The macroscopic mechanical properties of polyamides depend on their microscopic structural properties, such as the crystalline phase, lamellar thickness, and long period, which change depending on the heat treatment conditions. In this study, the relationships between the macroscopic mechanical properties and lamellar structures of polyamide 11 obtained from different heat treatments were investigated. Heat treatments include quench, isothermal, and quench–annealing conditions. Wide-angle X-ray scattering measurements indicated that different crystalline phases formed depending on the heat treatment conditions. Polarized optical microscopy and differential scanning calorimetry revealed spherulite and crystal morphologies that were not spherulite. Small-angle X-ray scattering revealed that the lamellar thickness and long period increased with the heat treatment temperature. With increasing the long period of lamellae, the number of stress transmitters, which are stress transfer factors (entanglements, loop chains, etc.) between lamellae, increases. The lamellar thickness and long period of polyamide 11 were ~1.5 times greater than that of polyamide 6 under similar heat treatment. In uniaxial tensile tests, polyamide 6 specimens heat-treated at high temperatures fractured and did not elongate. Polyamide 11 elongated without fracture. The thick lamellar and long-period structure of polyamide 11 obtained from heat treatments in this study might explain its excellent elongation until the late stage of deformation. The relationships between the macroscopic mechanical properties and lamellar structures of polyamide 11 obtained from different heat treatments were investigated. From the tensile tests, the maximum stress and strain at necking increase with the heat treatment temperature. WAXS measurements indicated that different crystalline phases formed depending on the heat treatment conditions. SAXS revealed that the lamellar thickness and long period increased with the heat treatment temperature. Based on these results, we elucidated that the macroscopic mechanical properties correlate with the lamellar thickness and long period.
聚酰胺的宏观机械特性取决于其微观结构特性，例如结晶相、薄片厚度和长周期，而这些特性会随着热处理条件的不同而发生变化。本研究探讨了不同热处理条件下聚酰胺 11 的宏观机械性能与薄片结构之间的关系。热处理包括淬火、等温和淬火-退火条件。广角 X 射线散射测量结果表明，不同的热处理条件会形成不同的结晶相。偏光光学显微镜和差示扫描量热法显示了球晶和非球晶的晶体形态。小角 X 射线散射显示，片层厚度和长周期随着热处理温度的升高而增加。随着薄片长周期的增加，薄片之间的应力传递因子（缠结、环链等）数量也随之增加。在类似的热处理条件下，聚酰胺 11 的薄片厚度和长周期是聚酰胺 6 的 1.5 倍。在单轴拉伸试验中，高温热处理的聚酰胺 6 试样会断裂，但不会拉长。聚酰胺 11 则拉长而没有断裂。本研究中通过热处理获得的聚酰胺 11 厚层和长周期结构可能是其直到变形后期都具有出色伸长率的原因。
{"title":"Structure and mechanical properties of biobased polyamide 11 specimens subjected to different heat treatments","authors":"Toyoshi Yoshida, Mei Touji, Hideaki Takagi, Nobutaka Shimizu, Noriyuki Igarashi, Shinichi Sakurai, Makoto Uchida, Yoshihisa Kaneko","doi":"10.1038/s41428-024-00924-7","DOIUrl":"10.1038/s41428-024-00924-7","url":null,"abstract":"The macroscopic mechanical properties of polyamides depend on their microscopic structural properties, such as the crystalline phase, lamellar thickness, and long period, which change depending on the heat treatment conditions. In this study, the relationships between the macroscopic mechanical properties and lamellar structures of polyamide 11 obtained from different heat treatments were investigated. Heat treatments include quench, isothermal, and quench–annealing conditions. Wide-angle X-ray scattering measurements indicated that different crystalline phases formed depending on the heat treatment conditions. Polarized optical microscopy and differential scanning calorimetry revealed spherulite and crystal morphologies that were not spherulite. Small-angle X-ray scattering revealed that the lamellar thickness and long period increased with the heat treatment temperature. With increasing the long period of lamellae, the number of stress transmitters, which are stress transfer factors (entanglements, loop chains, etc.) between lamellae, increases. The lamellar thickness and long period of polyamide 11 were ~1.5 times greater than that of polyamide 6 under similar heat treatment. In uniaxial tensile tests, polyamide 6 specimens heat-treated at high temperatures fractured and did not elongate. Polyamide 11 elongated without fracture. The thick lamellar and long-period structure of polyamide 11 obtained from heat treatments in this study might explain its excellent elongation until the late stage of deformation. The relationships between the macroscopic mechanical properties and lamellar structures of polyamide 11 obtained from different heat treatments were investigated. From the tensile tests, the maximum stress and strain at necking increase with the heat treatment temperature. WAXS measurements indicated that different crystalline phases formed depending on the heat treatment conditions. SAXS revealed that the lamellar thickness and long period increased with the heat treatment temperature. Based on these results, we elucidated that the macroscopic mechanical properties correlate with the lamellar thickness and long period.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"56 9","pages":"833-845"},"PeriodicalIF":2.3,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141251824","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}
We have investigated the self-assembly kinetics of silica nanoparticles (SNPs) into the polymer-like structure by time-resolved small-angle X-ray scattering (SAXS). The analysis of the SAXS data with a kinetic model revealed that the SNPs undergo self-assembly in a process akin to the step-growth polymerization of bifunctional monomers. This study offers a facile strategy to construct polymer-like structures from isotropic spherical nanoparticles.
