Pub Date : 2025-06-11DOI: 10.1038/s41428-025-01055-3
Akihiko Toda
Linear polymers crystallize by the folding of chains on the nanometer scale. Owing to their metastable nature, folded-chain crystals (FCCs) exhibit unique phenomena during crystallization and melting. Understanding the melting kinetics of FCCs is challenging because of the complexity that results from the melting‒recrystallization‒remelting cycle and the reorganization occurring during heating. Fast-scanning calorimetry (FSC) has significantly advanced our understanding of melting kinetics. This review provides an overview of the research conducted on the melting kinetics of melt-grown crystals, focusing particularly on the following aspects: (1) the thermodynamics of folded-chain polymer crystals; (2) Gibbs‒Thomson and Hoffman‒Weeks plots, which are used to determine the equilibrium melting point; (3) the unique kinetic barrier of FCC melting, which is determined from the heating rate dependence of the superheated melting peak examined by calorimetry and from the morphological observation results of the isothermal melting behavior of single crystals in bulk samples; (4) the reconfirmation of results using a recently developed FSC with a chip sensor; (5) the exponential dependence of the melting rate on the degree of superheating, as determined from isothermal melting kinetics conducted using FSC; and (6) thermal Gibbs‒Thomson plots as an application of melting kinetics studies. An overview of the research on the melting kinetics of melt-grown folded-chain crystals (FCC) of polymers are provided, focusing particularly on the following aspects: (1) the thermodynamics; (2) Gibbs‒Thomson and Hoffman‒Weeks plots; (3) the unique kinetic barrier of FCC melting; (4) the results using a recently developed FSC with a chip sensor; (5) the exponential dependence of the melting rate on the degree of superheating, as determined from isothermal melting kinetics conducted using FSC; and (6) thermal Gibbs‒Thomson plots as an application of melting kinetics studies.
{"title":"Melting kinetics of polymer crystals","authors":"Akihiko Toda","doi":"10.1038/s41428-025-01055-3","DOIUrl":"10.1038/s41428-025-01055-3","url":null,"abstract":"Linear polymers crystallize by the folding of chains on the nanometer scale. Owing to their metastable nature, folded-chain crystals (FCCs) exhibit unique phenomena during crystallization and melting. Understanding the melting kinetics of FCCs is challenging because of the complexity that results from the melting‒recrystallization‒remelting cycle and the reorganization occurring during heating. Fast-scanning calorimetry (FSC) has significantly advanced our understanding of melting kinetics. This review provides an overview of the research conducted on the melting kinetics of melt-grown crystals, focusing particularly on the following aspects: (1) the thermodynamics of folded-chain polymer crystals; (2) Gibbs‒Thomson and Hoffman‒Weeks plots, which are used to determine the equilibrium melting point; (3) the unique kinetic barrier of FCC melting, which is determined from the heating rate dependence of the superheated melting peak examined by calorimetry and from the morphological observation results of the isothermal melting behavior of single crystals in bulk samples; (4) the reconfirmation of results using a recently developed FSC with a chip sensor; (5) the exponential dependence of the melting rate on the degree of superheating, as determined from isothermal melting kinetics conducted using FSC; and (6) thermal Gibbs‒Thomson plots as an application of melting kinetics studies. An overview of the research on the melting kinetics of melt-grown folded-chain crystals (FCC) of polymers are provided, focusing particularly on the following aspects: (1) the thermodynamics; (2) Gibbs‒Thomson and Hoffman‒Weeks plots; (3) the unique kinetic barrier of FCC melting; (4) the results using a recently developed FSC with a chip sensor; (5) the exponential dependence of the melting rate on the degree of superheating, as determined from isothermal melting kinetics conducted using FSC; and (6) thermal Gibbs‒Thomson plots as an application of melting kinetics studies.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 10","pages":"1049-1065"},"PeriodicalIF":2.7,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.comhttps://www.nature.com/articles/s41428-025-01055-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145228247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-06-11DOI: 10.1038/s41428-025-01065-1
Tarek Ibrahim, Sabita Rimal, Kiril Samiahulin, Nanzhi Zang, Hao Sun
Degradable polymers are promising materials for use to reduce plastic waste and advance biomedical applications. However, to meet the demands of specific applications, tailoring the properties of degradable polymers through precise modification of their chemical structures is critical. Herein, we present a new class of degradable and functionalizable polyacetals synthesized by the ring-opening metathesis copolymerization (ROMP) of two commercially available monomers: dimethyl oxanorbornadiene-2,3-dicarboxylate (OND) and 4,7-dihydro-1,3-dioxepin (DXP). The resulting polyacetals are not only acid-degradable but also readily and efficiently functionalizable via thia–Michael addition, yielding degradable polymer materials with various functional groups and tunable thermal properties. A new class of degradable and functionalizable polyacetals was designed through the ring-opening metathesis copolymerization of two commercially available monomers: dimethyl oxanorbornadiene-2,3-dicarboxylate and 4,7-dihydro-1,3-dioxepin. The resulting polyacetals are not only acid-degradable but also efficiently functionalizable via thia–Michael addition, giving rise to degradable polymer materials with various functional groups and tunable thermal properties.
