Macromolecules最新文献

{"title":"Selective Tuning of Benzothiadiazole Functionality Enables High Crystallinity and Mobility in Regiorandom n-Type Polymers for Organic Field-Effect Transistors","authors":"Panagiota Kafourou, Qiao He, Xiantao Hu, Mohamad Insan Nugraha, Wen Liang Tan, Joel Luke, Bowen Ding, Christopher R. McNeill, Thomas D. Anthopoulos, Martin Heeney","doi":"10.1021/acs.macromol.4c02854","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c02854","url":null,"abstract":"We report three novel donor–acceptor (D–A) copolymers sharing a common fused donor unit (CDTT) but differing in the functionalization of the benzothiadiazole (BT) acceptor unit. Acceptors bearing two cyano groups (DCNBT) are compared to novel acceptors bearing one cyano and one fluorine group (FCNBT) or one nitro and one fluoro group (NO₂FBT). The choice of the acceptor has a significant effect on the optoelectronic properties of the resulting polymers. In organic field-effect transistor (OFET) devices, PCDTT-DCNBT exhibited moderate performance with an electron mobility of 0.031 cm² V^–1 s^–1, whereas PCDTT-FCNBT demonstrated significantly improved electron mobility (0.4 cm² V^–1 s^–1). The improved performance is attributed to increased backbone linearity combined with a more coplanar backbone and high thin-film crystallinity. In comparison, the presence of the nitro group is shown to have a detrimental impact, with a blue-shifted absorption and a 0.2 eV increase in band gap compared to the cyanated polymers. Steric effects are shown to limit the nitro group’s π-accepting capability and result in reduced device performance, with an electron mobility of 0.024 cm² V^–1 s^–1. This study introduces a new BT building block and highlights that substituent tuning via cyano and fluorine groups is an effective approach for modulating polymer morphology and electron transport.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"51 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143666438","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":"Stress-Free Two-Way Liquid Crystalline–Semicrystalline Shape Memory Copolymer Actuators with Multistimuli-Responsive Actuation Behaviors","authors":"Yahui Wang, Shufen Ye, Shasha Li, Yanqing Li, Rong Yang","doi":"10.1021/acs.macromol.4c02171","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c02171","url":null,"abstract":"Stress-free two-way shape memory semicrystalline networks have garnered significant interest due to their ability to undergo reversible shape changes under external stimuli without repeated programming. However, their reversible actuation strain is often limited by the low anisotropy of the skeleton phase and the low crystallization rate and crystallinity of the actuation phase. In this study, we present a novel approach to developing two-way shape memory actuators utilizing liquid crystalline polymers as the skeleton phase, achieving high actuation strain and multistimuli-responsive behaviors. Specifically, we have designed and synthesized multiblock liquid crystalline–semicrystalline copolymers, poly(4,4’-bis(6-hydroxyhexyloxy)biphenyl phenylsuccinate)-poly(ethylene glycol) (PBDPS-PEG), and characterized their reversible shape changes in response to various external stimuli. The PBDPS block, easily stretchable within the liquid crystal phase, induces the epitaxial crystallization of the PEG block, forming microphase-separated ordered lamellar structures that facilitate reversible shape changes and anisotropic swelling behaviors under thermal, water absorption, and humidity stimuli. PBDPS-PEG actuators extend their functionality to grippers capable of manipulating objects across diverse environmental conditions and serve as humidity sensors, reflecting ambient humidity levels through reversible shape changes. This study highlights the potential of liquid crystalline–semicrystalline copolymer actuators in applications such as soft robotics, biomedical devices, and environmental sensors.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"46 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143666395","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":"Solid-State Processing of In Situ Blended Prepolymer with Z–N Synthesized UHMWPE: Role of the Prepolymer","authors":"Ravindra P. Gote, Jiayi Zhao, Dario Romano, Sanjay Rastogi","doi":"10.1021/acs.macromol.4c03097","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c03097","url":null,"abstract":"Ultrahigh molecular weight polyethylene (UHMWPE) synthesized using single-site catalytic systems, adopting a homogeneous bis(phenoxy-imine) Ti catalyst or half-metallocene Cr catalyst, under controlled polymerization conditions exhibits a unique low-entanglement state that enables solvent-free solid-state processing into strong, uniaxially and biaxially oriented films having unprecedented tensile strength and tensile modulus. The use of bis(phenoxy-imine) titanium catalysts supported on MgCl₂-based dual activator/support systems has been also shown to facilitate the heterogeneous synthesis of low-entangled UHMWPE, offering a promising industrial route. Conversely, commercially viable heterogeneous Ziegler–Natta catalysts yield UHMWPE with a high number of entanglements per chain (en-UHMWPE), necessitating solution