我们通过时间分辨小角 X 射线散射（SAXS）研究了二氧化硅纳米颗粒（SNPs）自组装成聚合物状结构的动力学。利用动力学模型对 SAXS 数据进行分析后发现，SNP 的自组装过程类似于双功能单体的阶跃生长聚合过程。这项研究为利用各向同性球形纳米粒子构建类聚合物结构提供了一种简便的策略。
{"title":"Supracolloidal step-growth polymerization of isotropic silica nanoparticles: a time-resolved small-angle X-ray scattering study","authors":"Tatsuki Oishi, Ayae Sugawara-Narutaki, Rintaro Takahashi","doi":"10.1038/s41428-024-00922-9","DOIUrl":"10.1038/s41428-024-00922-9","url":null,"abstract":"We have investigated the self-assembly kinetics of silica nanoparticles (SNPs) into the polymer-like structure by time-resolved small-angle X-ray scattering (SAXS). The analysis of the SAXS data with a kinetic model revealed that the SNPs undergo self-assembly in a process akin to the step-growth polymerization of bifunctional monomers. This study offers a facile strategy to construct polymer-like structures from isotropic spherical nanoparticles.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"56 11","pages":"1089-1092"},"PeriodicalIF":2.3,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-00922-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141251819","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}
Endoscopic submucosal dissection (ESD) benefits patients in the early stages of cancer, but it poses various risks of complication. Strategies involving the application of clinically approved products to cover ulcers caused by ESD can reduce these complications, but the fixed nature of their properties limit the understanding of their effects on ulcer healing. This study was focused on Tetra–PEG gel, an innovative hydrogel with controllable physical properties made from a sulfhydryl–maleimide pair. The use of biocompatible polyethylene glycol (PEG) in Tetra–PEG gel may allow for its application as a biomaterial. The aims of our study were to identify the characteristics of a self-solidifying hydrogel for endoscopic application and to develop a new ulcer coating agent for post-ESD treatment. We developed a specialized double-lumen catheter and determined the optimal application conditions of the hydrogel. We examined the hydrodynamic properties of the gelling solutions and elucidated the pressure drop that occurred during device operation. Finally, by considering previous experimental results, we successfully applied the hydrogel to post-ESD ulcers in porcine stomachs. We believed that by further optimizing hydrogels with effectively controlled properties and by continuing to investigate them through animal experiments, we could expand our understanding of the relationships among material and ulcer healing properties and apply this knowledge to clinical applications. We explored the feasibility of Tetra-PEG gel, a controllable hydrogel, as a new biomaterial to develop a coating agent for post-ESD ulcers. We examined the optimal conditions for hydrogel application and developed a specialized catheter, then investigated its properties. Ultimately, we successfully used the optimized hydrogel and device to cover post-ESD ulcers in the porcine stomach. Further optimization of the hydrogel and ongoing research through animal experiments are expected to deepen our understanding of the material’s effects on ulcer healing and contribute to its clinical applications.
