Macromolecules最新文献_第3页

Impact of the Exposure Plane on the Homoepitaxy of Poly(L-lactic acid)

IF 5.5 1区化学

Macromolecules Pub Date : 2025-03-28 DOI: 10.1021/acs.macromol.5c00180

Yunpeng Li, Meilin Ma, Binghui Xu, Rui Xin, Shouke Yan

{"title":"Impact of the Exposure Plane on the Homoepitaxy of Poly(L-lactic acid)","authors":"Yunpeng Li, Meilin Ma, Binghui Xu, Rui Xin, Shouke Yan","doi":"10.1021/acs.macromol.5c00180","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c00180","url":null,"abstract":"It is confirmed that cold crystallization of PLLA on melt-drawn polyethylene (PE) produces a majority of lamellae with long axes aligned along the PE chain direction and a minority of lamellae inclined by 64° to the major ones. These inclined PLLA lamellae are correlated to the homoepitaxy of PLLA on the early-formed major lamellae. There is, however, no experimental evidence for it. In this work, the homoepitaxy of PLLA with different optical purities on its single polymer substrates with varied orientations has been studied. Intriguing results have been found, which shed more light on the homoepitaxy of PLLA. First, the homoepitaxy of amorphous PLLA on different PLLA substrates takes place constantly regardless of optical purity and orientation status of the used substrates, leading to the formation of an ordered structure. The ordered structure is, at all events, optical purity- and substrate orientation status-dependent. It has been discovered that the homoepitaxy of PLLA with an optical purity of 95% (PLLA-95) on the uniaxially oriented PLLA-95 melt-drawn films generates an ordered lamellar structure, consistent with the used substrates in all cases. On the other hand, the homoepitaxy of PLLA-95 on PE-induced PLLA-95 oriented films with the (100) exposure plane produces abundant lamellae inclined by 64° to the lamellae in the substrate. Moreover, the homoepitaxy of PLLA with 89% optical purity (PLLA-89) cannot result in the formation of inclined lamellae on the PE-induced PLLA-89 substrate at all, while PLLA-95 can be less pronounced. This demonstrates the important role of optical purity of PLLAs for both the epitaxial layer and the substrate film in its homoepitaxy behavior.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"23 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143734480","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}

引用次数: 0

Correction to “Time-Salt Type Superposition and Salt Processing of Poly(methacrylamide) Hydrogel based on Hofmeister Series”

IF 5.5 1区化学

Macromolecules Pub Date : 2025-03-27 DOI: 10.1021/acs.macromol.5c00690

Yijie Jin, Shan Lu, Xinran Chen, Qianyao Fang, Xin Guan, Liguo Qin, Chongyi Chen, Chuanzhuang Zhao

引用次数: 0

Polymer and Site Diffusion of PSS during PSS/PDADMA Multilayer Buildup

IF 5.5 1区化学

Macromolecules Pub Date : 2025-03-27 DOI: 10.1021/acs.macromol.4c03209

Annekatrin Sill, Per-Ole Hilken, Christiane A. Helm

引用次数: 0

Synthesis of Bifunctional Copolyesters via Chemoselective Ring-Opening Copolymerization of δ-Lactone Derived from CO2 and Butadiene with ε-Caprolactone

IF 5.5 1区化学

Macromolecules Pub Date : 2025-03-27 DOI: 10.1021/acs.macromol.5c00076

Junhao Shen, Jinbo Zhang, Wenhui Kong, Yuanchi Ma, Shaofeng Liu, Zhibo Li

{"title":"Synthesis of Bifunctional Copolyesters via Chemoselective Ring-Opening Copolymerization of δ-Lactone Derived from CO2 and Butadiene with ε-Caprolactone","authors":"Junhao Shen, Jinbo Zhang, Wenhui Kong, Yuanchi Ma, Shaofeng Liu, Zhibo Li","doi":"10.1021/acs.macromol.5c00076","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c00076","url":null,"abstract":"3-Ethylidene-6-vinyltetrahydro-2H-pyran-2-one (EVP), derived from the telomerization of carbon dioxide (CO2) with 1,3-butadiene, emerges as a promising intermediate for the production of high-value added materials from CO2. However, the current impediment lies in the challenge of accessing selective ring-opening (co)polymerization of EVP because of unfavorable thermodynamics under mild conditions and the competitive polymerization of highly reactive C═C double bonds. In this study, we report the chemoselective ring-opening copolymerization of EVP (selective ring-opening rather than vinyl polymerization) with ε-caprolactone (CL), even at room temperature, by using a phosphazene/urea binary catalyst. This process exclusively yields the ring-opening product of copolyester poly(CL-co-EVP). The resultant poly(CL-co-EVP)s exhibit predictable molar masses (Mns), narrow distributions (D̵ < 1.2 for most cases), wide range of EVP-contents (0–60 mol %), and thus tunable thermal properties. The kinetic and reactivity ratio (rCL = 3.67 and rEVP = 0.17) studies indicate a gradient structure for poly(CL-co-EVP). Moreover, these poly(CL-co-EVP)s possess two distinct pendant alkene groups, an internal one and a terminal one, which are ready to undergo sequential functionalization to prepare bifunctional polyesters or form cross-linked polyesters. Poly(CL-co-EVP) copolyester with only a 2 mol % EVP incorporation shows a significant improvement in both tensile strength (σb) and elongation at break (εb) in comparison to PCL homopolymer with a similar Mn, while cross-linking further facilitates the transformation of PCL from thermoplastics to elastomers. This study opens avenues to utilize EVP and synthesize sustainable and functional polyesters.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"33 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143723613","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}