{"title":"Degradable and functionalizable polyacetals synthesized via ring-opening metathesis copolymerization","authors":"Tarek Ibrahim, Sabita Rimal, Kiril Samiahulin, Nanzhi Zang, Hao Sun","doi":"10.1038/s41428-025-01065-1","DOIUrl":"10.1038/s41428-025-01065-1","url":null,"abstract":"Degradable polymers are promising materials for use to reduce plastic waste and advance biomedical applications. However, to meet the demands of specific applications, tailoring the properties of degradable polymers through precise modification of their chemical structures is critical. Herein, we present a new class of degradable and functionalizable polyacetals synthesized by the ring-opening metathesis copolymerization (ROMP) of two commercially available monomers: dimethyl oxanorbornadiene-2,3-dicarboxylate (OND) and 4,7-dihydro-1,3-dioxepin (DXP). The resulting polyacetals are not only acid-degradable but also readily and efficiently functionalizable via thia–Michael addition, yielding degradable polymer materials with various functional groups and tunable thermal properties. A new class of degradable and functionalizable polyacetals was designed through the ring-opening metathesis copolymerization of two commercially available monomers: dimethyl oxanorbornadiene-2,3-dicarboxylate and 4,7-dihydro-1,3-dioxepin. The resulting polyacetals are not only acid-degradable but also efficiently functionalizable via thia–Michael addition, giving rise to degradable polymer materials with various functional groups and tunable thermal properties.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 11","pages":"1269-1273"},"PeriodicalIF":2.7,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.comhttps://www.nature.com/articles/s41428-025-01065-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145436537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-06-09DOI: 10.1038/s41428-025-01056-2
Hiroaki Nobuoka, Osamu Urakawa, Tadashi Inoue
Stress softening, known as the Mullins effect, has a significant effect on the durability and performance of filler-reinforced rubber, making it a critical issue in designing products for practical applications. While empirical equations are widely used, they fail to capture the intricate and nonlinear behaviors that are characteristic of filler-reinforced rubber. To address this limitation, this study developed a simplified equation to predict the Mullins effect. The model is based on the assumption that the Mullins effect originates from the destruction of particle aggregation structures, and the relationship between the degree of destruction and the stretch ratio is expressed using extreme value statistics. Validation against experimental data revealed that the equation accurately predicts the behavior of rubber reinforced with carbon black (CB) or silica. Additionally, in systems with CB-filled rubber, the equation demonstrated good agreement with the experimental results, even when the CB content was varied. These findings suggest that the proposed model is versatile and effective for predicting the Mullins effect under different conditions, providing a useful tool for understanding and optimizing the performance of filler-reinforced rubber in practical applications. Stress softening, or the Mullins effect, critically affects the performance of filler-reinforced rubber. This study proposes a simplified model based on the destruction of particle aggregates, using extreme value statistics to relate damage to stretch ratio. The model accurately predicts behaviors of rubber filled with carbon black or silica, showing good agreement with experiments across varying filler contents. It offers a practical tool for designing durable rubber materials.