{"title":"Optimizing a self-solidifying hydrogel as an endoscopically deliverable hydrogel coating system: a proof-of-concept study on porcine endoscopic submucosal dissection-induced ulcers","authors":"Rina Cho, Hiroyuki Kamata, Yosuke Tsuji, Ayano Fujisawa, Yuko Miura, Shohei Ishikawa, Ren Sato, Takuya Katashima, Takamasa Sakai, Mitsuhiro Fujishiro","doi":"10.1038/s41428-024-00921-w","DOIUrl":"10.1038/s41428-024-00921-w","url":null,"abstract":"Endoscopic submucosal dissection (ESD) benefits patients in the early stages of cancer, but it poses various risks of complication. Strategies involving the application of clinically approved products to cover ulcers caused by ESD can reduce these complications, but the fixed nature of their properties limit the understanding of their effects on ulcer healing. This study was focused on Tetra–PEG gel, an innovative hydrogel with controllable physical properties made from a sulfhydryl–maleimide pair. The use of biocompatible polyethylene glycol (PEG) in Tetra–PEG gel may allow for its application as a biomaterial. The aims of our study were to identify the characteristics of a self-solidifying hydrogel for endoscopic application and to develop a new ulcer coating agent for post-ESD treatment. We developed a specialized double-lumen catheter and determined the optimal application conditions of the hydrogel. We examined the hydrodynamic properties of the gelling solutions and elucidated the pressure drop that occurred during device operation. Finally, by considering previous experimental results, we successfully applied the hydrogel to post-ESD ulcers in porcine stomachs. We believed that by further optimizing hydrogels with effectively controlled properties and by continuing to investigate them through animal experiments, we could expand our understanding of the relationships among material and ulcer healing properties and apply this knowledge to clinical applications. We explored the feasibility of Tetra-PEG gel, a controllable hydrogel, as a new biomaterial to develop a coating agent for post-ESD ulcers. We examined the optimal conditions for hydrogel application and developed a specialized catheter, then investigated its properties. Ultimately, we successfully used the optimized hydrogel and device to cover post-ESD ulcers in the porcine stomach. Further optimization of the hydrogel and ongoing research through animal experiments are expected to deepen our understanding of the material’s effects on ulcer healing and contribute to its clinical applications.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"56 9","pages":"855-863"},"PeriodicalIF":2.3,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-00921-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141189037","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 : 2024-05-29DOI: 10.1038/s41428-024-00920-x
Fumitaka Ishiwari, Yoshiaki Shoji, Colin J. Martin, Takanori Fukushima
Triptycene, a rigid propeller-shaped molecule, was first synthesized in the early 1940s. More recently, many triptycene-containing polymers and molecular assemblies have been developed for a wide range of applications, including guest recognition, material transport, separation, catalysis, and as device components. The advantages of triptycenes lie in their ability to introduce a variety of functional groups on their three-dimensional backbone, with changes in substitution patterns as well as the type of substituents present having a significant impact on the material properties. In this review, we describe the synthesis of triptycene derivatives and polymers, detailing selected examples of triptycene-containing functional polymers. We also focus on the construction of triptycene-based two-dimensional assemblies and polymers, where space-filling designs based on rigid propeller-shaped skeletons are essential. Through a thorough literature survey, future directions and possibilities for the development of triptycene-containing functional materials are discussed. Triptycene-containing polymers featuring a rigid propeller-shaped structure have attracted attention for a wide range of potential applications including guest recognition, material transports, separations, catalysis, and organic electronics. Herein, with a thorough literature survey, we present the synthesis of the various types of triptycenes that provide components for functional polymers. We particularly focus on triptycene-containing polymers and two-dimensional assemblies based on the space-filling design that uses nested packing. Future perspectives on the functionalities brought about by the design of triptycene-containing polymers and molecular assemblies are also discussed.
{"title":"Recent advances in structurally elaborate triptycenes, triptycene-containing polymers and assemblies: structures, functions and applications","authors":"Fumitaka Ishiwari, Yoshiaki Shoji, Colin J. Martin, Takanori Fukushima","doi":"10.1038/s41428-024-00920-x","DOIUrl":"10.1038/s41428-024-00920-x","url":null,"abstract":"Triptycene, a rigid propeller-shaped molecule, was first synthesized in the early 1940s. More recently, many triptycene-containing polymers and molecular assemblies have been developed for a wide range of applications, including guest recognition, material transport, separation, catalysis, and as device components. The advantages of triptycenes lie in their ability to introduce a variety of functional groups on their three-dimensional backbone, with changes in substitution patterns as well as the type of substituents present having a significant impact on the material properties. In this review, we describe the synthesis of triptycene derivatives and polymers, detailing selected examples of triptycene-containing functional polymers. We also focus on the construction of triptycene-based two-dimensional assemblies and polymers, where space-filling designs based on rigid propeller-shaped skeletons are essential. Through a thorough literature survey, future directions and possibilities for the development of triptycene-containing functional materials are discussed. Triptycene-containing polymers featuring a rigid propeller-shaped structure have attracted attention for a wide range of potential applications including guest recognition, material transports, separations, catalysis, and organic electronics. Herein, with a thorough literature survey, we present the synthesis of the various types of triptycenes that provide components for functional polymers. We particularly focus on triptycene-containing polymers and two-dimensional assemblies based on the space-filling design that uses nested packing. Future perspectives on the functionalities brought about by the design of triptycene-containing polymers and molecular assemblies are also discussed.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"56 9","pages":"791-818"},"PeriodicalIF":2.3,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-00920-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141166168","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}
