Macromolecules最新文献

{"title":"Well-Defined Chain-End Functionalized Polyethylenes with Different Macromolecular Architectures","authors":"Saibal Bhaumik, Nikolaos Patelis, Konstantinos Ntetsikas, Yun-Long Hou, Kenneth L. Kearns, Kelly Setula, Saurav S. Sengupta, Timothy J. Person, W. H. Hunter Woodward, Stacey Saba, Sara Livazovic, Nikos Hadjichristidis","doi":"10.1021/acs.macromol.5c01760","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c01760","url":null,"abstract":"This study reports the synthesis of a wide library of α,ω-dihydroxy, ω-hydroxy (linear and 3-arm star), and ω-amine functionalized, as well as nonfunctionalized polyethylenes (linear and 3-arm star) via diimide hydrogenation of the corresponding polybutadiene precursors. All polyethylenes were synthesized using anionic polymerization high-vacuum techniques followed by suitable postpolymerization reactions and hydrogenation. Molecular characterization confirmed low 1,2-microstructures in the polybutadiene precursors, resulting in linear low-density polyethylene (LLDPE)-like architectures, after hydrogenation. Additionally, perfectly linear ω-hydroxy polymethylene (equivalent to polyethylene) samples, resembling high-density polyethylene (HDPE) structures, were synthesized via polyhomologation. Thermal analysis and X-ray diffraction measurements showed reduced crystallinity in the functionalized samples, likely due to hydrogen-bonding effects that disturb the crystalline packing. In contrast, the polyethylene synthesized via polyhomologation exhibited higher crystallinity values, resembling the structure of high-density polyethylene (HDPE). These findings underscore the influence of functional groups on polyethylene properties, motivating future studies on their thermal and dielectric behavior.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"49 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145025858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Weld Formation Between Polymer Films Prepared at Different Temperatures: Insights from Molecular Dynamics Simulations","authors":"Mauro L. Mugnai, Jonathan E. Seppala, Peter D. Olmsted","doi":"10.1021/acs.macromol.5c00569","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c00569","url":null,"abstract":"Inspired by Fused Filament Fabrication (FFF) Additive Manufacturing (AM), we use Molecular Dynamics (MD) simulations to investigate the early stages of the formation of the weld between two polymer films prepared at different temperatures – one above and one below the dilatometric glass transition temperature. We identify three stages of welding: (i) surface approach and formation of the initial contact, (ii) surface adjustment, and (iii) interdiffusion. Surface interactions affect film roughness, polymer conformation, and interfacial temperature during the initial stage. As the two layers come into contact, heat transfer equilibrates the system in an asymmetric way: the hot film cools down more slowly than the cold film heats up. When the films are allowed to exchange heat with the environment, most of the effects of the temperature difference at the interface terminate during the initial surface adjustment, before polymer interdiffusion begins at around the bulk Rouse time. However, if the films are isolated, the onset of interdiffusion occurs earlier for films prepared at different temperatures compared to films prepared at the same temperature. This indicates the importance of thermal relaxation across the interface between welding films, and suggests mechanisms to improve the weld strength.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"45 4 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145025861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Soluble Hydroxy-Containing Poly(benzoxazole-benzimidazole-imide)s for Membrane-Based H2/CO2 Separation","authors":"Fan Hu, Jinpeng Luo, Shichao Feng, Liangqiang Wei, Shinji Ando, Yinhua Wan, Yongbing Zhuang","doi":"10.1021/acs.macromol.5c01671","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c01671","url":null,"abstract":"Conventional polyimide (PI) membranes exhibit low H₂/CO₂ selectivity (≤3.1). To address this limitation, this study synthesized a novel diamine monomer, 5-amino-2-(4-hydroxy-3-aminobenzene)-benzoxazole (OH-BOA), specifically designed with benzoxazole and hydroxyl functionalities. Subsequently, OH-BOA and its structural counterpart 5-amino-2-(4-hydroxy-3-aminobenzene)-benzimidazole (OH-BIA) were copolymerized with pyromellitic dianhydride (PMDA) to yield four hydroxy-functionalized poly(benzoxazole-benzimidazole-imide)s (OH-CoPIs). These OH-CoPIs exhibited good solubility, robust mechanical properties (tensile strength ≥ 114.9 MPa), high glass transition temperatures (T_g > 400 °C), and low coefficients of thermal expansion (CTE ≤ 28.3 ppm/K). Notably, they achieved a significantly enhanced H₂/CO₂ selectivity of up to 12.2, surpassing the commercial Matrimid 5218 (3.1) by 4-fold. Systematic evaluation revealed that increasing benzoxazole content reduced the CTE while enhancing tensile strength, Young’s modulus, and H₂/CO₂ selectivity. The thermally rearranged membrane (TR-40CoPI-400, 400 °C) achieved high H₂ permeability (26.00 Barrer) with optimal selectivity (7.6) and exceptional CO₂ plasticization resistance. The synergistic integration of benzimidazole, benzoxazole, and hydroxyl groups enables high-performance PI membranes for H₂/CO₂ separation.