{"title":"A heuristic study of the Mullins effect in reinforced rubber by using the Weibull distribution","authors":"Hiroaki Nobuoka, Osamu Urakawa, Tadashi Inoue","doi":"10.1038/s41428-025-01056-2","DOIUrl":"10.1038/s41428-025-01056-2","url":null,"abstract":"Stress softening, known as the Mullins effect, has a significant effect on the durability and performance of filler-reinforced rubber, making it a critical issue in designing products for practical applications. While empirical equations are widely used, they fail to capture the intricate and nonlinear behaviors that are characteristic of filler-reinforced rubber. To address this limitation, this study developed a simplified equation to predict the Mullins effect. The model is based on the assumption that the Mullins effect originates from the destruction of particle aggregation structures, and the relationship between the degree of destruction and the stretch ratio is expressed using extreme value statistics. Validation against experimental data revealed that the equation accurately predicts the behavior of rubber reinforced with carbon black (CB) or silica. Additionally, in systems with CB-filled rubber, the equation demonstrated good agreement with the experimental results, even when the CB content was varied. These findings suggest that the proposed model is versatile and effective for predicting the Mullins effect under different conditions, providing a useful tool for understanding and optimizing the performance of filler-reinforced rubber in practical applications. Stress softening, or the Mullins effect, critically affects the performance of filler-reinforced rubber. This study proposes a simplified model based on the destruction of particle aggregates, using extreme value statistics to relate damage to stretch ratio. The model accurately predicts behaviors of rubber filled with carbon black or silica, showing good agreement with experiments across varying filler contents. It offers a practical tool for designing durable rubber materials.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 9","pages":"995-1002"},"PeriodicalIF":2.7,"publicationDate":"2025-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.comhttps://www.nature.com/articles/s41428-025-01056-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144990846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-06-05DOI: 10.1038/s41428-025-01027-7
Keiji Tanaka
{"title":"PJ ZEON Award for outstanding papers in Polymer Journal 2024","authors":"Keiji Tanaka","doi":"10.1038/s41428-025-01027-7","DOIUrl":"10.1038/s41428-025-01027-7","url":null,"abstract":"","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 6","pages":"601-603"},"PeriodicalIF":2.3,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-025-01027-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144214280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-06-03DOI: 10.1038/s41428-025-01062-4
Zhichao Jiang, Yi Ding, Zhibin Chen, Biao Zuo
Although a multilayered metallic coatings on epoxy surfaces can enhance material performance, under acidic and salty conditions, such as sweat, the coatings usually delaminate from polymer surfaces. Therefore, we investigated the interfacial failure of a Ni/Ag/Ni coating on an epoxy surface after long-term exposure to salt spray air or artificial sweat containing abundant Cl− ions. Cross-sectional atomic force microscopy and X-ray photoelectron spectroscopy were used to probe the changes in the interfacial morphologies and depth profiles of the chemical composition, respectively, to elucidate the mechanism by which Ni/Ag/Ni trilayered coatings delaminate from epoxy substrates in Cl−-containing atmospheres. The results revealed that Cl− ions penetrated through the epoxy, diffused into the metal–polymer interface, and dissolved the Ni layer at the epoxy surface, detaching the metallic layer from the polymer surface. In response to the failure mechanism mentioned above, we propose that by partially replacing the Ni primer layer with Ni2O3, which is inert in acidic Cl− atmospheres, the Ni2O3/Ni/Ag/Ni coating strongly resists corrosion in salt spray air and possesses good long-term interfacial bonding under acidic Cl− atmospheres. The mechanism of interfacial failure of Ni/Ag/Ni coating on epoxy surface after long-term treatment in air of artificial sweat were evaluated by cross-section AFM and XPS depth profiling. It was revealed that Cl ions penetrate the epoxy substrate, diffuse into metal-polymer interface and dissolve the primer Ni layer, resulting a delamination of metal coating from epoxy substrate. A Ni₂O₃ layer was introduced to construct the Ni₂O₃/Ni/Ag/Ni structure, which exhibits superior interfacial bonding performance in acidic Cl− atmosphere.
