Macromolecules最新文献_第10页

Tuning Copolymer Microstructure Using Ring-Opening Cross-Metathesis Polymerization 用开环交叉复分解聚合调整共聚物微观结构

IF 5.1 1区化学

Macromolecules Pub Date : 2025-05-05 DOI: 10.1021/acs.macromol.5c0065910.1021/acs.macromol.5c00659

Jeffrey C. Foster*, and , Isaiah T. Dishner,

{"title":"Tuning Copolymer Microstructure Using Ring-Opening Cross-Metathesis Polymerization","authors":"Jeffrey C. Foster*,  and , Isaiah T. Dishner, ","doi":"10.1021/acs.macromol.5c0065910.1021/acs.macromol.5c00659","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c00659https://doi.org/10.1021/acs.macromol.5c00659","url":null,"abstract":"The capability of ring-opening cross-metathesis (RO/CM) polymerization to produce alternating copolymers was studied. By treating commercial polybutadiene (PB) with bulky oxanorbornene monomers and Ru-based olefin metathesis catalysts, alternating copolymers were produced under mild conditions with high sequence fidelities. We found that alternating copolymers could be produced starting from a variety of butadiene sources including PB, cyclooctadiene (COD), or t,t,t-1,5,9-cyclododecatriene (CDT), highlighting for the first time the kinetic pathway independence of this process. Kinetic copolymerization analysis of an oxanorbonene monomer with CDT revealed that much higher monomer conversions were obtained compared with the analogous homopolymerizations and showed evidence of alternating monomer incorporation. Copolymerization of these monomers also enabled good control when targeting different molecular weights. Copolymer thermal analysis revealed a strong correlation between thermal behavior and alternating sequence fidelity, providing a second lever beyond composition to tune thermal behavior. These data demonstrate that a broad variety of polymer microstructures can be accessed via RO/CM polymerization and highlight the potential of CDT in alternating copolymer synthesis.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"58 10","pages":"5170–5176 5170–5176"},"PeriodicalIF":5.1,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144137638","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

Synthesis and Morphological Analysis of Well-Defined Poly(2,6-dimethyl-1,4-phenylene ether)-b-Poly(dimethylsiloxane) 定义良好的聚（2,6-二甲基-1,4-苯基醚）-b-聚二甲基硅氧烷的合成及形态分析

IF 5.1 1区化学

Macromolecules Pub Date : 2025-05-05 DOI: 10.1021/acs.macromol.5c0073010.1021/acs.macromol.5c00730

Riku Takahashi, Kan Hatakeyama-Sato, Yuta Nabae and Teruaki Hayakawa*,

{"title":"Synthesis and Morphological Analysis of Well-Defined Poly(2,6-dimethyl-1,4-phenylene ether)-b-Poly(dimethylsiloxane)","authors":"Riku Takahashi, Kan Hatakeyama-Sato, Yuta Nabae and Teruaki Hayakawa*, ","doi":"10.1021/acs.macromol.5c0073010.1021/acs.macromol.5c00730","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c00730https://doi.org/10.1021/acs.macromol.5c00730","url":null,"abstract":"Microphase-separated structures of block copolymers have been leveraged in advanced functional materials. However, such unique morphologies have not been extensively studied for block copolymers comprising poly(2,6-dimethyl-1,4-phenylene ether) (PPE), although PPE is a commonly utilized engineering plastic. Herein, based on precisely prepared PPE, we have developed PPE-containing block copolymers, exhibiting various microphase-separated structures such as spheres, lamellae, and cylinders. As the second block component, poly(dimethylsiloxane) (PDMS) was synthesized via living ring-opening polymerization. Block copolymers (PPE-b-PDMS) with different compositions were efficiently obtained by employing hydrosilylation using Karstedt’s catalyst. Additionally, it was found that PPE-b-PDMS followed different pathways of microphase-separated structure formation depending on the solvent used for sample preparation. The developed morphologies are expected to enhance the properties of PPE through the combination with other block components and the control of nanometer-scale internal structures.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"58 10","pages":"5271–5282 5271–5282"},"PeriodicalIF":5.1,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acs.macromol.5c00730","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144137587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Single-Fiber Visualization of Poly(ethylene terephthalate) during Alkaline Hydrolysis: Testing of Surface Reaction Model and Mechanism 碱性水解过程中聚对苯二甲酸乙酯单纤维的可视化：表面反应模型和机理的测试

