (PAPP), successfully preparing polyurethane-coated flame retardant (PUPAPP), which is then incorporated into the RPUF matrix by a one-step fully aqueous foaming technique to produce high-performance RPUF composites. The encapsulation of the PU shell significantly improves the dispersion and compatibility of PAPP in the matrix, resulting in superior mechanical properties of the RPUF/PUPAPP composite compared with the RPUF/PAPP system. Additionally, the migration of PAPP is effectively suppressed, reducing the oxygen index decline rate by 37% after immersion. Furthermore, adding 50 parts of PUPAPP increases the limited oxygen index (LOI) value of the RPUF/PUPAPP composite to 22.9 vol%, achieving UL-94 V-0 grade. In addition, the utilization of PUPAPP increases the initial decomposition temperature of the RPUF composite by 32°C, promotes the formation of a dense char layer, and reduces the peak heat release rate by 28.6%. This work provides insights for the development of functionalized flame retardants and high-performance RPUF composites.

Epoxy resin (EP) is widely used in construction, aerospace, and electronics to enhance product safety and prevent fire hazards. However, it is hard to balance flame retardancy, heat resistance, and the mechanical properties of the EP matrix during production. In this paper, a novel halogen-free phosphorus-based EP composite featured with high flame retardant and heat resistance, was successfully synthesized by introducing a co-curing agent, namely a halogen-free phosphorus-based flame retardant, designated as DNEA into the EP matrix. It is found that the coke output of the resulting EP composite at 600°C can even be raised by 100% with an 8 wt% dosage of DNEA. Moreover, the sample possesses the limiting oxygen index (LOI) of 29.5% and meets the UL-94 V-0 flammability rating. In addition, the heat release rate (HRR) and total heat release (THR) of the phosphorus-based EP composite were reduced greatly by 30.3% and 19.1%, respectively. Owing to the good compatibility between DNEA and EP, the phosphorus-based EP composite exhibited a high tensile strength of 87.5 MPa and a high tensile modulus of 2916 MPa. Therefore, the phosphorus-based EP composite in this paper is expected to be applied in high-temperature resistant insulating coatings, electronic packaging materials, and related fields.

Water scarcity is a critical global issue requiring sustainable and efficient desalination. This study introduces a novel eco-friendly hollow fiber nanofiltration membrane for water desalination, employing a wet spinning method to create membranes from polyether sulfone (PES), polyethylene glycol (PEG), and polyvinylpyrrolidone (PVP). The prepared membrane demonstrated significant improvements in pure water permeability (PWP) and salt rejection rates, achieving up to 94% rejection. Scanning Electron Microscopy (SEM) analysis revealed a unique asymmetric structure characterized by small macro-voids towards the outer edge of the membrane. Increasing the dope extrusion rate (DER) from 2.0 to 2.5 cm³/min notably enhanced molecular orientation, optimizing rejection rates. Additionally, increasing the pH elevation from 5.5 to 6.5 further improved rejection due to altered membrane surface charges. Long-term and thermal stability assessments confirmed robust membrane performance over a temperature range of 10°C–70°C, indicating its viability for diverse applications. This research significantly contributes to overcoming existing knowledge gaps, particularly regarding the effects of the dope extrusion rate (DER), and advances practical, sustainable desalination technology.

This study achieves precise morphological control of beaded fibers by electrospinning immiscible polycarbosilane (PCS) and polyvinylpyrrolidone (PVP) hybrid solutions. Through systematic orthogonal experiments, we investigated the key operating conditions: PCS/PVP ratio, applied voltage, injection rate, and receiving distance. ANOVA analysis quantified their distinct impacts, revealing that the PCS/PVP ratio is the dominant factor governing fiber length (44.4% effect rate) and bead width (39.1%), while applied voltage primarily controls bead length (33.7%). Furthermore, the combination of a lower injection rate (e.g., 0.9 mL/h) and a higher voltage (e.g., 16 kV) was identified as an effective strategy for achieving refined, uniform nanoscale beaded fibers. This research provides a quantitative framework for tailoring beaded fiber morphology, suggesting their potential for future applications in fields such as optics, biomedicine, and advanced textiles.

Poly(butylene adipate-co-terephthalate) (PBAT) is a biodegradable polymer widely used in various industries, including agriculture and medicine, due to its favorable physical and environmental properties. However, to reduce oxygen permeability, fillers, such as expanded graphite (EG) are used. EG is obtained by expanding graphite and is considered a suitable reinforcing agent for polymers because of its high specific surface area, good thermal and electrical conductivity, and low weight. In this study, PBAT/EG composites with different weight percentages were synthesized using the in situ polymerization method, in which PBAT monomers are polymerized in the presence of EG. This method improved EG dispersion and composite properties. Tensile testing revealed that the composite with 1 wt.% EG exhibited a unique mechanical response, characterized by an increase in elongation at break from 602% to 620% compared to neat PBAT, enhancing its ductility. This was accompanied by a reduction in tensile strength, a trade-off that distinguishes the behavior of these in situ polymerized composites from conventionally melt-mixed systems. The primary enhancement, however, was observed in the barrier properties. Hydrolytic biodegradation tests showed that increasing the EG content enhanced degradation by up to ~15 wt.%, while the soil degradation rate decreased. Additionally, the composites exhibited reduced oxygen and water vapor permeability.

In this paper, a range of inorganic particles (Al₂O₃, SiO₂, TiO₂, and ZrO₂) is combined with PC to prepare composites, respectively. The effect of surface properties of inorganic particles on the flame retardancy of PC was studied. The particles were characterized by transmission electron microscopy, zeta potential and contact angle analysis, combined with molecular dynamics simulation. Flame retardancy was evaluated by vertical combustion, limiting oxygen index and cone calorimetry. The results show that the addition of Al₂O₃ has the best overall performance in terms of dispersibility and compatibility with PC, and the adsorption energy of the Al₂O₃/PC interface is the highest. The incorporation of Al₂O₃, SiO₂, TiO₂ and ZrO₂ improves the flame retardancy of PC. Compared with pure PC, the incorporation of Al₂O₃ significantly improves the thermal stability and residual mass of PC, resulting in a 21% increase in LOI and a 35% reduction in peak heat release rate. It is found that the compatibility of Al₂O₃ particles with PC is the best, which can significantly improve its thermal stability and flame retardant performance, showing the best comprehensive performance. This method can be widely used in electronic, electrical and automotive fields, and can effectively improve the safety and reliability of materials.