spinning for fiber production. This study aims to investigate an industrially viable, solvent-free processing route for en-UHMWPE using commercial Ziegler–Natta catalysts. Herein, we synthesize UHMWPE sample via a one-pot, two-step protocol, incorporating a relatively low molar mass component (prepolymer) into the UHMWPE matrix, thus achieving a molecular blend between low and ultrahigh molar mass polymers. The sample exhibits excellent solid-state processability, achieving a remarkable draw ratio of up to 148× in a narrow temperature window. This resulted in outstanding mechanical properties of 1.6 and 127 N/tex of tensile strength and tensile modulus, respectively, for a Z–N synthesized polymer. Wide-angle X-ray diffraction (WAXD) measurements demonstrate a strong correlation between the draw ratio and the chain orientation, indicating a high degree of molecular alignment at higher draw ratios. In the drawn samples, solid-state nuclear magnetic resonance spectroscopy reveals the presence of a highly mobile amorphous fraction in the prepol/en-UHMWPE blend. The presence of the mobile fraction, arising from the melt-crystallized component in the drawn samples, is further supported by differential scanning calorimetry, WAXD, and small-angle X-ray scattering. On comparing with the low-entangled/disentangled samples synthesized using the single-site catalytic systems, the studies demonstrate that in the Z–N samples investigated here, the low molar mass component acts as an effective consolidant facilitating solid-state processing in a relatively narrow temperature window. The study emphasizes the influence of polymerization conditions and molecular characteristics in pursuing fundamental studies, especially on ultrahigh molar mass polymers.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"56 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143660653","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":"Fluorine-Free Sulfonated Poly(sulfone triazole)s with a Pendant Phosphaphenanthrene Moiety for Proton Exchange Membrane Applications","authors":"Bholanath Ghanti, Susanta Banerjee","doi":"10.1021/acs.macromol.5c00277","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c00277","url":null,"abstract":"Fluorinated proton exchange membranes (PEMs), such as Nafion, are the current state-of-the-art polymers, but they pose environmental challenges, driving the need for more sustainable fluorine-free alternatives. In this work, a phosphaphenanthrene-based bisalkyne monomer, 6-(1,1-bis(4-(prop-2-yn-1-yloxy)phenyl)ethyl)dibenzo[<i>c</i>,<i>e</i>][1,2]oxaphosphinine 6-oxide (DPAK), has been prepared. Utilizing this monomer (DPAK), a set of sulfonated poly(sulfone triazole)s with a pendant phosphaphenanthrene unit in the hard (hydrophobic) and soft (hydrophilic) segments of the copolymer have been designed and synthesized by the “click” reaction with various degrees of sulfonation values. The chemical structures of the copolymers were confirmed by various spectroscopic (FTIR, NMR, and XPS) techniques. The salt-form sulfonated poly(sulfone triazole) (SODPSNa-XX) copolymers exhibited high solubility in polar aprotic solvents. The acid-form sulfonated poly(sulfone triazole) (SODPSH-XX) copolymers exhibited high thermal, mechanical, and viscoelastic properties. Despite the absence of fluorinated moieties, the SODPSH-XX membranes possess moderate water absorption properties and show high-dimensional stability. The morphological (AFM, FESEM, and HRTEM) investigations of the SODPSH-XX membranes indicate the formation of an interconnected and well-segregated phase morphology, which created interconnected ionic cluster-like channels for the agile proton migration process. The SODPSH-90 membrane demonstrates much higher proton conductivity at 80 and 90 °C (σ: 100 and 112 mS/cm) than the few earlier reported fluorine-free sulfonated PEMs with comparable IEC_w values. The SODPSH-XX copolymers exhibited high durability, mainly associated with bulky cyclic phosphaphenanthrene and sulfonyl units in the copolymer backbone. Also, the SODPSH-70 to -90 membranes demonstrated better oxidative stability in Fenton’s reagent at 80 °C.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"17 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143666396","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":"Benchmarking the Elastic Modulus of Conjugated Polymers with Nanoindentation","authors":"Sri Harish Kumar Paleti, Shuichi Haraguchi, Zhiqiang Cao, Mariavittoria Craighero, Joost Kimpel, Zijin Zeng, Przemyslaw Sowinski, Di Zhu, Judith Pons i Tarrés, Youngseok Kim, Qifan Li, Junda Huang, Alexei Kalaboukhov, Besira Mihiretie, Simone Fabiano, Xiaodan Gu, Christian Müller","doi":"10.1021/acs.macromol.4c03081","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c03081","url":null,"abstract":"The elastic modulus is a critical parameter for the design of conjugated polymers for wearable electronics and correlates with electrical and thermal transport. Yet, widely different values have been reported for the same material because of the influence of processing and measurement conditions, including the temperature, mode, direction, and time scale of deformation. Thus, results obtained via different methods are usually not