ACS Macro Letters最新文献

A simple and effective strategy to obtain solid-state multicolor emitting materials is a particularly attractive topic. Nonconventional/nonconjugated polymers are receiving widespread attention because of their advantages of rich structural diversity, low cost, and good processability. However, it is difficult to control the molecular conformation or to obtain the crystal structure of amorphous molecules, which means it is a challenge to obtain nontraditional polymeric materials with multicolor emission. In this work, a polyurethane derivative (PUH) with red-shifted emission was synthesized by a simple one-pot polymerization reaction. By exploiting the aggregation-induced luminochromism of PUH, a series of plastic films with tunable emission from blue to orange, and white-light emission, was obtained by doping different amounts of PUH into poly(methyl methacrylate) (PMMA), thereby changing the aggregation degree of PUH. This work demonstrates the excellent promise of polyurethane derivatives for the simple fabrication of large-scale flexible luminescent films.

Utilizing the unique properties of fluorine substitution is an effective strategy for constructing highly functional materials. Here, we synthesized a novel copolymer composed of [1.1.1]propellane and perfluoro(propyl vinyl ether) (PPVE), rich in alternating sequences. The spin-coated copolymer film was amorphous, and its surface exhibited an extremely low surface free energy (γ). The γ value was lower than that of polytetrafluoroethylene despite containing only 40 mol % PPVE units. This can be attributed to the cancellation of the C–F dipole moments by the entirely random orientation of the fluorine units.

Developing effective recycling pathways for polyolefin waste, enabling a move to a circular economy, is an imperative that must be met. Postuse modification has shown promising results in upcycling polyolefins, removing the limitation of inertness, and improving the final physical properties of the recycled material while extending its useful lifetime. Grafting of maleic anhydride groups to polypropylene is an established industrial process that enhances its reactivity and provides a convenient route to further functionalization and upcycling. In this work, maleic anhydride grafted polypropylene was hydroxylated and subsequently cured with a diisocyanate to form a thermoset polyurethane (PU). The crystal structure (unit cell and lamellar structure) of the polypropylene (PP) was preserved in the PU. At room temperature, the PU showed a high modulus due to the crystallization behavior of the PP; upon increasing the temperature above the melting temperature, the modulus decreased to a rubbery plateau, consistent with formation of a network. The resulting PU showed a higher glass transition temperature and lower degree of crystallinity than its PP predecessor due to the crosslinked nature of the polymer. The mechanical integrity of the PU was maintained through several reprocessing cycles due to the melt processability enabled by the presence of a urethane exchange catalyst. This functionalization and upcycling route thus offers a promising alternative to repurposing PP waste in which the creation of melt-processable thermoset polymers expands applications for the materials.

Polymeric nanocarriers have attracted significant attention in the field of anticancer drug delivery due to their unique advantages. However, designing nanocarriers that can maintain stability in the bloodstream while achieving specific drug release within tumor cells remains a major challenge. To address this issue, constructing reversible cross-linked polymeric nanocarriers that are sensitive to the intracellular reducible glutathione (GSH) characteristic of the tumor microenvironment is a promising strategy. Based on this, we designed and synthesized two novel six-membered bicyclic carbonate monomers containing disulfide (DSBC) and trisulfide (TSBC) bonds. Through a one-step ring-opening polymerization, a series of reduction-sensitive polycarbonate copolymers (i.e., PEG–PDSBC and PEG–PTSBC) were prepared, and doxorubicin (DOX)-loaded nanoparticles were fabricated using a nanoprecipitation method. The in vitro drug release behaviors of these nanoparticles were systematically investigated. The results showed that these polymers, due to the cross-linked structure formed by the ring-opening polymerization of their bicyclic monomers, could self-assemble into stable nanoparticles. Under different concentrations of glutathione, DOX-loaded PEG–PTSBC nanoparticles demonstrated faster drug release, indicating more optimized intracellular drug release properties. Further cytotoxicity experiments revealed that both types of blank nanoparticles exhibited good biocompatibility with the 4T1 and NIH-3T3 cells. Fluorescence microscopy and flow cytometry results further indicated that DOX-loaded PEG–PTSBC nanoparticles released more drugs in 4T1 cells, significantly inhibiting tumor cell growth compared with DOX-loaded PEG–PDSBC nanoparticles, with no noticeable difference in NIH-3T3 normal cells. In conclusion, this study suggests that trisulfide cross-linked polycarbonate-based nanocarriers hold promise as an anticancer drug delivery system that combines stability in the bloodstream with specific intracellular drug release, offering new insights for the development of novel, efficient, and safe anticancer nanomedicines.

Herein, the long-standing challenge of the ring-opening aminolysis of CO₂-derived tetrasubstituted cyclic carbonates at room temperature (r.T) is overcome under catalyst-free conditions. Molecular design of the cyclic carbonate by substitution of an alkyl group by a thioether unlocks quantitative conversion at r.T and ensures total regioselectivity toward highly substituted oxazolidone scaffolds. An in-depth rationalization of the high reactivity of these cyclic carbonate structures and of the aminolysis reaction mechanism is provided by a computational study supporting experimental observations. The high efficiency of the reaction is then translated to the deconstruction of high-performance thermoplastics containing tetrasubstituted cyclic carbonate linkages to deliver building blocks that are reused for designing recyclable thermosets bearing dynamic N,S-acetal linkages.

Herein, we present a highly efficient method for synthesizing multifunctional polymers. This method involves the sequential postpolymerization modification (PPM) of a highly reactive aldehyde polymer. We introduce an allylic alcohol functionality into the polymer backbone via Barbier-type allylation, a process facilitated by easy-to-handle indium(0) powder. This step enables the formation of orthogonal pendants, secondary alcohol, and terminal alkene, which can be further functionalized through esterification and thiol–ene click reactions. All of these processes are carried out under mild conditions, ensuring high efficiency and a wide range of functional groups. Our study underscores PPM’s operational simplicity and versatility in developing advanced polymer materials and expanding the scope of multifunctional polymer design.