{"title":"Quantitative characterization of the interfacial failure of metallic coatings on epoxy substrates in salty atmospheres","authors":"Zhichao Jiang, Yi Ding, Zhibin Chen, Biao Zuo","doi":"10.1038/s41428-025-01062-4","DOIUrl":"10.1038/s41428-025-01062-4","url":null,"abstract":"Although a multilayered metallic coatings on epoxy surfaces can enhance material performance, under acidic and salty conditions, such as sweat, the coatings usually delaminate from polymer surfaces. Therefore, we investigated the interfacial failure of a Ni/Ag/Ni coating on an epoxy surface after long-term exposure to salt spray air or artificial sweat containing abundant Cl− ions. Cross-sectional atomic force microscopy and X-ray photoelectron spectroscopy were used to probe the changes in the interfacial morphologies and depth profiles of the chemical composition, respectively, to elucidate the mechanism by which Ni/Ag/Ni trilayered coatings delaminate from epoxy substrates in Cl−-containing atmospheres. The results revealed that Cl− ions penetrated through the epoxy, diffused into the metal–polymer interface, and dissolved the Ni layer at the epoxy surface, detaching the metallic layer from the polymer surface. In response to the failure mechanism mentioned above, we propose that by partially replacing the Ni primer layer with Ni2O3, which is inert in acidic Cl− atmospheres, the Ni2O3/Ni/Ag/Ni coating strongly resists corrosion in salt spray air and possesses good long-term interfacial bonding under acidic Cl− atmospheres. The mechanism of interfacial failure of Ni/Ag/Ni coating on epoxy surface after long-term treatment in air of artificial sweat were evaluated by cross-section AFM and XPS depth profiling. It was revealed that Cl ions penetrate the epoxy substrate, diffuse into metal-polymer interface and dissolve the primer Ni layer, resulting a delamination of metal coating from epoxy substrate. A Ni₂O₃ layer was introduced to construct the Ni₂O₃/Ni/Ag/Ni structure, which exhibits superior interfacial bonding performance in acidic Cl− atmosphere.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 9","pages":"1015-1023"},"PeriodicalIF":2.7,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.comhttps://www.nature.com/articles/s41428-025-01062-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144990845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-06-03DOI: 10.1038/s41428-025-01061-5
Daisuke Aoki, Kento Yasuda, Kotaro Uchiyama, Koji Arimitsu
Ionic motifs incorporated into polymers, such as ionomers, polyelectrolytes, polyampholytes, and poly(ionic liquid)s (PILs), serve as physical crosslinks through ionic interactions, presenting an effective molecular design for improving both the toughness and elastic modulus of the resulting polymer. However, in glassy polymers, ionic motifs, particularly organic base counterions, seldom effectively contribute to toughening mechanisms, as observed in soft materials. Here, we investigate the influence of tertiary and quaternary ammonium counterions on the mechanical properties of ionic comb polymers with a focus on the counterion incorporation ratio. We discovered a specific ion content range where only tertiary ammonium counterions, such as triheptylamine, improved both the toughness and Young’s modulus of a precursor polymer containing carboxylic acid groups and oligo(ethylene glycol) side chains. Fourier transform infrared (FT-IR) analysis revealed the presence of neutral amines in the tertiary ammonium systems, as evidenced by slightly less intense carboxylate peaks compared with the quaternary ammonium system peak intensities. Furthermore, rheological analysis revealed that tertiary counterions induced plasticization and reduced relaxation times up to the rubbery region. This study demonstrated the distinct mechanical effects of organic bases on glassy polymers. Schematic of the mechanical properties (toughness and Young’s modulus) of ionic comb polymers (ICP-baseX) with tertiary and quaternary ammonium counterions and varying base/COOH ratios.