considered to be comparable. Here, disparate techniques from nanoindentation to tensile testing of free-standing films or films on water, buckling analysis, dynamic mechanical thermal analysis, oscillatory shear rheometry, and atomic force microscopy are compared. Strikingly, elastic modulus values obtained for the same batch of regioregular poly(3-hexylthiophene) differ by a factor of less than four, which suggests that an approximate comparison is possible. Considering the small amount of material that is typically available, nanoindentation in combination with creep analysis is identified as a reliable method for probing the elastic modulus of films with widely different elastic moduli ranging from less than 0.1 GPa in the case of a polythiophene with oligoether side chains to several GPa for polymers without side chains. Since films can display anisotropic elastic modulus values, it is proposed that nanoindentation is complemented with an in-plane technique such as tensile testing to ensure a full characterization using different modes of deformation.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"10 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143660655","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":"Relaxation Dynamics of Poly(ethylene oxide)","authors":"Peter Lunkenheimer, Alois Loidl","doi":"10.1021/acs.macromol.5c00265","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c00265","url":null,"abstract":"Poly(ethylene oxide) is an important polymer with many applications, e.g., as solid-state electrolyte in batteries. Its relaxation dynamics, characterizing its molecular and submolecular motions, which is relevant for many of these applications, was investigated numerous times, mostly employing dielectric spectroscopy. However, the various dynamic processes revealed by these studies were interpreted in conflicting ways and even their nomenclature in literature is highly inconsistent. Here we present the results of a detailed investigation of this polymer employing dielectric spectroscopy covering a relatively broad frequency and temperature range. We clearly detect four intrinsic relaxation processes. The slowest one most likely represents a so-called normal mode, reflecting global motions of the polymer chains, an interpretation that was not considered in previous works. The second process can be unequivocally identified with the segmental α relaxation, which governs glassy freezing and the glass transition. The third, only rarely detected process corresponds to the Johari–Goldstein relaxation of poly(ethylene oxide), widely overlooked in previous studies. The fourth and fastest process is unrelated to the supercooled and glassy state of this polymer and probably due to local, intramolecular motions.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"26 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143660663","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":"Supramolecular Polymer Brushes Grafted via Atom Transfer Radical Polymerization from Surfaces Presenting Non-covalent, Host–Guest Complex-Based Initiators","authors":"Friederike K. Metze, Harm-Anton Klok","doi":"10.1021/acs.macromol.5c00058","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c00058","url":null,"abstract":"This paper describes the synthesis of supramolecular polymer brushes via surface-initiated polymerization from adamantane-functionalized initiators that are noncovalently bound to β-cyclodextrin- or cucurbit[7]uril-modified substrates. Surface-initiated atom transfer radical polymerization in aqueous media allowed the growth of various hydrophilic polymer brushes with film thicknesses of up to 40 nm from β-cyclodextrin functionalized surfaces. The adamantane moiety not only forms a host–guest complex with β-cyclodextrin, but also with cucurbit[7]uril, which provides opportunities to study the effect of the binding strength of these supramolecular motifs on the film thickness and grafting density of the resulting polymer brushes. Comparison of supramolecular polymer brushes grown from β-cyclodextrin and cucurbit[7]uril-based noncovalent initiators reveals differences in grafting density that are much smaller than expected based on the differences in the solution binding constant of the corresponding host–guest complexes. Both the β-cyclodextrin as well as the cucurbit[7]uril-anchored supramolecular brushes were remarkably robust toward detachment of the polymer grafts. These observations are attributed to the fact that the rates of formation and dissociation of the host–guest complexes are much faster as compared to diffusion of free, detached polymer chains through the polymer brush film. As a result, the surface-grafted polymer brush presents a steric barrier that prevents detachment of individual chains, and also allows surface-initiated polymerization from substrates to which initiators are bound via putatively weak β-cyclodextrin-based host–guest complexes.