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"64 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145009135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ionization and Chain Size of Weak Polyelectrolytes in Semidilute Regime","authors":"Lucie Nová, Miroslav Štěpánek, Iryna Morozova, Zdeněk Tošner, Filip Uhlík","doi":"10.1021/acs.macromol.5c00895","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c00895","url":null,"abstract":"We present the relations between chain size, correlation length, and degree of ionization for linear weak polyelectrolytes in the semidilute regime. In the semidilute regime, SAXS provides the correlation length(s), ξ, but cannot provide the chain size characteristics. Similarly, pH measurements and the Henderson–Hasselbalch equation do not yield a realistic estimation of the degree of ionization of weak polyelectrolytes in the semidilute regime. On the other hand, simulations provide all these: end-to-end distance R_ee, radius of gyration R_g, degree of ionization α. We measured SAXS profiles of poly(acrylic acid) at various degrees of neutralization in the semidilute regime. We compared the experimental scattering curves with their counterparts from coarse-grained Hamiltonian Monte Carlo simulations in terms of the position of the polyelectrolyte peak, q*, and the fractal dimension, d_f. Regarding q*, our results not only are in mutual agreement but also obey the previously predicted scaling relations in the limit of high α values. In particular, we obtained R_ee ∝ ξ^0.3 for α > 0.3, R_ee ∝ α ^4/7 for 0.1 < α < 0.5, R_ee ∝ α^1/7 for α > 0.5 and R_ee approximately constant for very low values of α.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"27 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145009136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Precision Library Synthesis of PS–PMMA Block Copolymers with Discrete Junctions: Cooperative Self-Assembly to Break the Phase-Separation Limit","authors":"Suguru Sonobe, Tomoka Yoshimura, Shinsuke Maekawa, Ryota Uehara, Teruaki Hayakawa, Makoto Ouchi","doi":"10.1021/acs.macromol.5c01439","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c01439","url":null,"abstract":"We achieved the formation of a lamellar structure via phase separation of a polystyrene-poly(methyl methacrylate) (PS–PMMA) block copolymer (BCP) with a relatively low molecular weight [M_n ∼ 11,400, DP_n = 42 (PS), 69 (PMMA)] through the introduction of a discrete bis-urea component at the junction. This is a remarkable achievement, given that the theoretical minimum molecular weight required for phase separation of PS–PMMA BCPs is 28,000. A library synthesis of the junction structure, while keeping the molecular weights of the two polymer segments fixed, led to the discovery of this unprecedented behavior. A cyclohexylene spacer between the urea bonds is crucial for affording an ordered structure, and even a slight change of the spacer structure resulted in the formation of a disordered structure. Fourier-transform infrared spectroscopy analyses revealed that hydrogen-bonding interactions between the bis-urea junctions are indispensable for a successful phase separation. The hydrogen-bonding interactions at the junction cooperate with the phase separation of the BCP to stabilize transient lamellae formation during thermal annealing at 150 °C. Further evidence for this cooperative self-assembly process was obtained from experiments with blends of junction-matched/mismatched BCPs.