{"title":"Tertiary ammonium counterions outperform quaternary ammonium counterions in ionic comb polymers: overcoming the trade-off between toughness and the elastic modulus","authors":"Daisuke Aoki, Kento Yasuda, Kotaro Uchiyama, Koji Arimitsu","doi":"10.1038/s41428-025-01061-5","DOIUrl":"10.1038/s41428-025-01061-5","url":null,"abstract":"Ionic motifs incorporated into polymers, such as ionomers, polyelectrolytes, polyampholytes, and poly(ionic liquid)s (PILs), serve as physical crosslinks through ionic interactions, presenting an effective molecular design for improving both the toughness and elastic modulus of the resulting polymer. However, in glassy polymers, ionic motifs, particularly organic base counterions, seldom effectively contribute to toughening mechanisms, as observed in soft materials. Here, we investigate the influence of tertiary and quaternary ammonium counterions on the mechanical properties of ionic comb polymers with a focus on the counterion incorporation ratio. We discovered a specific ion content range where only tertiary ammonium counterions, such as triheptylamine, improved both the toughness and Young’s modulus of a precursor polymer containing carboxylic acid groups and oligo(ethylene glycol) side chains. Fourier transform infrared (FT-IR) analysis revealed the presence of neutral amines in the tertiary ammonium systems, as evidenced by slightly less intense carboxylate peaks compared with the quaternary ammonium system peak intensities. Furthermore, rheological analysis revealed that tertiary counterions induced plasticization and reduced relaxation times up to the rubbery region. This study demonstrated the distinct mechanical effects of organic bases on glassy polymers. Schematic of the mechanical properties (toughness and Young’s modulus) of ionic comb polymers (ICP-baseX) with tertiary and quaternary ammonium counterions and varying base/COOH ratios.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 11","pages":"1195-1205"},"PeriodicalIF":2.7,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.comhttps://www.nature.com/articles/s41428-025-01061-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145436542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hollow silica spheres possess unique properties such as high surface area, low refractive index, and light weight because of their hollow cores. These traits make them ideal for various applications, particularly as sound absorption materials. In this study, hollow silica spheres and their polymer composites, which exhibit frequency-selective sound absorption properties, were developed. Hollow silica spheres were prepared using polymer core templates, followed by calcination, resulting in highly monodisperse spheres with a uniform size distribution. By incorporating these spheres into a polydimethylsiloxane (PDMS) matrix, we demonstrated that sound absorption peaks can be tuned by adjusting the filler content, allowing frequency-selective absorption—in sharp contrast to typical broadband-absorbing porous materials. Notably, the inclusion of hollow silica spheres significantly enhanced the optical transparency of the composite by reducing the refractive index mismatch at the interfaces. Our findings highlight the potential of transparent, monodisperse hollow silica sphere-based isotropic composites with precisely controlled acoustic responses as versatile materials for next-generation acoustic and optical applications. Monodisperse hollow silica spheres embedded in a PDMS matrix yield highly isotropic composites with tunable optical and acoustic properties. Their hollow structure enhances transparency by minimizing refractive index mismatch, while controlled filler content enables frequency-selective sound absorption. This study presents a strategy for designing multifunctional materials with structural isotropy and precisely tailored responses for optical and acoustic applications.
{"title":"Frequency-selective sound absorption in transparent polymer composites with monodisperse hollow silica spheres","authors":"Uiseok Hwang, Jaeuk Sung, Jakyeong Koo, Xin Yang, Jae-Do Nam, Soochan Kim","doi":"10.1038/s41428-025-01063-3","DOIUrl":"10.1038/s41428-025-01063-3","url":null,"abstract":"Hollow silica spheres possess unique properties such as high surface area, low refractive index, and light weight because of their hollow cores. These traits make them ideal for various applications, particularly as sound absorption materials. In this study, hollow silica spheres and their polymer composites, which exhibit frequency-selective sound absorption properties, were developed. Hollow silica spheres were prepared using polymer core templates, followed by calcination, resulting in highly monodisperse spheres with a uniform