This study examined the effects of loading amounts of a biobased plasticizer, namely, organic acid monoglyceride (OMG), on the formation of homocrystals (HCs) and stereocomplex crystals (SCs) in PLLA/PDLA (50/50) blends by means of differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD) and polarized optical microscopy (POM) observations. OMG at different concentrations was added to the PLLA/PDLA (50/50) blend from 0.5 to 5% in 0.5% increments. The addition of OMG was found to enhance SC formation while suppressing HC formation in both nonisothermal and isothermal experiments. The total suppression of HC formation and exclusive SC formation was achieved in the specimens with OMG contents higher than 3% after isothermal crystallization at 170 °C for 5 h. This result was confirmed by WAXD measurements of the specimens with 4 and 5% OMG, where only SC diffraction peaks were observed. In addition, the degree of crystallinity was found to be the same for the specimens with 0 and 5% OMG crystallized at 170 °C for 5 h. These findings imply that not only did the SC form exclusively but also that the presence of OMG actively accelerated its crystallization. The effects of an organic monoglyceride (OMG) plasticizer on the crystallization of the PLLA/PDLA (50/50) blend were investigated by examining the isothermal crystallization of the blend with different contents of OMG (1–5 wt%) using POM, DSC, and time-resolved WAXD. It was found that the increase of the OMG content promoted the exclusive formation of stereocomplex crystallites and enhanced its crystallinity while suppressing the formation of homocrystals.
{"title":"Exclusive formation of stereocomplex crystallites in PLLA/PDLA (50/50) blends by the addition of a plasticizer","authors":"Neimatallah Hosni Mohammed Mahmoud, Hideaki Takagi, Nobutaka Shimizu, Noriyuki Igarashi, Shinichi Sakurai","doi":"10.1038/s41428-024-00919-4","DOIUrl":"10.1038/s41428-024-00919-4","url":null,"abstract":"This study examined the effects of loading amounts of a biobased plasticizer, namely, organic acid monoglyceride (OMG), on the formation of homocrystals (HCs) and stereocomplex crystals (SCs) in PLLA/PDLA (50/50) blends by means of differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD) and polarized optical microscopy (POM) observations. OMG at different concentrations was added to the PLLA/PDLA (50/50) blend from 0.5 to 5% in 0.5% increments. The addition of OMG was found to enhance SC formation while suppressing HC formation in both nonisothermal and isothermal experiments. The total suppression of HC formation and exclusive SC formation was achieved in the specimens with OMG contents higher than 3% after isothermal crystallization at 170 °C for 5 h. This result was confirmed by WAXD measurements of the specimens with 4 and 5% OMG, where only SC diffraction peaks were observed. In addition, the degree of crystallinity was found to be the same for the specimens with 0 and 5% OMG crystallized at 170 °C for 5 h. These findings imply that not only did the SC form exclusively but also that the presence of OMG actively accelerated its crystallization. The effects of an organic monoglyceride (OMG) plasticizer on the crystallization of the PLLA/PDLA (50/50) blend were investigated by examining the isothermal crystallization of the blend with different contents of OMG (1–5 wt%) using POM, DSC, and time-resolved WAXD. It was found that the increase of the OMG content promoted the exclusive formation of stereocomplex crystallites and enhanced its crystallinity while suppressing the formation of homocrystals.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"56 9","pages":"819-831"},"PeriodicalIF":2.3,"publicationDate":"2024-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141099580","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 : 2024-05-23DOI: 10.1038/s41428-024-00916-7
Katsuhisa Yano, Akinori Takasu, Hiroshi Eguchi
We prepared the dialkynyl monomers 1,4-butanediol dipropiolate, meso-erythritol dipropiolate, and isomannide dipropiolate (IMDP) via the reactions of 1,4-butanediol, meso-erythritol, and isomannide, respectively, with propiolic acid. The thiol-Michael polyaddition of three dialkynyl monomers with several dithiols, namely, 1,4-butanedithiol, ethylene bis(thioglycolate), 3,6-dioxa-1,8-octanedithiol, D,L-dithiothreitol, and D-2,5-di-O-(2-mercaptoacetate)-1,4:3,6-dianhydromannitol (MAIM), proceeded in chloroform, tetrahydrofuran, or N,N-dimethylformamide (25 °C) using triethylamine as the catalyst to give unsaturated poly(ester-thioether)s with the expected structures (Mn, 2.4 × 103 to 22.6 × 103; molecular dispersity index [Mw/Mn], 1.26–2.00). All of the poly(ester-thioester)s had single glass-transition temperature (Tg) values between −27 and 49 °C. While the rigid main chains improved the glass transition temperature, all of the poly(ester-thioester)s showed apparent enzymatic hydrolysis by lipase but low biodegradability in biodegradation tests using activated sludge. The poly(IMDP-alt-MAIM) with the highest biobased degree (55%) showed the highest biodegradability (10%) and the highest Tg (49 °C), suggesting that dianhydrosugars are suitable as biomass for improving biodegradability as well as thermal properties. The thiol-Michael polyaddition of three dialkynyl monomers with several dithiols proceeded using triethylamine as the catalyst to give unsaturated poly(ester-thioether)s with the expected structures (Mn, 2.4 × 103 to 22.6 × 103; molecular dispersity index [Mw/Mn], 1.26–2.00). All of the poly(ester-thioester)s had single glass-transition temperature values between −27 and 49 °C. While the rigid main chains improved the glass transition temperature, all of the poly(ester-thioester)s showed apparent enzymatic hydrolysis by lipase but low biodegradability in biodegradation tests using activated sludge.