IF 5.5 1区化学

Macromolecules Pub Date : 2025-05-04 DOI: 10.1021/acs.macromol.4c02602

Abigail K. Nason, Jingzhi Hu, Brady A. Bruno, Jin Suntivich

引用次数: 0

Single-Fiber Visualization of Poly(ethylene terephthalate) during Alkaline Hydrolysis: Testing of Surface Reaction Model and Mechanism 碱性水解过程中聚对苯二甲酸乙酯单纤维的可视化：表面反应模型和机理的测试

IF 5.1 1区化学

Macromolecules Pub Date : 2025-05-04 DOI: 10.1021/acs.macromol.4c0260210.1021/acs.macromol.4c02602

Abigail K. Nason, Jingzhi Hu, Brady A. Bruno and Jin Suntivich*,

引用次数: 0

Elucidation of the Termination Mechanism of the Radical Polymerization of Isoprene 异戊二烯自由基聚合终止机理的研究

IF 5.1 1区化学

Macromolecules Pub Date : 2025-05-02 DOI: 10.1021/acs.macromol.5c0070510.1021/acs.macromol.5c00705

Naila Yamin, Masatoshi Tosaka and Shigeru Yamago*,

引用次数: 0

Paradox in Sintering of Nascent Ultrahigh Molecular Weight Polymers in the Solid State 新生超高分子量聚合物固态烧结中的悖论

IF 5.1 1区化学

Macromolecules Pub Date : 2025-05-02 DOI: 10.1021/acs.macromol.5c0073110.1021/acs.macromol.5c00731

Fuhai Zhou, Jiayi Zhao and Sanjay Rastogi*,

{"title":"Paradox in Sintering of Nascent Ultrahigh Molecular Weight Polymers in the Solid State","authors":"Fuhai Zhou, Jiayi Zhao and Sanjay Rastogi*, ","doi":"10.1021/acs.macromol.5c0073110.1021/acs.macromol.5c00731","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c00731https://doi.org/10.1021/acs.macromol.5c00731","url":null,"abstract":"The sintering of ceramics, metals, and polymers has been a subject of intense interest, especially when the materials can be sintered without melting in the solid state. In contrast to inorganic materials, crystallizable polymers have segments of the same chain residing in crystalline and noncrystalline regions. The topological constraints between the chain segments residing in the noncrystalline region are strongly influenced by the crystallization and/or polymerization history. Here, we address the influence of topological constraints on the deformation of crystalline domains to the extent that lattice diffusion and grain boundary diffusion in semicrystalline polymers can be achieved without melting. This allows ease in translation of the macroscopic forces to the molecular length scale in the sintered polymer, facilitating uniaxial and biaxial deformation below the melting temperature. Since solid-state processing circumvents the challenges of melt processing, entropic relaxation of the oriented chains, and thermal degradation of the polymers at high temperatures, unprecedented mechanical properties in the uniaxial and biaxial drawn intractable ultrahigh molar mass polymers have been achieved. Thus, solvent-free sustainable solutions are provided for the processing of the intractable engineering polymers needed for demanding applications. The ease of sintering allows the fabrication of grain-boundary-free products, with advantages in prostheses.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"58 9","pages":"4602–4614 4602–4614"},"PeriodicalIF":5.1,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143934382","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

Elucidation of the Termination Mechanism of the Radical Polymerization of Isoprene 异戊二烯自由基聚合终止机理的研究

IF 5.5 1区化学

Macromolecules Pub Date : 2025-05-02 DOI: 10.1021/acs.macromol.5c00705

Naila Yamin, Masatoshi Tosaka, Shigeru Yamago

引用次数: 0

Paradox in Sintering of Nascent Ultrahigh Molecular Weight Polymers in the Solid State 新生超高分子量聚合物固态烧结中的悖论

IF 5.5 1区化学

Macromolecules Pub Date : 2025-05-02 DOI: 10.1021/acs.macromol.5c00731

Fuhai Zhou, Jiayi Zhao, Sanjay Rastogi

{"title":"Paradox in Sintering of Nascent Ultrahigh Molecular Weight Polymers in the Solid State","authors":"Fuhai Zhou, Jiayi Zhao, Sanjay Rastogi","doi":"10.1021/acs.macromol.5c00731","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c00731","url":null,"abstract":"The sintering of ceramics, metals, and polymers has been a subject of intense interest, especially when the materials can be sintered without melting in the solid state. In contrast to inorganic materials, crystallizable polymers have segments of the same chain residing in crystalline and noncrystalline regions. The topological constraints between the chain segments residing in the noncrystalline region are strongly influenced by the crystallization and/or polymerization history. Here, we address the influence of topological constraints on the deformation of crystalline domains to the extent that lattice diffusion and grain boundary diffusion in semicrystalline polymers can be achieved without melting. This allows ease in translation of the macroscopic forces to the molecular length scale in the sintered polymer, facilitating uniaxial and biaxial deformation below the melting temperature. Since solid-state processing circumvents the challenges of melt processing, entropic relaxation of the oriented chains, and thermal degradation of the polymers at high temperatures, unprecedented mechanical properties in the uniaxial and biaxial drawn intractable ultrahigh molar mass polymers have been achieved. Thus, solvent-free sustainable solutions are provided for the processing of the intractable engineering polymers needed for demanding applications. The ease of sintering allows the fabrication of grain-boundary-free products, with advantages in prostheses.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"40 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143901144","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