size distribution. By incorporating these spheres into a polydimethylsiloxane (PDMS) matrix, we demonstrated that sound absorption peaks can be tuned by adjusting the filler content, allowing frequency-selective absorption—in sharp contrast to typical broadband-absorbing porous materials. Notably, the inclusion of hollow silica spheres significantly enhanced the optical transparency of the composite by reducing the refractive index mismatch at the interfaces. Our findings highlight the potential of transparent, monodisperse hollow silica sphere-based isotropic composites with precisely controlled acoustic responses as versatile materials for next-generation acoustic and optical applications. Monodisperse hollow silica spheres embedded in a PDMS matrix yield highly isotropic composites with tunable optical and acoustic properties. Their hollow structure enhances transparency by minimizing refractive index mismatch, while controlled filler content enables frequency-selective sound absorption. This study presents a strategy for designing multifunctional materials with structural isotropy and precisely tailored responses for optical and acoustic applications.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 11","pages":"1287-1293"},"PeriodicalIF":2.7,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.comhttps://www.nature.com/articles/s41428-025-01063-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145436558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Various crosslinked PDMS films incorporating cyclic epoxy groups were prepared by UV-induced acid generation and thermal curation and evaluated as CO₂-selective permeable membranes. These free-standing, ultrathin PDMS films (~100 nm thick) were formed by crosslinking side-epoxy-PDMS, which contains multiple epoxy groups, and end-epoxy-PDMS, which has epoxy groups at the polymer ends only. Gas permeation tests revealed that the films crosslinked with end-epoxy-PDMS exhibited high CO₂ permeance. Specifically, the membrane composed of UV-crosslinked end-epoxy-PDMS (Mn = 20,000, thickness ~ 200 nm) achieved a CO₂ permeance of 5200 GPU and a CO₂/N₂ selectivity of 11.0. Reducing the membrane thickness increased the permeance without affecting selectivity. However, shortening the siloxane chain, using side-epoxy-PDMS, or reducing the linker length led to decreases in both permeance and selectivity. For example, side-epoxy-PDMS (Mn = 30,000, Si-H/O-Si-O ratio = 37%, thickness ~ 200 nm) had a CO₂ permeance of 400 GPU and a CO₂/N₂ selectivity of 1.16. These results indicate that a lower crosslinking density and longer end-epoxy-PDMS siloxane chains are advantageous for CO₂ dissolution and diffusion, resulting in superior CO₂ permeance and selectivity compared with composed of side-epoxy-PDMS. UV-crosslinked PDMS membranes with site-selective alicyclic epoxy units exhibited outstanding CO₂ permeance and selectivity. By comparing end- and side-functionalized PDMS structures, we reveal that low crosslinking density and long siloxane chains favor CO₂ diffusion. Ultrathin (~100 nm), freestanding films fabricated via photoacid-induced curing achieved a CO₂ permeance of up to 5200 GPU with a CO₂/N₂ selectivity of 11.0. This study demonstrates the potential of molecularly engineered siloxane networks for high-performance gas separation, especially in membrane-based direct air capture (m-DAC) applications.
{"title":"Photocrosslinked films composed of polydimethylsiloxane bearing alicyclic epoxy units and their CO₂-selective permeation properties","authors":"Shiori Hashiguchi, Masahiko Kawata, Takeo Nakano, Kimihiro Matsukawa, Masashi Kunitake","doi":"10.1038/s41428-025-01052-6","DOIUrl":"10.1038/s41428-025-01052-6","url":null,"abstract":"Various crosslinked PDMS films incorporating cyclic epoxy groups were prepared by UV-induced acid generation and thermal curation and evaluated as CO₂-selective permeable membranes. These free-standing, ultrathin PDMS films (~100 nm thick) were formed by crosslinking side-epoxy-PDMS, which contains multiple epoxy groups, and end-epoxy-PDMS, which has epoxy groups at the polymer ends only. Gas permeation tests revealed that the films crosslinked with end-epoxy-PDMS exhibited high CO₂ permeance. Specifically, the membrane composed of UV-crosslinked end-epoxy-PDMS (Mn = 20,000, thickness ~ 200 nm) achieved a CO₂ permeance of 5200 GPU and a CO₂/N₂ selectivity of 11.0. Reducing the membrane thickness increased the permeance without affecting selectivity. However, shortening the siloxane chain, using side-epoxy-PDMS, or reducing the linker length led to decreases in both permeance and selectivity. For example, side-epoxy-PDMS (Mn = 30,000, Si-H/O-Si-O ratio = 37%, thickness ~ 200 nm) had a CO₂ permeance of 400 GPU and a CO₂/N₂ selectivity of 1.16. These results indicate that a lower crosslinking density and longer end-epoxy-PDMS siloxane chains are advantageous for CO₂ dissolution and diffusion, resulting in superior CO₂ permeance and selectivity compared with composed of side-epoxy-PDMS. UV-crosslinked PDMS membranes with site-selective alicyclic epoxy units exhibited outstanding CO₂ permeance and selectivity. By comparing end- and side-functionalized PDMS structures, we reveal that low crosslinking density and long siloxane chains favor CO₂ diffusion. Ultrathin (~100 nm), freestanding films fabricated via photoacid-induced curing achieved a CO₂ permeance of up to 5200 GPU with a CO₂/N₂ selectivity of 11.0. This study demonstrates the potential of molecularly engineered siloxane networks for high-performance gas separation, especially in membrane-based direct air capture (m-DAC) applications.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 9","pages":"985-994"},"PeriodicalIF":2.7,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.comhttps://www.nature.com/articles/s41428-025-01052-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144990815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-06-02DOI: 10.1038/s41428-025-01059-z
Yuto Hongo, Yoshiro Kaneko
In this study, we successfully prepared soluble polymers via the tris(pentafluorophenyl)borane (BCF)-catalyzed hydrosilylation of dimethylhydrosilyl-functionalized cage octasiloxane (DMHS-OS) and acetone, followed by dehydrocarbon condensation polymerization (Piers–Rubinstzajn reaction) between the unreacted hydrosilyl (Si–H) groups and converted isopropoxysilyl (Si–OiPr) groups of DMHS-OS. Notably, polymer Poly(DMHS-OS)-5, formed at a feed molar ratio of Si–H groups to acetone of 8:5, exhibited a relatively high weight-average molecular weight (Mw = 2.11 × 104). On the basis of the 1H NMR, 29Si NMR, and gel permeation chromatography results, Poly(DMHS-OS)-5 consists of approximately 17–18 linked cage octasiloxane repeating units. Despite the presence of alkoxysilyl groups, such as Si–OiPr, in the side chains, immersion in purified water for 1 h did not affect the solubility of the polymer, indicating its good water stability. Thermogravimetric analysis revealed that the 10% weight loss temperature of Poly(DMHS-OS)-5 was 535 °C and only 21% weight loss occurred at 1000 °C, indicating exceptionally low thermal degradation. These findings highlight the remarkably high thermal stability of the soluble polymer Poly(DMHS-OS)-5. Soluble polymers were prepared by polymerizing dimethylhydrosilyl-functionalized cage octasiloxane (DMHS-OS) using a tris(pentafluorophenyl)borane (BCF) catalyst through hydrosilylation with acetone, followed by dehydrocarbon condensation. Poly(DMHS-OS)-5, formed at a feed molar ratio of Si–H groups in DMHS-OS to acetone of 8:5, exhibited a weight-average molecular weight (Mw) of 2.11 × 104 and consisted of ca. 17–18 linked DMHS-OS units. It demonstrated high thermal stability, with a 10% weight loss temperature (Td10) of 535 °C and a weight loss of only 21% at 1000 °C.
{"title":"Thermally stable soluble polymers prepared via the tris(pentafluorophenyl)borane-catalyzed polymerization of hydrosilyl-functionalized cage octasiloxane","authors":"Yuto Hongo, Yoshiro Kaneko","doi":"10.1038/s41428-025-01059-z","DOIUrl":"10.1038/s41428-025-01059-z","url":null,"abstract":"In this study, we successfully prepared soluble polymers via the tris(pentafluorophenyl)borane (BCF)-catalyzed hydrosilylation of dimethylhydrosilyl-functionalized cage octasiloxane (DMHS-OS) and acetone, followed by dehydrocarbon condensation polymerization (Piers–Rubinstzajn reaction) between the unreacted hydrosilyl (Si–H) groups and converted isopropoxysilyl (Si–OiPr) groups of DMHS-OS. Notably, polymer Poly(DMHS-OS)-5, formed at a feed molar ratio of Si–H groups to acetone of 8:5, exhibited a relatively high weight-average molecular weight (Mw = 2.11 × 104). On the basis of the 1H NMR, 29Si NMR, and gel permeation chromatography results, Poly(DMHS-OS)-5 consists of approximately 17–18 linked cage octasiloxane repeating units. Despite the presence of alkoxysilyl groups, such as Si–OiPr, in the side chains, immersion in purified water for 1 h did not affect the solubility of the polymer, indicating its good water stability. Thermogravimetric analysis revealed that the 10% weight loss temperature of Poly(DMHS-OS)-5 was 535 °C and only 21% weight loss occurred at 1000 °C, indicating exceptionally low thermal degradation. These findings highlight the remarkably high thermal stability of the soluble polymer Poly(DMHS-OS)-5. Soluble polymers were prepared by polymerizing dimethylhydrosilyl-functionalized cage octasiloxane (DMHS-OS) using a tris(pentafluorophenyl)borane (BCF) catalyst through hydrosilylation with acetone, followed by dehydrocarbon condensation. Poly(DMHS-OS)-5, formed at a feed molar ratio of Si–H groups in DMHS-OS to acetone of 8:5, exhibited a weight-average molecular weight (Mw) of 2.11 × 104 and consisted of ca. 17–18 linked DMHS-OS units. It demonstrated high thermal stability, with a 10% weight loss temperature (Td10) of 535 °C and a weight loss of only 21% at 1000 °C.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 9","pages":"975-984"},"PeriodicalIF":2.7,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144990847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-06-02DOI: 10.1038/s41428-025-01058-0
