Polymer Chemistry最新文献

The rational design of charge transport mechanisms is crucial for constructing efficient catalysts with polymer heterojunctions (PHJs) for photocatalytic hydrogen production (PHP). In this study, a series of composites DBDSO/g-C₃N₄-x (x = 10, 15, 20, and 30) were synthesized by combining different proportions of g-C₃N₄ with DBDSO using the solvent dispersion method. The donor–acceptor (D–A) type conjugated porous polymer (CPP), named DBDSO, was synthesized through the Suzuki coupling reaction between dibenzothiophene-S,S-dioxide (DBTSO) and 4,8-di(thiophen-2-yl) benzo[1,2-b:4,5-b′] dithiophene (DBD). Optoelectronic measurements and theoretical simulations revealed that the formation of S-scheme PHJs facilitated efficient separation and transport of photo-generated carriers, resulting in a decrease in fluorescence lifetimes from 3.78 ns in pure g-C₃N₄ to 2.63 ns in the DBDSO/g-C₃N₄-15 composite. As a result, DBDSO/g-C₃N₄-15 exhibited significantly enhanced PHP performance compared to pure g-C₃N₄ catalysts without any precious metal co-catalyst addition, achieving an impressive hydrogen evolution rate (HER) of 80.75 mmol g⁻¹ h⁻¹. Additionally, DBDSO/g-C₃N₄-15 demonstrated good photocatalytic stability with an apparent quantum yield of 3.88% at a wavelength of 420 nm. This work presents a promising approach for enhancing the photocatalytic HER through rational structural design to regulate charge transfer.

Designing non-toxic, non-hemolytic, selective antimicrobials remains an important and challenging research problem. Herein, we report an affordable synthetic route to prepare a series of ten multifunctional polyethylene glycols (PEGs) via a cascade reaction approach involving aza-Michael polyaddition followed by post-polymerization modifications using triazolinedione-based click reactions. All polymers are characterized by NMR, IR, SEC, DSC and TG analyses. Antimicrobial and hemolytic studies reveal that structure plays a pivotal role in tuning the antimicrobial efficacy and selectivity (HC/MIC) of the functional PEGs. The selectivity (HC/MIC) reported for the best prototype (InPEG₇₀₀-C₁₂-TAD) is 129, 33 and 39 against P. aeruginosa, E. coli and S. aureus, respectively. Additionally, all the polymers are non-cytotoxic, as revealed by the MTT assay, and exhibit excellent antibiofilm activity.

The extensive development of polymer materials from fossil resources poses serious environmental challenges. Therefore, developing recyclable functional materials from biomass is crucial. Here, we confirmed the reversible exchange ability of dithioacetal bonds through a model compound exchange reaction. Crosslinked polydithioacetal (PDTA) was prepared via solvent-free polycondensation of biomass benzaldehyde and tetra-thiol monomers at room temperature. Self-healing and multi-mode recycling, including mechanical reprocessing, chemical recycling, and back-to-monomer recycling, were achieved under mild conditions with no mechanical performance reduction. The solid-state plasticity due to the dynamic nature of polydithioacetal endowed PDTA with reconfigurable shape memory capability, which ensured the flexible application of PDTA by allowing reconfiguration of its permanent shape and recovery route direction. Moreover, the activation temperature for shape memory can be facilely tuned by adjusting the crosslinking densities of PDTA to meet medical application needs. With its facile tunability, great hydrolytic resistance and biocompatibility, PDTA exhibited outstanding performance in a vascular stent demonstration experiment, in which a shrunken stent made of body temperature-responsive PDTA expanded and provided support within the vessel, showing the promise of PDTA as an environmentally and biologically friendly material for the implanted biomedical stent.

The development of materials from laboratory research to industrial production is a complex, challenging, but significant process. Polysulfamates have not been industrially available to date because of the absence of efficient and economical synthetic methods. Herein, a comprehensive process for the development of novel polysulfamate (PSA) materials from laboratory research to industrial manufacture is reported. PSAs were prepared with high molecular weight and narrow polydispersity through nucleophilic polycondensation between aryl bisphenols and disulfamoyl difluorides in the presence of an inorganic base. The polymerization process was stable in moisture and air. The industrial production of PSAs was achieved on 100 kg scale with the assistance of a cooperative factory for the first time. The PSAs displayed excellent solvent tolerance, acid/base resistance, thermal stability, machinability and mechanical properties, which were promising for their application in the area of engineering plastics, as well as high-performance resins.