{"title":"Biodegradability of unsaturated poly(ester-thioether)s synthesized by thiol-yne reactions","authors":"Katsuhisa Yano, Akinori Takasu, Hiroshi Eguchi","doi":"10.1038/s41428-024-00916-7","DOIUrl":"10.1038/s41428-024-00916-7","url":null,"abstract":"We prepared the dialkynyl monomers 1,4-butanediol dipropiolate, meso-erythritol dipropiolate, and isomannide dipropiolate (IMDP) via the reactions of 1,4-butanediol, meso-erythritol, and isomannide, respectively, with propiolic acid. The thiol-Michael polyaddition of three dialkynyl monomers with several dithiols, namely, 1,4-butanedithiol, ethylene bis(thioglycolate), 3,6-dioxa-1,8-octanedithiol, D,L-dithiothreitol, and D-2,5-di-O-(2-mercaptoacetate)-1,4:3,6-dianhydromannitol (MAIM), proceeded in chloroform, tetrahydrofuran, or N,N-dimethylformamide (25 °C) using triethylamine as the catalyst to give unsaturated poly(ester-thioether)s with the expected structures (Mn, 2.4 × 103 to 22.6 × 103; molecular dispersity index [Mw/Mn], 1.26–2.00). All of the poly(ester-thioester)s had single glass-transition temperature (Tg) values between −27 and 49 °C. While the rigid main chains improved the glass transition temperature, all of the poly(ester-thioester)s showed apparent enzymatic hydrolysis by lipase but low biodegradability in biodegradation tests using activated sludge. The poly(IMDP-alt-MAIM) with the highest biobased degree (55%) showed the highest biodegradability (10%) and the highest Tg (49 °C), suggesting that dianhydrosugars are suitable as biomass for improving biodegradability as well as thermal properties. The thiol-Michael polyaddition of three dialkynyl monomers with several dithiols proceeded using triethylamine as the catalyst to give unsaturated poly(ester-thioether)s with the expected structures (Mn, 2.4 × 103 to 22.6 × 103; molecular dispersity index [Mw/Mn], 1.26–2.00). All of the poly(ester-thioester)s had single glass-transition temperature values between −27 and 49 °C. While the rigid main chains improved the glass transition temperature, all of the poly(ester-thioester)s showed apparent enzymatic hydrolysis by lipase but low biodegradability in biodegradation tests using activated sludge.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"56 8","pages":"725-734"},"PeriodicalIF":2.3,"publicationDate":"2024-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-00916-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141103440","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}
The Suzuki–Miyaura coupling reaction of BrC6H4-SiRR’-C6H4Br 1 with phenylboronic acid 3 in the presence of tBu3PPd precatalyst 4 and CsF/18-crown-6 produced a phenyl-disubstituted product, indicating that the Pd catalyst underwent catalyst transfer on the silylene group. The polycondensation of 1 and phenylenediboronic acid 2 yielded cyclic polymers even when excess 1 was used. The obtained cyclic polymers containing the silylene group showed stronger fluorescence in solution than did the methylene counterpart.
