Chinese Journal of Polymer Science最新文献

Polybutene-1 (PB-1) is a semi-crystalline polymer with excellent mechanical properties. However, its practical application is significantly hindered by the slow Form II-I transition, which can take up to several days to complete. While prior research established that long-chain branching (LCB) structures synthesized via ω-alkenylmethyldichlorosilane copolymerization-hydrolysis (ACH) chemistry markedly accelerate this transition, this work demonstrates that H-shaped LCB structures constructed through copolymerization with 1,9-decadiene exhibit the capability to facilitate Form II-I transition in most systems evaluated herein. However, low branching efficiency concurrently generates extended alkyl pendant chains, which impose pronounced steric-hindrance-driven suppression on the transition kinetics, thereby substantially diminishing the net acceleration effect of the LCB structures, even resulting in a net retardation effect in certain systems. Notably, a significant synergistic acceleration effect emerged between the H-shaped LCB structures and propylene comonomer units. These findings confirm that the H-shaped LCB structures play a role in promoting the Form II-I transformation process, which is independent of the synthetic pathways, thereby providing more strategies for addressing the long-standing processing problems of PB-1.

Two- and three-component deep eutectic solvents (DES) based on acrylic acid (AA), acrylamide (AAm), and choline chloride (ChCl) were used to disintegrate bacterial cellulose into cellulose nanofibers (CNF). As a result, polymerizable precursors suitable for 3D printing with CNF as a rheology modifier and reinforcer with formation of interpenetrating double polymer network were obtained after UV curing. Composite hydrogels were formed by replacing ChCl with water. It was found that the introduction of amide groups into the acrylate polymer matrix resulted in an increase in compressive strength. The layered architecture of the 3D printed products provides greater mechanical strength compared to molded products. The structure of the composites was investigated using wide-angle X-ray scattering (WAXS), small-angle X-ray scattering (SAXS), atomic force microscopy (AFM) and polarized light microscopy. These studies suggest that the enhanced mechanical properties of the 3D printed hydrogels are associated with swelling and branching of CNF in the DES, as well as alignment of the filler during extrusion. For comparative analysis, composite hydrogels were also prepared using aqueous solutions of AA and AA/AAm with dispersed CNF. However, the 3D printing process was hampered in this case due to cellulose agglomeration. Mechanical testing revealed the formation of premature microcracks in these samples, which were not observed in composites produced using DES. Cytotoxicity of the composite hydrogels was also tested. The results provide valuable insights into the production of strong (up to 3.4 MPa) homogeneous composite hydrogels using 3D printing with nanocellulose filler.

In recent years, flexible ionic conductors have made remarkable progress in the fields of energy storage devices and flexible sensors. However, most of these materials still face challenges such as the difficult trade-off between stretchability and high mechanical strength, as well as insufficient ionic conductivity. Among them, polymerizable deep eutectic solvents (PDES), which possess both hydrogen bond network construction capabilities and ionic conduction properties, have demonstrated great advantages in the synthesis of flexible ionic conductors. Herein, we report an ionic conductive elastomer (ICE) named PCHS-X based on PDES composed of 2-(methacryloyloxy)-N,N,N-trimethylammonium methyl sulfate (MA-MS), choline chloride (ChCl), and 2-hydroxyethyl acrylate (HEA). The introduction of MA-MS enabled the polymer network to form abundant hydrogen bonds, endowing PCHS-X with excellent mechanical strength, high transparency, favorable ionic conductivity, self-adhesiveness, and self-healing efficiency. When used as a strain sensor, the PCHS-X exhibits highly sensitive strain response, along with good stability and durability, allowing it to accurately monitor the movement of human body parts such as fingers, wrists, elbows, and knees. Additionally, owing to the enhanced ionic mobility at higher temperatures, this material also possesses excellent temperature sensing performance, enabling the fabrication of simple temperature sensors that can sensitively respond to temperature changes. This research provides new strategies for the practical applications of flexible electronic devices in fields such as wearable health monitoring and intelligent human-machine interaction.