Herein, a new type of supramolecular cross-linker was successfully constructed through host–guest interactions between the cationic pillar[5]arene and a sulfonate-functionalized acrylate, leading to the formation of a supramolecular polymeric hydrogel using photopolymerization of acrylamide, acrylic acid and twisted intramolecular charge transfer fluorescent moieties. This obtained hydrogel is a novel multicolor fluorescent functional hydrogel integrating pH-responsiveness, self-healing, electrical conductivity, and stretchability. Moreover, this hydrogel can effectively detect iron ions (Fe³⁺) through fluorescence.

In this study, a primary amine-terminated star-shaped polystyrene (PS) was synthesized using an Activators Regenerated by Electron Transfer Atom Transfer Radical Polymerization (ARGET ATRP) protocol, yielding products with low dispersity (<1.2) and molar masses in the range of 2 to 12 kDa. The influence of the trifunctional initiator's reactivity on the resulting polymer topology was investigated. The bromo-terminated PS was efficiently converted to its azide-terminated counterpart as confirmed by online ATR FT-IR and NMR spectroscopy. The targeted amine-terminated PS was then obtained by a Staudinger reduction of the azide groups using tributylphosphine. To assess the applicability of these novel amine-terminated PSs as well-defined trifunctional crosslinking agents, traditional epoxy thermoset networks and covalent adaptable networks (CANs) were synthesized using diepoxides or diacetoacetates, respectively. The resulting materials exhibited excellent thermal resistance, attributed to the high PS content. Moreover, by making use of the option of tuning the molar mass of such macromolecular crosslinkers, the network's crosslinking density could be tailored, enabling control over swelling degree, glass transition temperature, and, in the case of the obtained vinylogous urethane vitrimers, even reprocessability.

This study introduces a novel approach combining reversible addition–fragmentation chain transfer (RAFT) polymerization and hetero-Diels–Alder (HDA) reactions to efficiently synthesize hyperbranched polymers (HBPs) with controlled topology. The traditional AB_n monomer methods for creating HBPs face limitations due to random polymerization and the risk of gelation. By optimizing the AB_n system into an AB_x macromonomer framework, this new RAFT–HDA method enables controlled polymerization, reducing intramolecular cyclization and topological defects and broadening the range of possible polymer architectures. Additionally, more readily available and widely used novel dienes and dienophiles have been identified for the HDA reaction. The versatility of this approach was demonstrated by synthesizing a variety of HBPs with different branching degrees and molecular weights, which were thoroughly characterized by NMR, FTIR, GPC, and DLS techniques. This study provides a robust and efficient pathway for synthesizing complex polymer structures, demonstrating that the RAFT–HDA strategy enables the production of well-defined hyperbranched polymers with significant potential for applications in nanomaterials, biomedicine, and advanced functional materials.

Unlike landfill biodegradation, thermal recycling, and downcycling, the adopted “depolymerization–polymerization” closed-loop recycling strategy offers a more sustainable, resource-efficient, and environmentally protective solution for waste polymer treatment. However, selective depolymerization of aliphatic polyesters remains challenging due to their unclear depolymerization kinetic characteristics and mechanisms. In this study, polycaprolactone (PCL) was thermally depolymerized into ε-caprolactone (ε-CL) monomers catalyzed using stannous octanoate (Sn(Oct)₂), and the ε-CL was subsequently repolymerized through ring-opening polymerization to regenerate PCL. Notably, the depolymerization conversion for ε-CL monomers reached 98.1% in 4.5 hours, with a linear decrease of the PCL macromolecule. Density functional theory (DFT) calculations revealed that the relaxed force constant of the C–O bond in the ester group decreased from 5.46 to 5.08 N cm⁻¹ due to electron density redistribution by Sn(Oct)₂ coordination, facilitating efficient first-order depolymerization through a “chain-end backbiting” strategy. Furthermore, the regenerated PCL (re-PCL) retained comparable molecular weight, mechanical, thermal, and crystallization properties to those of pristine PCL, with a tensile strength of 28.4 MPa and 913% elongation at break. This closed-loop recycling strategy provides an innovative approach for the sustainable recycling of waste polymers.