{"title":"Intramolecular catalyst transfer on silylene group between benzene rings in Suzuki–Miyaura coupling reaction: synthesis of σ−π conjugated cyclic polymers","authors":"Natsumi Harada, Rina Yachida, Ryusuke Shimada, Takayoshi Katoh, Sena Hashimoto, Yoshihiro Ohta, Izumi Iwakura, Tsutomu Yokozawa","doi":"10.1038/s41428-024-00913-w","DOIUrl":"10.1038/s41428-024-00913-w","url":null,"abstract":"The Suzuki–Miyaura coupling reaction of BrC6H4-SiRR’-C6H4Br 1 with phenylboronic acid 3 in the presence of tBu3PPd precatalyst 4 and CsF/18-crown-6 produced a phenyl-disubstituted product, indicating that the Pd catalyst underwent catalyst transfer on the silylene group. The polycondensation of 1 and phenylenediboronic acid 2 yielded cyclic polymers even when excess 1 was used. The obtained cyclic polymers containing the silylene group showed stronger fluorescence in solution than did the methylene counterpart.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"56 8","pages":"777-781"},"PeriodicalIF":2.3,"publicationDate":"2024-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141115933","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}
In this study, we show that doping lanthanides into lamellar crystals reorganizes the lamellar structure and dramatically changes the crystal morphology. Azo-DA, a compound with azobenzene derivatives and carboxylic acids at both ends of the diacetylene moiety, formed plate-like lamellar crystals. The doping of holmium (Ho), a lanthanide, into the film obtained by stacking Azo-DA lamellar crystals, promoted a dramatic change in crystal morphology, resulting in the formation of an Azo-DA/Ho film with a radial lamellar crystal structure. A detailed investigation of the crystal growth process revealed that Azo-DA/Ho, which is slightly formed in the solution phase during Ho doping, acts as a pseudonucleating agent and dramatically changes the morphology of the lamellar crystals. Additionally, the morphological changes in the lamellar crystal films significantly changed the surface properties of the films, such as their appearance and water repellency. Similar morphological changes in lamellar crystals were induced when other lanthanide elements were used instead of Ho, and the type of lanthanide dopant can affect the magnetic properties of the films. Doping lanthanides into lamellar crystals of diacetylene derivatives with terminal carboxylic acids reorganized the lamellar structure and dramatically changed the crystal morphology. Detailed investigation of the crystal growth process revealed that the complexes of lanthanide and diacetylene derivatives, which are slightly formed in the solution phase during lanthanide doping, may act as a pseudonuclear agent and change the morphology of the lamellar crystals. Furthermore, the morphology changes of the lamellar crystal films significantly altered surface properties such as film appearance and water repellency.
本研究表明，在片晶中掺入镧系元素可重组片晶结构并显著改变晶体形态。偶氮-DA（一种在二乙炔分子两端含有偶氮苯衍生物和羧酸的化合物）形成了板状薄片晶体。将镧系元素钬（Ho）掺杂到由偶氮-DA 片状晶体堆叠而成的薄膜中后，晶体形态发生了巨大变化，形成了具有径向片状晶体结构的偶氮-DA/Ho 薄膜。对晶体生长过程的详细研究表明，在掺杂 Ho 的过程中，溶液相中轻微形成的 Azo-DA/Ho 起到了假核剂的作用，并显著改变了片状晶体的形态。此外，片状晶体薄膜的形态变化显著改变了薄膜的表面特性，如外观和憎水性。当使用其他镧系元素代替 Ho 时，薄片晶体也会发生类似的形态变化，而且镧系元素掺杂剂的类型也会影响薄膜的磁性能。在带有末端羧酸的二乙炔衍生物片层晶体中掺入镧系元素后，片层结构发生了重组，晶体形态也发生了显著变化。对晶体生长过程的详细研究表明，镧系元素与二乙炔衍生物的络合物在镧系元素掺杂过程中会在溶液相中轻微形成，这些络合物可能作为一种伪核剂改变了片晶的形态。此外，片状晶体薄膜的形态变化显著改变了薄膜的外观和憎水性等表面特性。
{"title":"Changes in crystal morphology induced by lanthanide doping into diacetylene lamellar crystals","authors":"Michinari Kohri, Sojiro Isomura, Kyoka Tachibana, Ryota Hikichi, Yuya Oaki, Hiroki Wadati, Hirofumi Kanoh, Keiki Kishikawa","doi":"10.1038/s41428-024-00917-6","DOIUrl":"10.1038/s41428-024-00917-6","url":null,"abstract":"In this study, we show that doping lanthanides into lamellar crystals reorganizes the lamellar structure and dramatically changes the crystal morphology. Azo-DA, a compound with azobenzene derivatives and carboxylic acids at both ends of the diacetylene moiety, formed plate-like lamellar crystals. The doping of holmium (Ho), a lanthanide, into the film obtained by stacking Azo-DA lamellar crystals, promoted a dramatic change in crystal morphology, resulting in the formation of an Azo-DA/Ho film with a radial lamellar crystal structure. A detailed investigation of the crystal growth process revealed that Azo-DA/Ho, which is slightly formed in the solution phase during Ho doping, acts as a pseudonucleating agent and dramatically changes the morphology of the lamellar crystals. Additionally, the morphological changes in the lamellar crystal films significantly changed the surface properties of the films, such as their appearance and water repellency. Similar morphological changes in lamellar crystals were induced when other lanthanide elements were used instead of Ho, and the type of lanthanide dopant can affect the magnetic properties of the films. Doping lanthanides into lamellar crystals of diacetylene derivatives with terminal carboxylic acids reorganized the lamellar structure and dramatically changed the crystal morphology. Detailed investigation of the crystal growth process revealed that the complexes of lanthanide and diacetylene derivatives, which are slightly formed in the solution phase during lanthanide doping, may act as a pseudonuclear agent and change the morphology of the lamellar crystals. Furthermore, the morphology changes of the lamellar crystal films significantly altered surface properties such as film appearance and water repellency.