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"17 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145009145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recyclable Strong Tough Ionogels via the Synergy of Solvent-Induced Cross-Linking and Chain Entanglement","authors":"Wenhao Li, Min Li, Menghan Pi, Huanwei Shen, Shilei Zhu, Wei Cui, Rong Ran","doi":"10.1021/acs.macromol.5c01293","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c01293","url":null,"abstract":"Ionogels are promising soft materials for diverse applications due to their exceptional ionic conductivity, thermal stability, and nonvolatility. However, conventional ionogels often suffer from compromised mechanical properties due to the plasticizing effect of ionic liquids, limiting their suitability for load-bearing applications. In this study, we present a counterintuitive strategy in which a small amount of ionic liquid severs not as a plasticizer but as a key structural modifier. On one hand, the ionic liquid facilitates hydrogen bond-mediated cross-linking, eliminating the need for chemical cross-linkers and enabling full recyclability. On the other hand, its limited content allows for dense chain entanglements within the polymer network, significantly enhancing mechanical robustness. This interplay yields ionogels with extraordinary mechanical properties, including a fracture stress of 7.8 MPa, fracture toughness of 54 kJ/m², and a Young’s modulus of 46 MPa, while also imparting outstanding stretchability (780%) and broad-spectrum viscoelasticity (10^–6–10⁴ Hz). As a proof of concept, the ionogel was assembled into a soft armor, demonstrating exceptional noise-damping and impact-resistant capabilities. This work provides insights into harnessing solvent-mediated interactions to engineer mechanically robust and sustainable ionogels for advanced applications.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"12 18 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145007135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Critical Temperature–Pressure Window for Attaining a Giant Piezoelectric Voltage Coefficient in Poly(vinylidene fluoride)","authors":"Shu-Gui Yang, Zheng-Yang Zhang, Liang-Qing Zhang, Jiaming Cui, Jun Lei, Feng Liu, Xiang-bing Zeng, Goran Ungar","doi":"10.1021/acs.macromol.5c01590","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c01590","url":null,"abstract":"Polymeric piezoelectric sensors are increasingly important in the context of advancing artificial intelligence and soft robotics. It is known that the electric response to mechanical stress of poly(vinylidene fluoride) (PVDF) increases with increasing fraction of noncentrosymmetric (or “polar”) β and γ crystal forms (X_β+γ), as well as with increasing fraction of extended-chain crystals (F_ECC). Here, we describe a temperature–pressure (T–P) window for achieving both high X_β+γ and high F_ECC through intervention of the high-pressure hexagonal mesophase. Importantly, we show that high X_β+γ and F_ECC can be achieved under considerably milder conditions, 100 °C and 100 MPa below the equilibrium T–P range of the mesophase. By rapidly pressure-quenching the melt significantly below the triple-point temperature, direct melt-crystallization is bypassed, and the system enters a heavily superpressed and supercooled metastable range of the mesophase. This enables the lamellae of the mesophase to grow and thicken, subsequently transforming to largely extended-chain β and γ forms. Thus, a T–P processing window opens up, leading to a marked increase in the piezoelectric response. This way, we achieved a record PVDF piezoelectric voltage constant g₃₃ of 1.35 V·m·N^–1. Moreover, the chain extension involved also raises the melting point of the polymer by ∼30 °C, making the sensors usable at higher temperatures. This study offers guidance for the development of high-sensitivity PVDF-based piezoelectric sensors for applications across a broad temperature range.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"41 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145007131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Translational Dynamics and Structural Enhancement Effect in High-Temperature Supramolecular Systems of Asparaginyl Low-Molecular-Weight Gelators and Propylene Carbonate","authors":"Farooq Ahmad, Natalia Bielejewska, Dawid Pakulski, Michał Bielejewski","doi":"10.1021/acs.macromol.4c03225","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c03225","url":null,"abstract":"Chemical engineering paves the way for the design of new materials with targeted properties. Supramolecular chemistry allows the creation of molecular assemblies from small molecules based on noncovalent interactions between the components, e.g., hydrogen bonds and dispersive or electrostatic forces, leading to the templating of self-assembly structures. The reversible bonding interaction allows for optimization of the final structure and enhancement of the properties. In this study, we have used this approach to design and prepare supramolecular membranes that work at temperatures exceeding the 100 °C limit. The system is based on low molecular weight gelators (LMWGs), which provide versatility of compositions, flexibility, tunable properties, and improved sustainability. LMWG-based systems mostly exhibit gel-like features, offering an alternative with enhanced responsiveness, self-healing abilities, recyclability, and viscoelastic properties. In this context, we developed a gel-like membrane using an