Polymer Journal最新文献

{"title":"Coarse-grained molecular dynamics simulation of oxidative aging of polymers -effect of free radical diffusivity -","authors":"Takato Ishida, Yuya Doi, Takashi Uneyama, Yuichi Masubuchi","doi":"10.1038/s41428-024-00942-5","DOIUrl":"10.1038/s41428-024-00942-5","url":null,"abstract":"Recently, we developed an oxidative aging simulation technique that explicitly considers the transport of radicals by combining oxidation kinetics with coarse-grained molecular dynamics [1]. The current study explores the role of the free radical diffusivity of oxidative aging in polymers, with a focus on its effects on the heterogeneity of spatiotemporal structures and reaction kinetics, through coarse-grained simulations. By examining two distinct systems, including a heterosystem with a high reaction rate and a quasi-homosystem with a low reaction rate, we investigated how the diffusivity of free radicals influences the oxidative aging process. We examined three different diffusivity levels of radicals. For the slowest case, the radical diffusivity is slightly faster than that of the single polymer segment, whereas for the fastest case, the radical diffuses infinitely faster than the polymers. The aging simulations revealed that the variations in free radical diffusivity quantitatively change the reaction kinetics and spatiotemporal structures without qualitatively altering the overall aging behavior. Specifically, in a heterosystem, lower radical diffusivity slows the oxidation kinetics by increasing fluctuations in the local conversion ratios. In contrast, in a quasi-homosystem, reduced radical diffusivity slightly amplifies the heterogeneity of structures in the early aging stages; however, in a high-conversion region, the aged state becomes homogeneous regardless of the degree of radical diffusivity. We recently developed an oxidative aging simulation that combines oxidation kinetics with coarse-grained molecular dynamics. This study examines free radical diffusivity in polymer aging, focusing on its impact on spatiotemporal structures and reaction kinetics. We explored two systems with varying reaction rates and three radical diffusivity levels, observing how changes in diffusivity affect aging. Our findings indicate that while radical diffusivity alters reaction kinetics and structures, it does not fundamentally change the aging scenarios.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"56 11","pages":"1069-1078"},"PeriodicalIF":2.3,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-00942-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141881791","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}

{"title":"Morphologies of polymer chains spun onto solid substrates","authors":"Yuma Morimitsu, Hisao Matsuno, Keiji Tanaka","doi":"10.1038/s41428-024-00937-2","DOIUrl":"10.1038/s41428-024-00937-2","url":null,"abstract":"External fields are often present when polymers contact solids, potentially affecting chain adsorption onto a substrate. The adsorbed chains, which are difficult to relax thermally, could semipermanently influence the dynamics of the surrounding chains and bulk chains. In this study, we examined the effect of a force field induced by spin coating on the adsorption of a model polymer chain, DNA. Observations using atomic force microscopy indicated that the morphologies of adsorbed chains were affected not only by the force field but also by the incubation time (tinc) after deposition and before spinning. A longer tinc caused a greater amount of chains to transition from being present in two-dimensional random coil states to stretched states. Conversely, shorter tinc values resulted in many chains being adsorbed in a stretched state. The orientations of the stretched chains reflected the presence of competition between the effects of the centrifugal force and those of the flow rate gradient. At tinc = 0, the adsorbed chains were stretched, and they exhibited many kinks. It was anticipated that this macromolecular information could aid in controlling buried morphologies near solid surfaces and in fabricating promising materials, such as polymer composites and layered organic devices. We investigated the effect of a force field induced by spin coating on the adsorption of a model polymer, DNA. Observations using atomic force microscopy indicated that the morphologies of adsorbed chains were affected not only by the force field but also by the incubation time (tinc) after deposition and before spinning. Shorter tinc values resulted in many chains being adsorbed in a stretched state. The orientations of the stretched chains reflected the presence of competition between the effects of the centrifugal force and those of the flow rate gradient.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"56 11","pages":"1041-1050"},"PeriodicalIF":2.3,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-00937-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141783836","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}

{"title":"Radical polymerization of alkenyl boronates and C–B bond transformation: polymer synthesis through side-chain replacement for overcoming synthetic limitations","authors":"Tsuyoshi Nishikawa","doi":"10.1038/s41428-024-00935-4","DOIUrl":"10.1038/s41428-024-00935-4","url":null,"abstract":"Vinyl polymers are typically synthesized through the addition polymerization of corresponding vinyl compounds. However, the polymerization ability significantly depends on the substituent on the vinyl moiety, resulting in various synthetic limitations in the molecular structure of vinyl polymers. Given the increasing societal demand for enhanced properties and functions of polymer materials, innovative synthetic technologies are required for developing next-generation polymers through flexible molecular design. The author has made considerable efforts to overcome these limitations in polymer synthesis by employing alkenyl boronates as monomers for radical polymerization. The resulting polymers bear boron on the main chain, allowing the replacement of boron side chains with other elements through the cleavage of carbon–boron bonds in postpolymerization transformations. This strategy, based on “side-chain replacement,” has enabled the synthesis of various polymers that were previously inaccessible. The review highlights the author’s recent discovery of the radical (co)polymerization ability of alkenylboronic acid derivatives and C–B bond-cleaving side-chain replacement in polymer reaction. The polymerization ability is attributed to the vacant p-orbital of boron, which can stabilize chain-growth radical species. In copolymerization and controlled polymerization, the boron monomer behaves as a relatively electron-rich and conjugated monomer. The boron attached to the polymer main chain was replaceable with other elements, providing access to various polymers of which synthesis is not straightforward, such as poly(α-methyl vinyl alcohol), poly(vinyl alcohol-co-styrene), and poly(ethylene-co-acrylate).","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"56 10","pages":"873-886"},"PeriodicalIF":2.3,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-00935-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141783773","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}