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"56 8","pages":"765-775"},"PeriodicalIF":2.3,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-00917-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140976187","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 : 2024-05-15DOI: 10.1038/s41428-024-00915-8
Mao Hirata, Tomoki Yoshimatsu, Shin-ichi Matsuoka, Susumu Kawauchi, Masato Suzuki
Three cyclic oxoester-thioester hybrid monomers, 1 (3-methyl-1,4-oxathiane-2,5-dione), 2 (6-methyl-1,4-oxathiane-2,5-dione), and 3 (3,6-dimethyl-1,4-oxathiane-2,5-dione), were studied for anionic and cationic ring-opening polymerizations. These monomers are six-membered cyclic cross-dimers corresponding to combinations of glycolic and lactic acids with their thiol analogs. Anionic polymerizations using thiol as the initiator and 2,6-lutidine as the base catalyst were successful for the chemoselective cleavage of the thioester with the thiol propagating end. The polymerizability increased in the order of 3 < 1 < 2, which was in good agreement with the increasing ring strain order evaluated by Density Functional Theory calculations. The living character, to some extent, was suggested by the postpolymerization reactions, which involved a two-stage feed of the monomers and a thiol-ene terminal coupling reaction to form a block copolymer with PEG. Additionally, it was found that the polymerization took place in 2,6-lutidine without a thiol initiator and produced macrocyclic polymers. The cationic polymerizations took place with the aid of CF3SO3H and benzyl alcohol but involved side reactions with low chemoselective ring cleavage. The thioester unit caused the polymers to exhibit a lower Tg with greater thermal and photo degradability. Three cyclic oxoester-thioester hybrid monomers were studied for anionic and cationic ring-opening polymerizations. Anionic polymerizations using thiol with 2,6-lutidine were successful for the chemoselective cleavage of the thioester with the thiol propagating end, exhibiting the living character to some extent. The polymerization in 2,6-lutidine without an initiator produced macrocyclic polymers. The cationic polymerizations occurred with the aid of CF3SO3H and benzyl alcohol but involved side reactions with low chemoselective ring cleavage. The thioester unit caused the polymers to exhibit a lower Tg with greater thermal and photo degradability.
{"title":"Ring-opening polymerization of six-membered cyclic hybrid dimers composed of an oxoester and thioester","authors":"Mao Hirata, Tomoki Yoshimatsu, Shin-ichi Matsuoka, Susumu Kawauchi, Masato Suzuki","doi":"10.1038/s41428-024-00915-8","DOIUrl":"10.1038/s41428-024-00915-8","url":null,"abstract":"Three cyclic oxoester-thioester hybrid monomers, 1 (3-methyl-1,4-oxathiane-2,5-dione), 2 (6-methyl-1,4-oxathiane-2,5-dione), and 3 (3,6-dimethyl-1,4-oxathiane-2,5-dione), were studied for anionic and cationic ring-opening polymerizations. These monomers are six-membered cyclic cross-dimers corresponding to combinations of glycolic and lactic acids with their thiol analogs. Anionic polymerizations using thiol as the initiator and 2,6-lutidine as the base catalyst were successful for the chemoselective cleavage of the thioester with the thiol propagating end. The polymerizability increased in the order of 3 < 1 < 2, which was in good agreement with the increasing ring strain order evaluated by Density Functional Theory calculations. The living character, to some extent, was suggested by the postpolymerization reactions, which involved a two-stage feed of the monomers and a thiol-ene terminal coupling reaction to form a block copolymer with PEG. Additionally, it was found that the polymerization took place in 2,6-lutidine without a thiol initiator and produced macrocyclic polymers. The cationic polymerizations took place with the aid of CF3SO3H and benzyl alcohol but involved side reactions with low chemoselective ring cleavage. The thioester unit caused the polymers to exhibit a lower Tg with greater thermal and photo degradability. Three cyclic oxoester-thioester hybrid monomers were studied for anionic and cationic ring-opening polymerizations. Anionic polymerizations using thiol with 2,6-lutidine were successful for the chemoselective cleavage of the thioester with the thiol propagating end, exhibiting the living character to some extent. The polymerization in 2,6-lutidine without an initiator produced macrocyclic polymers. The cationic polymerizations occurred with the aid of CF3SO3H and benzyl alcohol but involved side reactions with low chemoselective ring cleavage. The thioester unit caused the polymers to exhibit a lower Tg with greater thermal and photo degradability.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"56 8","pages":"711-723"},"PeriodicalIF":2.3,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-00915-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140972844","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}