aspartame derivative as the LMWG and propylene carbonate as a liquid phase to prepare systems that can solidify carbonate solvents widely used in the chemical industry. The TGA/DTG and DSC thermal analyses were used to evaluate the system’s performance at high temperatures. The intermolecular interactions, gelation mechanism, and solvent dynamics were examined using different nuclear magnetic resonance methods. The microstructures of the obtained membranes were studied by using a fluorescence confocal scanning microscope. The obtained results have shown that the designed systems subjected to proper thermal processing routes can achieve enhanced structural stability, allowing them to work continuously at temperatures exceeding the 100 °C limit. The NMR studies showed that translational dynamics of the solidified liquid remain comparable to those observed for the liquid state, preventing the bulk flow simultaneously and compensating for the thermal convection effects. The performed matrix analysis showed how the self-assembled supramolecular aggregates of the gelator evolve with the membrane composition. We have demonstrated that the investigated membranes exhibit efficient self-healing effects above some concentration threshold.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"16 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145007163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Beyond Simplifications: Overlooked Physics of Macromolecular Behaviors in Living Cells","authors":"Miho Yanagisawa, Kei Fujiwara","doi":"10.1021/acs.macromol.5c00706","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c00706","url":null,"abstract":"Simplifications are key to understanding the complex physical behaviors of biomacromolecules within living cells. However, in cell-sized spaces─micrometer-scale compartments enclosed by lipid membranes─the molecular organization, phase behavior, and reaction dynamics are influenced by confinement, high molecular concentrations, and membrane interfacial effects. Studies have shown that these factors, which are often overlooked or ignored during simplification, are critical for deducing the physics of intracellular processes. This perspective highlights the recent findings on the molecular behaviors of cell-sized spaces and emphasizes the need to consider cell-sized space effects, molecular diversity, and nonequilibrium dynamics to elucidate the physics of living cells. A deeper understanding of these fundamental principles bridges the gap between molecular biology and physics. In addition, it will refine our understanding of cellular organization, inspire developments in biomaterials, and contribute to polymer science.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"40 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145007132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanically Robust Polyvalerolactone Thermosets with Dual Recyclability","authors":"Hongyi Gu, Hao Ju, Kun Chen, Chang Sun, Lin Li, Jiayao Chen, Zhen Zhang, Peng-Fei Cao","doi":"10.1021/acs.macromol.5c00904","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c00904","url":null,"abstract":"While the incorporation of dynamic covalent bonds (DCBs) in thermosets is widely employed, the materials inevitably downgrade substantially during repetitive physical recycling. Meanwhile, chemical recycling of polymers back to starting monomers often requires significant energy/resource input during the (de/re)polymerization process. To address such a dilemma, we propose a dual-recycling strategy that integrates the advantages of DCBs and chemical recycling by cross-linking chemically recyclable polyesters with DCB-containing cross-linkers. A series of poly(valerolactone) (PVL)-based covalent adaptable networks (CANs) were constructed featuring a functionalized PVL backbone and dynamic boronic-ester-containing cross-linkers to enable simultaneous physical and chemical recyclability. Through fine-tuning the balance between crystallinity and cross-linking density, the CANs exhibited outstanding mechanical properties, including a tensile strength up to 17.7 MPa and an elongation at a break of 1164%. Owing to the dynamic exchange characteristic of boronic esters, the CANs retained nearly identical performance to the original samples after five cycles of physical recycling. Furthermore, the CANs could undergo catalytically assisted chemical recycling with Sn(Oct)₂, allowing the recovery of starting monomer. This work provided a valuable approach for the development of dual-recyclable high-performance polymer networks as a potential solution to the current challenges in thermosets recycling.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"68 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145007172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}