Macromolecular Rapid Communications最新文献

Bithiazole-based poly(arylenevinylene) is synthesized via the Co-catalyzed hydroarylation polyaddition of N,N,N',N'-tetrahexyl-(2,2'-bithiazole)-4,4'-dicarboxamide with 2,7-diethynyl-9,9-bis(2-ethylhexyl)fluorene in a regioselective manner. The introduction of the 2,2'-bithiazole unit deepens the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels of the polymer compared to the analogous bithiophene-based poly(arylenevinylene). N-Methylation and N-oxidation of the thiazole moiety further deepen the HOMO and LUMO energy levels of the polymer, which is attributed to the enhanced electron-withdrawing effect. The N-oxidized polymer exhibits a high photoluminescence quantum yield and serves as an emitting material in an organic light-emitting diode, and its deep HOMO energy level efficiently restrains the trapping of holes in the host poly(vinylcarbazole) matrix.

Quantitative insertion of functionality into polymer chains via step-growth polymerization is challenging due to the random bimolecular reaction and relatively low extent of reaction. Herein, a copper-catalyzed azide-alkyne cycloaddition (CuAAC) step-growth polymerization with reaction-enhanced reactivity of intermediates (RERI) mechanism is applied for the precise insertion of degradable functions into the mainchain semifluorinated polymer and endowed it with controlled degradability. In this CuAAC polymerization, bis-alkynyl-terminated (A₂) monomer can be quantitatively consumed when the slightly excess of 2,2-bis(azidomethyl)propane-1,3-diyl bis(2-methylpropanoate) (BiAz, B₂) monomer with RERI effect is employed. The CuAAC copolymerization of o-nitrobenzyl ester-derived A₂ (A₂-ONB), fluorinated A₂ (A₂-F), and B₂ monomers produced the mainchain semifluorinated copolymers with tunable chemical composition and high molecular weight, along with the random and quantitative insertion of [A₂-ONB] units. These mainchain semifluorinated copolymers are capable of controlled degradation profile under ultraviolet radiation and can undergo complete degradation under basic condition. This work provided a simple approach for preparing mainchain semifluorinated polymers with controlled degradability.

Two-way shape memory polymers (2W-SMPs) are a class of smart materials and can undergo spontaneously reversible deformation after specific stimuli. It is crucial to develop 2W-SMPs to achieve precise control of two-way shape memory behavior without external forces and reveal their structure-property relationships. In this study, dual-crystalline phase crosslinked polymer networks based on poly(tetramethylene ether glycol) (PTMEG) and poly(ε-caprolactone) (PCL) are fabricated via thiol-ene click reactions. The networks with two independent melting temperatures are gained by adjusting the ratio of the two segments and the two-way shape memory is enabled using the temperature difference between the two phases. The effects of network composition, pre-tensile strain, and actuation temperature on the two-way shape memory properties are investigated and the two-way shape memory mechanism of dual-crystalline phase polymers is further elucidated. Among the various compositions of networks, PTMEG⁸-PCL² exhibits the optimal two-way shape memory properties, with the actuation strain of 24.25% and reversible strain of up to 10.35% at the actuation temperature and pre-stretch strain of 45 °C and 15%, respectively, which is potential for soft robotics applications. It is believed that this work guides the design of semicrystalline networks with two-way shape memory properties.

Helical polymer-containing bottlebrush polymers (BBPs) are a special and fascinating type of polymer. They possess bottlebrush topology and contain helical polymers as main chains (MCs) or side chains (SCs), thereby presenting interesting and fantastic properties, such as chiral amplification, circularly polarized luminescence, photonic crystal, and so on. This review mainly focuses on BBPs containing helical polymers of polypeptides, polyacetylenes (PAs), and polyisocyanides (PIs). Detailed summarizations are severally given to BBPs with helical polypeptides as MCs and SCs. Meanwhile, BBPs comprising helical PAs as MCs are fully discussed. What's more, BBPs consisted of helical PIs as MCs and SCs are described separately. In addition, BBPs with other helical polymers are briefly introduced, too. The authors hope this review will motivate more interest in developing helical polymers with complex topologies and fascinating properties, and encourage further progress in functional chiral materials.

