Macromolecular Rapid Communications最新文献

The development of polymer electrolytes is a promising strategy for increasing the safety and performance of lithium batteries. In particular, gel polymer electrolytes (GPEs) are closest to replacing conventional liquid electrolytes due to their properties from the incorporation of plasticizers and conductors into polymers. One family of these compounds, ionic liquids (IL), has the ideal range of properties for reducing the risk of fire, leaks, and toxic by-products. In this work, poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) copolymer was used to synthesize a GPE with lithium salt and 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide (IL), evaluating the effect of different solvents on the final properties of the material, such as thermal stability, crystallinity, microstructure and conductivity. The addition of IL was responsible for a reduction in the crystallinity of PVDF-HFP from an average of 31% to 11%, and a diminution in its thermal stability (T_2%) from 435°C to 350°C. Membrane microstructure was dependent on the solvent used, ranging from completely uniform with acetone to granular with dimethylformamide or dimethylacetamide. The dimethylacetamide electrolyte had the highest conductivity (0.43 mS cm^-1), while the N-methylpyrrolidone electrolyte showed better interaction with metallic lithium.

Detecting nanoplastic particles in environmental samples and biological tissues remains a significant challenge, especially in view of newly emerging polymers, not yet commercially exploited. Fluorescent labeling provides a tagging strategy to overcome this limitation by reducing the detection limit of individual particles, especially for small-sized particles. We present a method for producing labeled nanoparticles (NP/MP) of poly(ethylene terephthalate) (PET) and poly(ethylene furanoate) (PEF), tagged with Alexa Fluor 633 or Alexa Fluor 647. Our preparations used mechanical grinding or solvent-based approaches (confined impinging jet mixing, ((CIJ, precipitation), generating particles with hydrodynamic diameters of 200-700 nm, displaying long-term stability in water of up to 57 days. Stable suspensions with concentrations of the particles ranging from 10 µg/mL (surfactant-free, by solvent mixing) to 5.88 mg/mL (precipitation, containing surfactant) were generated with zeta-potentials from -5 to -50 mV. Characterization of the nanoparticles by SEC, DSC, and XRD showed no significant changes in molecular weight, thermal behavior, or crystallinity via the solvent-based methods, compared to the pristine polymer, highlighting their suitability for producing standardized nanoparticle dispersions. Fluorescence spectroscopy of the Alexa-dye-labeled particles confirmed the successful incorporation of the Alexa dyes, so improving monitoring of their biological profiles of the PEF-MP/NPs. s-SNOM (near field imaging) could identify individual PEF-particles sized ∼200 nm by direct imaging.

The influence of molecular chain entanglement on the mechanical performance of polycarbonate (PC) at superhigh strain rates has been investigated, which is valuable for its safety applications like window glazing. The mechanical testing results across a wide strain rate range (0.01-100 s^-1) show that toughness increases with strain rate, but significant deterioration of stiffness and toughness occurs at 100 s^-1. This phenomenon is, for the first time, observed in real time using digital image correlation (DIC), revealing severe stress concentration and strain localization at 100 s^-1. Nevertheless, we find this deterioration is significantly suppressed by the high entanglement density. It strengthens the strain hardening regime and dynamic mechanical analysis (DMA) is showing that both loss modulus and tan δ values increase with entanglement density in the β-relaxation region, indicating enhanced energy dissipation, which may be the underlying origin of the improved ability to resist deformation. This work is providing fundamental insights into tailoring entanglement networks to suppress energy absorption deterioration under extreme deformation conditions.

The morphology of conjugated polymers plays a significant role in determining their charge transport characteristics. In this study, we investigate the hole transport properties of a crystalline conjugated polymer (PBDB-T) blended with an insulating polystyrene (PS) with different molecular weights and weight fractions. Surprisingly, PBDB-T/PS blend films exhibit enhanced hole mobility compared to the PBDB-T neat films. This enhancement is strongly correlated with morphological changes in PBDB-T, which are dependent upon the molecular weight of the PS matrix. Specifically, blending with low molecular weight PS promotes homogeneous mixing and increased crystallinity, leading to a moderate improvement in the charge transport. In contrast, blending with high molecular weight PS induces phase separation, resulting in the formation of PBDB-T rich domains. These domains enable efficient charge percolation through localized aggregation and by reducing trap densities. These findings underscore the dual role of insulating polymers in modulating phase-separated structures and charge transport pathways in conjugated polymer systems. The results demonstrate that morphology engineering via polymer blending offers a simple yet powerful strategy for optimizing charge transport, which in turn offers promising avenues for the advancement in flexible optoelectronic devices.

Compared with the extensively studied radical and cationic ring-opening polymerizations (ROP), the behavior of thionolactones under anionic conditions (aROP) has long remained unclear, only recently coming to light through key breakthroughs. The aim of this Perspective is threefold: (1) to highlight the importance of sulfur-containing polymers and the historical challenges in accessing them; (2) to summarize state-of-the-art initiating systems that enable precise control over molecular weight and dispersity while allowing complete selectivity between thiocarbonyl retention and S/O isomerization; and (3) to offer perspectives on the broader development of thionolactone aROP, with a focus on mechanistic understanding, monomer design, and copolymerization strategies.

Replacing fossil-derived carbon black (CB) with sustainable fillers is a major challenge in elastomer design. Here, we demonstrate that a green-solvent casting method using 2-methyltetrahydrofuran (2-MeTHF) enables submicron-scale dispersion (∼200 nm) of lignin within a styrene-butadiene rubber (SBR) matrix without chemical modification. Unlike conventional melt-mixed composites that contain micron-scale agglomerates, AFM-IR chemical mapping directly visualized homogeneous lignin domains and rubber phase that could not be separated by SEM, revealing a fine filler network responsible for mechanical reinforcement. Dynamic mechanical analysis showed that the 20 vol% lignin composite achieved a storage modulus and Payne effect comparable to those of SBR/CB composites, confirming the formation of a percolated filler network. Moreover, the reduction of tan δ at 60°C indicated lower hysteresis loss and the potential for improved rolling resistance. These findings established that processing-induced nanoscale dispersion, rather than chemical surface modification, governs the reinforcement efficiency of bio-based fillers. The present approach offers a simple, scalable, and environmentally benign route to valorize lignin as a functional reinforcing phase in high-performance and sustainable elastomers, paving the way for next-generation tire and flexible material applications.