A simple method to finely control the thermoresponsive properties of polymers over a wide range of temperatures is to enhance the versatility of the thermoresponsive polymers. One such useful technique is the radical copolymerization of two types of monomers with similar copolymerization reactivities, which allows the hydrophilicity/hydrophobicity balance in the polymer structure to be easily tuned. In this study, we focused on a urethane-containing monomer as the key compound, which can be easily obtained by the reaction between an isocyanate and a hydrophilic precursor monomer containing a hydroxy group. A variety of urethane-embedded acrylamide monomers with different alkyl side chains (ethyl: EtUAAm, n-butyl: BuUAAm, and n-hexyl: HexUAAm) were synthesized from 2-hydroxyethylacrylamide (HEAAm) and alkyl isocyanates. Copolymers of HEAAm and EtUAAm with different compositions were prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization. The obtained copolymer with a high urethane composition (>67%) exhibited a lower critical solution temperature (LCST)-type thermoresponse in water due to the hydrophobic interaction and hydrogen bonding derived from the urethane side groups. The response temperature could be widely varied by altering the composition, molecular weight, end groups and alkyl side chains of the urethane monomer. Simple control of the thermoresponsive properties of polymers in water over a broad range is achieved by using a designed urethane-containing acrylamide monomer in combination with a hydroxy-containing precursor monomer, which forms a statistical sequence due to its similar backbone. The copolymers exhibited a lower critical solution temperature-type responsive behavior in water, and the effects of structural factors such as composition, molecular weight, end groups and side-chain structure in urethane monomers were systematically evaluated.
{"title":"Facile synthesis of acrylamide derivative copolymers with side urethane groups for systematic variation of the thermoresponsive behavior","authors":"Shohei Ida, Ryu Hashiguchi, Yusuke Murai, Kaito Nakamura, Kazuki Yano, Shokyoku Kanaoka","doi":"10.1038/s41428-024-00914-9","DOIUrl":"10.1038/s41428-024-00914-9","url":null,"abstract":"A simple method to finely control the thermoresponsive properties of polymers over a wide range of temperatures is to enhance the versatility of the thermoresponsive polymers. One such useful technique is the radical copolymerization of two types of monomers with similar copolymerization reactivities, which allows the hydrophilicity/hydrophobicity balance in the polymer structure to be easily tuned. In this study, we focused on a urethane-containing monomer as the key compound, which can be easily obtained by the reaction between an isocyanate and a hydrophilic precursor monomer containing a hydroxy group. A variety of urethane-embedded acrylamide monomers with different alkyl side chains (ethyl: EtUAAm, n-butyl: BuUAAm, and n-hexyl: HexUAAm) were synthesized from 2-hydroxyethylacrylamide (HEAAm) and alkyl isocyanates. Copolymers of HEAAm and EtUAAm with different compositions were prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization. The obtained copolymer with a high urethane composition (>67%) exhibited a lower critical solution temperature (LCST)-type thermoresponse in water due to the hydrophobic interaction and hydrogen bonding derived from the urethane side groups. The response temperature could be widely varied by altering the composition, molecular weight, end groups and alkyl side chains of the urethane monomer. Simple control of the thermoresponsive properties of polymers in water over a broad range is achieved by using a designed urethane-containing acrylamide monomer in combination with a hydroxy-containing precursor monomer, which forms a statistical sequence due to its similar backbone. The copolymers exhibited a lower critical solution temperature-type responsive behavior in water, and the effects of structural factors such as composition, molecular weight, end groups and side-chain structure in urethane monomers were systematically evaluated.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"56 8","pages":"735-743"},"PeriodicalIF":2.3,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140883041","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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