Colloidal molecules exhibit unique electronic, optical, and magnetic properties owing to their molecular-like configurations and coupling effects, making them promising building blocks for multifunctional materials. However, achieving precise and controllable assembly of isotropic nanoparticles with high yields remains a great challenge. In this study, we present a synergistic strategy that integrates molecular dynamics simulations with interpretable machine learning to develop a programmable assembly system based on block copolymers and DNA-functionalized nanoparticles. Our simulation results reveal that block copolymer modification facilitates stepwise control over surface phase separation and nanoparticle coassembly, thereby enhancing structural stability and efficiently suppressing disordered aggregation of atom-like nanoparticles. Furthermore, we demonstrated that precise, controllable, and programmable assembly of colloidal molecules can be achieved through rational DNA sequence design. SHapley Additive exPlanations (SHAP) analysis identified key structural descriptors that govern assembly outcomes and elucidated their underlying mechanistic roles. This work not only deepens the understanding of colloidal molecule assembly mechanisms but also lays a theoretical foundation for the rational design of functional colloidal architectures in nanomaterial science.

Bacterial infections are becoming the second most common cause of death globally and have contributed significantly to morbidity and mortality. Cationic antibacterial polymers containing quaternary ammonium salts have been explored; however, it remains a key scientific challenge for current research to synergistically optimize the conformational relationships between structural surface features, active sites, and properties. In this study, a novel cationic copolymer microsphere with nano-multiple humps (CPMs-nMHs) was constructed through emulsion polymerization and self-assembly in EtOH/H₂O, with 3-methacrylamido-N,N,N-trimethylpropan-1-aminium chloride (MPAC) as the protruding functional component. Meanwhile, different hydrophilic monomers were adjusted to synthesize polymers with varying forms, which offered a significant research foundation for delving deeper into the impact of their morphology on performance. After being characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), dynamic light scattering (DLS), and thermogravimetric analysis (TG), the obtained CPMs-nMHs were applied to antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Surprisingly, the synthesized CPMs-nMHs exhibited excellent antibacterial performance, discovering that the antibacterial rates of up to 100%, while the activities of contrast copolymers were low. We considered that the dual cooperation of cationic structures and nano-multiple humps were responsible for the antibacterial capabilities. Taken together, cationic copolymer microspheres with nano-multiple humps provide a promising strategy for enhancing the antibacterial properties of cationic polymers.

The introduction of dynamic covalent bonds into the structure of epoxy resins can improve the degradation performance of the materials. But to a certain extent, it will affect the insulating properties of the resin, and how to balance the insulating properties and degradation performance has become an urgent problem. In this paper, the effects of different catalysts on the thermal-force-electrical properties of sorbitol-based resins were systematically investigated based on the dynamic ester bonding to construct the resin crosslinking network, and the biobased sorbitol glycidyl ether was used as the resin matrix. The experiments show that the resin system catalyzed by triethanolamine (TEOA) exhibits excellent comprehensive performance, which combines good thermal stability and mechanical properties with excellent electrical properties (breakdown field strength of 44.21 kV/mm and dielectric loss factor of 0.29%). In addition, chemical degradation tests were conducted on the resin systems with different catalysts, and the experiments showed that the produced resins could be degraded in benzyl alcohol and exhibited good degradation performance. This study provides a theoretical basis and technical path for the development of new bio-based electrical insulating materials with both high insulation and degradation properties, which is conducive to the popularization and application of bio-based resins in the field of electrical equipment.

Janus vesicles, unique nanostructures, have attracted significant attention for their diverse applications in biomedical and microfluidic systems. In practical micro-nano systems, flow and electric fields often coexist, and the perforation dynamics of Janus vesicles exhibit complex motion due to their synergistic effects. Studying Janus vesicle perforation dynamics under the combined influence of fluid flow and electric fields provides valuable insights into their applications in drug delivery, catalyst delivery, and controlled release. This study focuses on the perforation dynamics and directional motion of Janus vesicles in microchannels, emphasizing how electric field strength and charge distribution on the membrane influence vesicle migration, deformation, and trajectories. Results show that when electromagnetic forces and flow-driven forces align, increasing electric field strength promotes vesicle migration and perforation. Vesicle migration is correlated with charge distribution on the membrane, with broader distributions resulting in more pronounced migration. When electric field strength remains constant, charge distribution has little effect on vesicle deformation. Conversely, when electromagnetic forces and flow-driven forces oppose, increasing electric field strength inhibits vesicle migration. At a specific potential difference, charged vesicles cease movement before reaching the perforation site, indicating the critical potential for perforation. The study also reveals that the direction of the electric field significantly affects vesicle migration direction. Adjusting potential values at microchannel boundaries can control the directional movement of Janus vesicles. This research provides new insights into Janus vesicle behavior in complex environments and deepens understanding of their potential as drug carriers for delivery and targeted therapy.