引用次数: 0

Size Effect of Form I Nanocrystals in Heterogeneous Nucleation of Polybutene-1

IF 5.5 1区化学

Macromolecules Pub Date : 2025-03-27 DOI: 10.1021/acs.macromol.4c02704

Yaguang Lu, Binghua Wang, Changyu Shen, Jingbo Chen, Bin Zhang

{"title":"Size Effect of Form I Nanocrystals in Heterogeneous Nucleation of Polybutene-1","authors":"Yaguang Lu, Binghua Wang, Changyu Shen, Jingbo Chen, Bin Zhang","doi":"10.1021/acs.macromol.4c02704","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c02704","url":null,"abstract":"The effect of Form I nanocrystal size on the induction time (ti) of isotactic polybutene-1 (iPB-1) heterogeneous nucleation has been investigated using small-/wide-angle X-ray scattering (SAXS/WAXS). By controlling the crystallization temperature (Tc1) of starting Form II and the transition time from Form II to Form I, respectively, we tune the height (h) and radius (r) of cylindrical Form I nanocrystals. A faster rate (i.e., a shorter ti) of heterogeneous nucleation on the larger nanocrystals (h ∼ 57 nm, r ∼ 23 nm) can be observed at the same mass fraction, even if the number density (N) of the smaller nanocrystals (h ∼ 37 nm, r ∼ 13 nm) is approximately five times that of the larger ones. In addition, we observed a dramatic increase (nearly 600%) in (1/ti)/N, representing the nucleation ability of individual nanocrystal, when h increases from ∼37 to ∼57 nm (by ∼54%) at a constant r of ∼15 nm, whereas (1/ti)/N only exhibits a ∼110% increase when the nanocrystal increases its radius by ∼120% at a constant h (e.g., ∼37 nm). These results indicate that h, rather than r, plays a central role in heterogeneous nucleation. Further, in a size range of h = 27–57 nm, we found the ti scales with h according to a power law ti ∼ h–α, where the exponent α increases with secondary crystallization temperature (Tc2). This reveals that the impact of h on the heterogeneous nucleation rate intensifies as the critical nucleus size increases. Our findings demonstrate that such an experimental model system could shed light on investigating the size effect of polymer nanocrystals in heterogeneous nucleation.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"36 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143723611","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}

引用次数: 0

Model-Guided and Scalable Approach to Synthesize Snowman Polymer Particles

IF 5.5 1区化学

Macromolecules Pub Date : 2025-03-27 DOI: 10.1021/acs.macromol.4c02922

Sara Beldarrain, Shaghayegh Hamzehlou, Jose Ramon Leiza, Edurne González

{"title":"Model-Guided and Scalable Approach to Synthesize Snowman Polymer Particles","authors":"Sara Beldarrain, Shaghayegh Hamzehlou, Jose Ramon Leiza, Edurne González","doi":"10.1021/acs.macromol.4c02922","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c02922","url":null,"abstract":"Some specific high-performance latex applications require nonequilibrium anisotropic particle morphologies, as they exhibit distinct properties compared to isotropic particles. In this work, snowman particles (a type of an anisotropic morphology) are sought. Even though several strategies have been reported in the literature to create these kinds of particles, the methods used are still limited by the particle size obtained and the small production scale. In the present work, a scalable two-step semibatch emulsion polymerization process is proposed to obtain snowman particles with sizes below 500 nm and localized functionalization in the core of the particles (head of the snowman particle). Cross-linked, functionalized, and soft (Tg: 40 °C) polymer latexes of different sizes have been synthesized as the first-stage polymer, using methyl methacrylate (MMA) and n-butyl acrylate (BA) as main monomers, acrylic acid (AA) and acrylamide (AM) as functional monomers, and allyl methacrylate (AMA) as a cross-linker. For the second-stage polymerization, a styrene (S)/BA monomer system has been used. Using a mathematical model, the necessary conditions for achieving particles with a snowman morphology are determined. It has been shown that the obtained morphology is strongly dependent on the V2/A1 parameter, which represents the ratio of the volume of the second-stage polymer to the surface area of the first-stage polymer. Model-guided experiments have been carried out in a wide range of V2/A1 ratios, successfully obtaining snowman particles of different sizes.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"183 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143723612","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}

引用次数: 0

Molecular Dynamics Simulation of Polymer Electrolyte Membrane for Understanding Structure and Proton Conductivity at Various Hydration Levels Using Neural Network Potential