Machine-Learning-Assisted Design of Mechanically Robust Room-Temperature Self-Healing Epoxy Resins 机械稳健性室温自愈环氧树脂的机器学习辅助设计

IF 5.5 1区化学

Macromolecules Pub Date : 2025-05-01 DOI: 10.1021/acs.macromol.5c00667

Haitao Wu, Hao Wang, Changcheng Wang, Zhaoyang Yuan, Hu Xu, Jing Zheng, Mengjin Jiang, Jinrong Wu

{"title":"Machine-Learning-Assisted Design of Mechanically Robust Room-Temperature Self-Healing Epoxy Resins","authors":"Haitao Wu, Hao Wang, Changcheng Wang, Zhaoyang Yuan, Hu Xu, Jing Zheng, Mengjin Jiang, Jinrong Wu","doi":"10.1021/acs.macromol.5c00667","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c00667","url":null,"abstract":"Epoxy resins are the most widely used thermosets, yet they typically lack the capability to self-heal at room temperature due to their molecular chains and networks being immobilized in a glassy state. Herein, machine learning identifies fractional free volume as a crucial factor for enabling self-healing in the glassy state. Guided by this insight, we designed an epoxy network incorporating dangling chains together with numerous hydrogen bonds and aromatic disulfide bonds. The dangling chains introduce large free volume, facilitating the reorganization of hydrogen bonds and the radical-mediated exchange of aromatic disulfide bonds, thereby imparting prominent self-healing capability at room temperature. Notably, the damaged epoxy not only can recover 81.2% of its tensile strength without intervention but also can autonomously and completely eliminate electrical tree damage and scratches at room temperature. Under mild compression, 100% healing occurs within tens of minutes in the glassy state. Additionally, the optimized epoxy exhibits high physicomechanical properties with a tensile strength of 42.1 MPa, a modulus of 2.9 GPa, and a glass transition temperature of 53.2 °C. Its ability to self-heal both electrical tree and mechanical damage at room temperature positions this epoxy as a promising material for advanced insulating and sealing applications.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"21 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143897779","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

Effect of the Second Network on First Network Rupture and the Origin of Energy Dissipation in Double Network Hydrogels 双网状水凝胶中第二网状对第一网状破裂的影响及能量耗散的来源

IF 5.5 1区化学

Macromolecules Pub Date : 2025-05-01 DOI: 10.1021/acs.macromol.5c00331

Zhi Jian Wang, Gumi Wei, Tasuku Nakajima, Jian Ping Gong

{"title":"Effect of the Second Network on First Network Rupture and the Origin of Energy Dissipation in Double Network Hydrogels","authors":"Zhi Jian Wang, Gumi Wei, Tasuku Nakajima, Jian Ping Gong","doi":"10.1021/acs.macromol.5c00331","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c00331","url":null,"abstract":"The detection of mechanoradicals generated by homolytic bond scission enables the quantitative determination of the polymer network rupture during deformation in hydrogels. In this study, we investigate, in double network (DN) hydrogels, how the stretchable second network affects the stress distribution and rupture of the first network and how it contributes to energy dissipation by correlating bond scission with mechanical hysteresis. By increasing the second network density while keeping the first network constant, the tensile behavior of DN gels transitions from typical DN characteristics, exhibiting yielding with necking and strain-hardening, to an oversupported state, showing yielding and strain-hardening without necking, accompanied by reduced bond scission in the first network. Notably, the first network bond scission occurs extensively beyond the yield point and saturates at large strains, irrespective of necking behavior. Furthermore, the energy dissipated per bond cleavage remains constant in the necking regime but increases significantly in the strain-hardening regime and rises with higher second network density, indicating dissipation in the second network through internetwork entanglements. These trends are consistent across DN gels with both weak and strong cross-linkers in the first network, with the weak cross-linker leading to greater bond scission. This study not only deepens the understanding of the molecular mechanism underlying DN materials but also assists in designing mechanoresponsive functional materials based on DN mechanochemistry.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"53 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143897777","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