The [2+2] photopolymerization of bisolefinic monomers is an important method for the synthesis of polymeric materials. However, these processes are usually carried out in solid states under the irradiation of high-energy UV light, while the corresponding [2+2] polymerization in solution has proved to be inefficient due to the lack of preassembly of the monomers. Herein, we demonstrate that the [2+2] polymerization of p-phenylenediacrylate monomers can be achieved in solution under visible light by employing energy transfer catalysis with 2,2′-methoxythioxanthone as a photocatalyst. Because no preassembly is required, this solution polymerization is applicable to p-phenylenediacrylate monomers with different ester groups, affording a series of cyclobutane-imbedded full-carbon chain polymers with high thermal stability, good solubility, and processibility. In addition, by virtue of the reversibility of the photo [2+2] cycloaddition, this [2+2] photopolymerization product can also undergo depolymerization to lower molecular weight polymers, suggesting the potential of this class of photopolymerization in the development of closed-loop chemical recyclable polymers.

The development of organic afterglow materials with high environmental stability and multi-mode luminescence remains a significant challenge in luminescent anti-counterfeiting. In this work, an organic luminescent molecule was encapsulated within polyacrylamide microspheres and embedded in a gold nanorod-doped, ferric ion-crosslinked hydrogel exhibiting upper critical solution temperature behavior. The obtained composites exhibited fluorescence, thermally activated delayed fluorescence, and phosphorescence. Through the application of extrusion or uniaxial stretching, the orientation of the gold nanorods was modulated, enabling polarization-dependent luminescence through transverse surface plasmon resonance absorption. At 300% uniaxial strain, the polarized fluorescence intensity difference at 520 nm reached 0.29. Furthermore, ultraviolet irradiation was employed to locally disrupt the orientation of the gold nanorods, resulting in depolarization within the irradiated regions. These areas displayed non-polarized fluorescence, while the non-irradiated regions retained both emission and fluorescence polarization characteristics. Localized imprinting was employed to modulate material thickness, thereby controlling the density of gold nanorods. Thinner regions exhibited weaker transverse localized surface plasmon resonance absorption, while thicker regions showed stronger absorption, enabling the coexistence of blue–green fluorescence and polarization patterns. Local humidification effectively reduced phosphorescence intensity, enhancing the material’s environmental responsiveness. The composite demonstrated excellent reversibility over multiple stretching–self-healing cycles and pattern-switching processes, highlighting its strong potential for multidimensional optical encryption and intelligent anti-counterfeiting applications.

The most widely used bisphenol A-type epoxy resin (DGEBA) in electrical engineering demonstrates excellent mechanical and electrical properties. However, the insoluble and infusible characteristics of cured DGEBA make it difficult to efficiently degrade and recycle decommissioned electrical equipment. In this study, a degradable itaconic acid-based epoxy resin incorporating dynamic covalent bonds was prepared through the integration of ester bonds and disulfide bonds, with itaconic acid as the precursor. The covalent bonding effects on the mechanical, thermal, electrical, and degradation characteristics were systematically evaluated. The experimental results revealed that the introduction of dynamic ester bonds enhanced the mechanical properties and thermal stability of the resin system, achieving a flexural strength of 141.57 MPa and an initial decomposition temperature T_5% of up to 344.9 °C. The resin system containing dynamic disulfide bonds exhibited a dielectric breakdown strength of 41.11 kV/mm. Simultaneously, the incorporation of disulfide bonds endowed the epoxy resin with remarkable degradability, enabling complete dissolution within 1.5 h at 90 °C in a mixed solution of dithiothreitol (DTT) and N-methylpyrrolidone (NMP). This research provides a valuable reference for the application of itaconic acid-based vitrimer with dynamic covalent bonds in electrical materials, contributing to the development and utilization of environmentally friendly electrical equipment.