This work introduces the semi-finished product FOIM, a neologism from FOIl and foaM, a phase segregated polyester urethane urea (PEUU) foam, which is synthesized from poly(1,6-hexylene adipate) diol, 4,4'-methylene diphenyl diisocyanate, polyethylene glycol and water as blowing agent. The PEUU is obtained by following a one-shot synthesis and is characterized by a hard/soft segment ratio of 1.06 and an open pore content of 78%. Differential scanning calorimetry reveals a melting peak at 45 °C and a crystallization signal at 14 °C, both of which are associated with the phase transitions of the soft segment. The glass transition temperature, which is determined as a local maximum within the tan δ using dynamic mechanical analysis, is 1 °C. During programming, the foam is heavily compressed at 60 °C. Once unloaded at 23 °C, a translucent foil, the FOIM, is obtained. When reheated to 60 °C, the foil switches back to the foam due to its pronounced shape memory properties. Intriguingly, the structure remains largely unaffected by the drastic deformation as indicated by buoyancy and heat transmission measurements. The ease of manufacture and functionality makes the technology attractive for applications, in which both low transport volumes and drastic shape changes are desired.

Back Cover: In article 2400727, Maryam Moradi and Prokopios Georgopanos present the synthesis of polyisoprene (PI) homopolymers, polyisoprene-polystyrene (PI-PS) block and random copolymers via RAFT-PISA polymerization in water. Using a poly(methacrylic acid) macroRAFT agent, PI and PI-PS copolymers with high monomer conversion are achieved. Thorough characterization indicated the successful synthesis, emphasizing PISA's scalability for producing tailored PI-PS copolymers with tailored-made molecular characteristics.

Front Cover: This cover image illustrates the integration of Hollow Yttrium-Oxide Spheres (HYSs) within a PDMS matrix, revealing their impact on passive radiative cooling. By embedding HYSs, the PDMS shows a notable increase in solar reflectivity and LWIR emissivity, effectively reducing solar heat gain while maximizing thermal radiation. Experimental validation and FDTD simulations confirm the optical benefits of HYS-infused PDMS, highlighting its viability for energy-efficient cooling. Our findings suggest that such composites are promising candidates for advanced passive cooling applications across diverse thermal management fields. More details can be found in article 2400770 by Yong Seok Kim, Youngjae Yoo, and co-workers.

Thermo-responsive polymers have emerged as a cutting-edge tool in nanomedicine, paving the way for innovative approaches to targeted drug delivery and advanced therapeutic strategies. These "smart" polymers respond to temperature changes, enabling controlled drug release in pathological environments characterized by high temperatures. By exploiting their unique phase transition, occurring at the lower or upper critical solution temperatures (LCST and UCST), these systems ensure localized therapeutic action, minimizing collateral damage to healthy tissues. The integration of these polymers into nanoparticles with hydrophilic shells and hydrophobic cores enhances their stability and biocompatibility. Furthermore, advanced polymer engineering allows precise modulation of LCST and UCST through adjustments in composition and hydrophilic-lipophilic balance, optimizing their responsiveness for specific applications. In addition to drug delivery, thermo-responsive nanoparticles are gaining attention in several fields such as gene therapy and imaging. Therefore, this review explores the chemical and structural diversity of thermo-responsive nanoparticles, emphasizing their ability to encapsulate and release drugs effectively. Second, this review highlights the potential of thermo-responsive nanoparticles to redefine treatment paradigms, providing a comprehensive understanding of their mechanisms, applications, and future perspectives in biomedical research.

Electrospinning is increasingly used as a staple technology for the fabrication of nano- and micro-fibers of different materials. Most processes utilize direct current (DC) electrospinning, and a multitude of DC-electrospinning tools ranging from research to commercial production systems is currently available. Yet, there are numerous studies performed on electrospinning techniques utilizing non-DC, periodic electric fields, or alternating current (AC) electrospinning. Those studies demonstrate the strong potential of AC-electrospinning for the sustainable production of various nanofibrous materials and structures. Although tremendous progress is achieved in the development of AC-electrospinning over the last 10 years, this technique remains uncommon. This paper reviews the AC-electrospinning concepts, instrumentation, and technology. The main focus of this review is the most studied, "electric wind" driven AC-electrospinning technique tentatively named alternating field electrospinning (AFES). The latter term emphasizes the role of the AC electric field's confinement to the fiber-generating electrode and the absence of a counter electrode in such an electrospinning system. The synopses of AFES process parameters, fiber-generating spinneret designs, benefits and obstacles, advancements in AC electrospun nano/micro-fibrous materials/structures and their applications are given, and future directions are discussed.