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"34 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143660662","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":"Structures and Segmental Dynamics in Single-Chain Polymer Nanoparticles-Based All-Polymer Nanocomposites","authors":"Peizhi Zhao, Zhiwei Yan, Yuling Liang, Rongchun Zhang","doi":"10.1021/acs.macromol.5c00570","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c00570","url":null,"abstract":"All-polymer nanocomposites are attracting dramatic attention due to their unique mechanical and viscoelastic properties. In this study, via multiscale solid-state nuclear magnetic resonance (NMR) methods, it is clearly revealed that a polystyrene (PS)-based single-chain polymer nanoparticle (SCNP) is in closer proximity with linear poly(vinyl methyl ether) (PVME) chains compared to linear PS chains, leading to dramatically different phase separation structures as demonstrated by ¹H spin diffusion NMR experiments. High-resolution solid-state ¹H NMR spectroscopy at ultrafast magic-angle-spinning (MAS) beyond 90 kHz directly reveals the subtle difference in proximity as well as the hydrogen bonding interactions between PVME and PS (or PS-SCNP) at a molecular level. Due to closer proximity between the PS-SCNP and PVME, the segmental dynamics of PVME is also slowed down by its hydrogen bonding interactions with PS-SCNP as revealed by variable-contact-time cross-polarization (CP) experiments. Particularly, ¹H fast field cycling NMR experiments at variable temperatures clearly reveal the enhanced glassy and Rouse dynamic heterogeneity of PVME in the PS-SCNP/PVME blend. To the best of our knowledge, this is the first study to apply solid-state NMR spectroscopy to reveal the sophisticated interplay of structures and segmental dynamics in all-polymer nanocomposites at a molecular level, obtaining consistent results with molecular simulations, which could be helpful for the fundamental understanding of the unusual viscoelastic behaviors of all-polymer nanocomposites.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"9 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143660664","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":"Comparative Investigation on the Crystallization Behavior of Polypropylene Nucleated by Sorbitol-Based Nucleating Agents with and without Fibrous Network Formation","authors":"Xuan Sha, Junjin Duan, Jiachun Feng","doi":"10.1021/acs.macromol.4c03187","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c03187","url":null,"abstract":"Sorbitol derivatives are effective nucleating agents (NAs) for polypropylene (PP), and their nucleation capacity is generally accepted to associate with fibrous network formation before PP crystallization. However, whether the network must be preformed to promote PP crystallization is overlooked. To address this issue, this work adjusted the network to not form before PP crystallization and compared its effect on PP crystallization to NAs with the networks. Specifically, for PP containing 0.4 wt % Millad NX8000, a sorbitol-based NA, the network is controlled to form by cooling at 2 °C/min and not form by ice-water quenching. Both samples were heated to a temperature sufficient to erase the thermal history of PP while retaining the network of NAs present and absent (NA-p and NA-a), and subsequent PP crystallization was evaluated. Compared to PP/0.4NA-p, the slightly higher nucleation efficiency and density for PP/0.4NA-a indicate that the NA without networks exhibits comparable or even more effective nucleating effects. Additionally, NA-p restricts PP growth in the later crystallization stage and promotes the oriented growth after shear, whereas these phenomena weaken in PP/0.4NA-a. These findings provide new insights into the role of fibrous network formation in the effectiveness of sorbitol-based NAs.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"29 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143660661","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":"Molecular Simulation of Effects of Network Structure on Fracture Behavior of Gels Synthesized by Radical Polymerization","authors":"Tsutomu Furuya, Tsuyoshi Koga","doi":"10.1021/acs.macromol.4c02875","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c02875","url":null,"abstract":"The synthesis of high-strength gels with many entanglements by radical polymerization with high monomer and low cross-linker concentrations has recently been reported by several groups. In order to elucidate the toughening mechanism of such high-strength gels, the fracture behavior of gels synthesized by radical polymerization is studied by a coarse-grained molecular dynamics simulation. The simulation results qualitatively reproduce the reported experimental results; the gels formed with high monomer and low cross-linker concentrations have a small number of elastically effective chains due to cross-linking, but many polymer entanglements, and exhibit high toughness without sacrificing the shear modulus. In the tough gels, the structural changes that suppress the orientation of the polymer chains in the elongation direction and stress concentration are confirmed. Analysis of the relationship between network structure and fracture behavior reveals that the chain length between cross-linking points and the number of entanglements are important for the toughness of the gels.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"92 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143660656","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}