Quoc-Viet Do, Masayuki Yamaguchi, Toshio Tada, Vu Anh Doan
Structure development under a temperature gradient was studied using a miscible blend of styrene-butadiene rubber (SBR) and a tackifier, an oligomeric copolymer comprising mainly styrene and α-methyl styrene (AMS). AMS was found to be miscible with SBR at an AMS content of up to 30 parts per hundred rubber (phr) (23 wt.%) at temperatures below 120 °C. A blend sheet with a thickness of 1 mm was placed in a compression-molding machine, where the top and bottom plates were maintained at different temperatures, such as 120 °C/80 °C and 100 °C/60 °C. After 30 min, the AMS contents on both surfaces were characterized. The AMS content on the low temperature side was high, and vice versa, with no phase separation. Furthermore, the phase diagram of the SBR/AMS blends as a function of the blend composition and temperature was examined. The system was found to show lower critical solution temperature behavior, suggesting that the Flory–Huggins interaction parameter increases with temperature. Therefore, at low temperature, blends containing large amounts of AMB must have a low free energy, which may result in the different compositions of the surfaces after exposure to a temperature gradient. The segregation behavior of Styrene-Butadiene Rubber (SBR) and poly(α-methylstyrene) (AMS) under a temperature gradient is investigated in detail. SBR and AMS are found to be miscible at an AMS content of 30 phr (23 wt.%), as confirmed by dynamic mechanical analysis. After treatment under a temperature gradient, AMS is observed to segregate toward the surface exposed to the lower temperature, as detected by Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR). The underlying mechanism is further elucidated based on the phase diagram of the SBR/AMS system.
{"title":"Segregation behavior of a tackifier in styrene-butadiene rubber under a temperature gradient","authors":"Quoc-Viet Do, Masayuki Yamaguchi, Toshio Tada, Vu Anh Doan","doi":"10.1038/s41428-025-01058-0","DOIUrl":"10.1038/s41428-025-01058-0","url":null,"abstract":"Structure development under a temperature gradient was studied using a miscible blend of styrene-butadiene rubber (SBR) and a tackifier, an oligomeric copolymer comprising mainly styrene and α-methyl styrene (AMS). AMS was found to be miscible with SBR at an AMS content of up to 30 parts per hundred rubber (phr) (23 wt.%) at temperatures below 120 °C. A blend sheet with a thickness of 1 mm was placed in a compression-molding machine, where the top and bottom plates were maintained at different temperatures, such as 120 °C/80 °C and 100 °C/60 °C. After 30 min, the AMS contents on both surfaces were characterized. The AMS content on the low temperature side was high, and vice versa, with no phase separation. Furthermore, the phase diagram of the SBR/AMS blends as a function of the blend composition and temperature was examined. The system was found to show lower critical solution temperature behavior, suggesting that the Flory–Huggins interaction parameter increases with temperature. Therefore, at low temperature, blends containing large amounts of AMB must have a low free energy, which may result in the different compositions of the surfaces after exposure to a temperature gradient. The segregation behavior of Styrene-Butadiene Rubber (SBR) and poly(α-methylstyrene) (AMS) under a temperature gradient is investigated in detail. SBR and AMS are found to be miscible at an AMS content of 30 phr (23 wt.%), as confirmed by dynamic mechanical analysis. After treatment under a temperature gradient, AMS is observed to segregate toward the surface exposed to the lower temperature, as detected by Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR). The underlying mechanism is further elucidated based on the phase diagram of the SBR/AMS system.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 9","pages":"1025-1032"},"PeriodicalIF":2.7,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144990843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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