IF 5.5 1区化学

Macromolecules Pub Date : 2025-03-26 DOI: 10.1021/acs.macromol.4c02607

Attila Taborosi, Kentaro Aoki, Nobuyuki Zettsu, Michihisa Koyama, Yuki Nagao

{"title":"Molecular Dynamics Simulation of Polymer Electrolyte Membrane for Understanding Structure and Proton Conductivity at Various Hydration Levels Using Neural Network Potential","authors":"Attila Taborosi, Kentaro Aoki, Nobuyuki Zettsu, Michihisa Koyama, Yuki Nagao","doi":"10.1021/acs.macromol.4c02607","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c02607","url":null,"abstract":"Alkyl sulfonated polyimides (ASPIs), as alternative polymer electrolytes for fuel cells, are known to exhibit lyotropic liquid crystalline behavior upon water uptake, forming organized lamellar structures and achieving high proton conductivity. Previous experimental studies have shown that ASPIs with planar backbones exhibit enhanced proton conductivity (0.2 S/cm) compared to those with bent backbones (0.03 S/cm). To explain this difference at the atomistic level, molecular dynamics simulations were conducted using a universal neural network potential. The appearance of monomer unit length in planar ASPIs, indicating higher molecular order, was found to correlate with higher proton conductivity compared to that of bent ASPIs. Despite the similar deprotonation and solvation of sulfonic acid groups in both planar and bent ASPIs, the proton conductivity was independent of these factors. Directional mean square displacement analysis provided further insights into the differences in proton conductivity between planar and bent types.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"3 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143703673","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}

引用次数: 0

Timed Formation and Aging of Complex Coacervates Using a Volatile Salt

IF 5.5 1区化学

Macromolecules Pub Date : 2025-03-26 DOI: 10.1021/acs.macromol.4c02728

Lunan Yan, Weiwei Zheng, Enola Muller, Philippe Carl, Thomas M. Hermans, Guillermo Monreal Santiago

{"title":"Timed Formation and Aging of Complex Coacervates Using a Volatile Salt","authors":"Lunan Yan, Weiwei Zheng, Enola Muller, Philippe Carl, Thomas M. Hermans, Guillermo Monreal Santiago","doi":"10.1021/acs.macromol.4c02728","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c02728","url":null,"abstract":"Biomolecular condensates are liquid droplets formed by liquid–liquid phase separation and play a role in a variety of cellular processes. In the past decade, there has been a growing interest in their study, often through the use of complex coacervates as models. Despite their similar properties, a limitation of complex coacervates is their inability to show time-dependent behavior, such as aging, as they are typically structures in thermodynamic equilibrium (or kinetically trapped). Here, we present a simple protocol to trigger the delayed formation and aging of coacervates. We use ammonium carbonate for this protocol, a volatile salt that decreases the ionic strength of the solution as it decomposes. Using this salt, we were able to program coacervate formation after delays ranging from hours to days. This process can be repeated multiple times, as the decomposition of ammonium carbonate leaves no waste products. The mechanical properties of the coacervate phase also change over time with this protocol, showing a steady increase in viscosity reminiscent of aging in condensates. Since the element that causes temporal evolution is the salt and not the coacervates, this protocol does not require any synthesis and can be easily adapted to multiple complex coacervates.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"125 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143703641","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}

引用次数: 0

New Method of Quickly Mapping Phase Diagrams of Polymer Solutions over a Wide Concentration Range

IF 5.5 1区化学

Macromolecules Pub Date : 2025-03-25 DOI: 10.1021/acs.macromol.4c03223

Xiangjun Gong, Lin Lian, Xianyu Qi, Jiahui Zhang, Wenjie Du, Juan Li, Jinliang Qiao, Chi Wu

引用次数: 0

Triple Effects of Fe3+ for the Integration of Mechanical Robustness, Reprocessability, and Unprecedented Thermal Stability into Polydimethylsiloxane

IF 5.5 1区化学

Macromolecules Pub Date : 2025-03-25 DOI: 10.1021/acs.macromol.4c02931

Ronghao Li, Junping Zheng

{"title":"Triple Effects of Fe3+ for the Integration of Mechanical Robustness, Reprocessability, and Unprecedented Thermal Stability into Polydimethylsiloxane","authors":"Ronghao Li, Junping Zheng","doi":"10.1021/acs.macromol.4c02931","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c02931","url":null,"abstract":"Despite the solution of the recycling difficulty of traditional thermosetting polymers including polydimethylsiloxane (PDMS) with the development of vitrimers, addressing the trade-off among the mechanical, reprocessing, and thermal properties of PDMS remains a scientific challenge. Herein, a novel “one-stone-for-three-birds” structural design strategy based on the triple effects of Fe3+ including coordination cross-linking for reinforcement and toughening, catalytic effect on silyl ether exchange for reprocessing, and free radical quenching for thermal stabilization is reported, realizing the integration of mechanical robustness, reprocessability, and unprecedentedly high thermal stability in PDMS for the first time. The PDMS vitrimer in this work exhibits the highest thermal stability among the reported PDMS vitrimers, comparable to commercial PDMS. To elucidate the intrinsic mechanisms of the triple effects of Fe3+ in PDMS, multiple characterizations have been performed from the microscopic structure to the macroscopic mechanical, reprocessing, and thermal performances both theoretically and experimentally.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"57 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143703642","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}

引用次数: 0