Macromolecular Rapid Communications最新文献

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.

Front Cover: Racemic octahedral metal complexes with Δ and Λ chirality have been reported as the first octahedral metallomesogens to exhibit a micellar cubic liquid crystal phase. Furthermore, quasi-racemic mixtures, a 1:1 mixture of Δ -Ru-Cn and Λ -Ir-Cn, also exhibit the CubM phase and display unique vibrational circular dichroism signals that are not observed in pure enantiomers. More details can be found in the Research Article by Go Watanabe, Mitsuo Hara, Jun Yoshida, and co-workers (DOI: 10.1002/marc.202500485).

The synthesis of high-performance hydrogel adhesives often relies on complex, multi-component systems, complicating their preparation and application. To overcome these limitations, we report a thermosensitive nanogel adhesive (NGA) via a facile one-step precipitation polymerization of N-isopropylacrylamide (NIPAM) and 3-acrylamidophenylboronic acid (AAPBA). This NGA functions as a simple adhesive, forming stable bonds with hydroxyl-rich substrates without requiring additional curing steps. The resulting nanogel exhibits dual sensitivity to temperature and pH, undergoing reversible changes and gelation under specific conditions. Mechanical interfacial bonding tests of hydrogel substrates reveal that a minimal volume of 15 µL of the NGA dispersion achieves a shear strength of 7.0 ± 1.4 kPa and a tensile strength of 15.7 ± 4.2 kPa. Furthermore, the adhesion performance can be precisely tuned by controlling the nanogel particle size, dispersion pH, and concentration. Biocompatibility assessments confirm excellent hemocompatibility and cell viability. This work not only presents a robust and tunable nanogel adhesive platform but also establishes a general model for the design of functional nanogel-based adhesives, significantly expanding their potential applications.

Tropolone is one of the non-benzenoid aromatic compounds and consists of a seven-membered ring with 6π electrons. Although its photophysical properties involving light absorption and photoluminescence (PL) spectra have been investigated, there are limited number of systematic studies on unveiling structure-photophysical property relationships because its absorption and luminescence are relatively weak. We have recently reported that boron complexes with tropolone derivatives and their π-conjugated polymers exhibit enhanced absorption and PL properties derived from the significant electron-accepting ability originating from the seven-membered ring. Herein, we attempt to reveal the versatility of polymerization/oligomerization for amplifying photophysical properties of tropolone-based boron complexes. In this study, we synthesized the boron complexes with arylaminotropones, where one of the oxygen atoms of tropolone is converted to nitrogen, offering a handle to tune properties, and examined the electronic properties of its oligomers as well as small molecules. It was found that amination of the coordination site caused the bathochromic shifts of absorption and PL bands with a decrease in PL quantum yield (PLQY). Moreover, compared to boron tropolonate derivatives, the absorption and PL spectra showed a bathochromic shift, and PLQY was improved by oligomerization, indicating that the oligomerization might enhance the opportunity of tropolone-based compounds for photophysical applications.

Heteroatom incorporation is a general strategy toward advanced polymer properties. We report here efficient synthesis of polymers containing, site-specifically, at least four different heteroatoms (O, N, S, F) by copolymerization of isothiocyanate (ITC) and trifluoropropylene oxide (TFPO). Unlike the regular non-fluorinated epoxides for which Lewis pair catalysts are needed, the superior activity of TFPO allows the use of only organobases, even the relatively mild ones, to reach high/complete monomer conversion in hours at room temperature and low catalyst loadings (0.01-0.1 mol.%). With optimal initiator structure and monomer feed ratio (1/1), alternating copolymers, i.e. fluorinated polythioimidocarbonates (^FPTCs), with controlled molar mass and low dispersity are obtained. Copolymerization with alkyl and allyl ITCs are remarkably more chemoselective, which is ascribed to the alleviated nucleophilicity of the oxyanionic species and expedited S-to-O crossover. While thermostability of the aromatic PTC is evidently improved and adhesive strength unaffected by the CF₃ groups, depolymerization becomes much easier under basic conditions, selectively forming a five-membered cyclic thioimidocarbonate.