{"title":"Molecular dynamics simulation of the relationship between hydration and water mobilities around piperazine-immobilized polyvinyl alcohol membranes for CO2 capture","authors":"Ryo Nagumo, Ayami Shibata, Ikuo Taniguchi, Shuichi Iwata","doi":"10.1038/s41428-024-00936-3","DOIUrl":"10.1038/s41428-024-00936-3","url":null,"abstract":"The dynamic and structural properties of the water molecules in 3-(1-piperazinyl)-1,2-propanediol-containing polyvinyl alcohol membranes were analyzed by molecular dynamics simulations. The resulting curve of the coordination number with diffusivity yielded important insights into the changes in the state of the water molecules with the water content, clarifying a key factor in determining the membrane performance for CO2 separation.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"56 10","pages":"933-938"},"PeriodicalIF":2.3,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141783774","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}

{"title":"Advances in injectable hydrogels with biological and physicochemical functions for cell delivery","authors":"Akihiro Nishiguchi","doi":"10.1038/s41428-024-00934-5","DOIUrl":"10.1038/s41428-024-00934-5","url":null,"abstract":"Injectable hydrogels that can be administered via syringes have enormous potential as cell delivery carriers for cell transplantation therapy. Owing to their beneficial properties, including biocompatibility, biodegradability, tissue adhesion, and scaffold functions, injectable hydrogels can be used to improve the delivery efficacy and survival of transplanted cells posttransplantation. Moreover, delivery via injection does not require culture or invasive surgical procedures, leading to reduced costs, processing time, and patient burden. To develop injectable hydrogels for clinical translation, hydrogels have been functionalized using various biological and physicochemical engineering approaches to induce angiogenesis, suppress immune rejection, provide viscoelasticity, and allow pore formation for cell infiltration. This focus review discusses the design of optimal injectable hydrogels for cell delivery. Moreover, this focus review summarizes the different approaches available to improve the biological and physicochemical features of hydrogels, lists their impacts on cellular functions, and highlights their therapeutic efficacy. Injectable hydrogels hold promise as cell delivery carriers for cell transplantation therapy in regenerative medicine. Injectable hydrogels possess various benefits, including biocompatibility, biodegradability, tissue adhesive properties, scaffold functions, and minimal invasiveness. To overcome the barriers in clinical translation, biological and physicochemical functionalization, which can improve delivery efficacy to the target and graft survival posttransplantation, is desirable. This review discusses the strategies to design injectable hydrogels for cell delivery and summarizes the approaches available to improve the biological and physicochemical features of hydrogels.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"56 10","pages":"895-903"},"PeriodicalIF":2.3,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141568635","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}

{"title":"Controlled synthesis of cylindrical micelles via crystallization-driven self-assembly (CDSA) and applications","authors":"Sipradip Mahapatra, Pradip Dey, Goutam Ghosh","doi":"10.1038/s41428-024-00931-8","DOIUrl":"10.1038/s41428-024-00931-8","url":null,"abstract":"Recently, crystallization-driven living self-assembly (CDSA) has attracted much attention for its ability to generate 1D cylindrical micelles and mimic chain growth polymerization using seed micelles as nuclei, as this process allows for the continuous growth of polymeric micelles with well-defined and controlled 1D nanostructures. Researchers have developed different techniques, including self-seeding and seeded growth, to form cylindrical block comicelles using the principle of living CDSA. This method is beneficial for the generation of complex nanostructures, such as pentablock comicelles or patchy comicelles, with very low polydispersity. This review sheds light on the living CDSA method, which can be used to precisely control length, shape, and branching during the self-assembly of amphiphilic block copolymers (BCPs) in the solution phase, leading to the creation of monodisperse 1D micelles with a crystalline core and solvated corona in a modular fashion. This paper also highlights the growth kinetics underlying the synthesis of cylindrical micelles via CDSA and its application in various fields, such as drug delivery, optoelectronics, and catalysis, which have been discovered recently. Lastly, the prospects of CDSA and its potential impact on materials science and nanotechnology are discussed. This review sheds light on the living CDSA method, which can be used to precisely control length, shape, and branching during the self-assembly of amphiphilic block copolymers (BCPs) in the solution phase, leading to the creation of monodisperse 1D micelles with a crystalline core and solvated corona in a modular fashion. This paper also highlights the growth kinetics underlying the synthesis of cylindrical micelles via CDSA and its application in various fields, such as drug delivery, optoelectronics, and catalysis, which have been discovered recently.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"56 11","pages":"949-975"},"PeriodicalIF":2.3,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-00931-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141568633","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}

{"title":"Facile and efficient synthesis of N-benzyl chitosan via a one-pot reductive amination utilizing 2-picoline borane","authors":"Junpei Miyake","doi":"10.1038/s41428-024-00933-6","DOIUrl":"10.1038/s41428-024-00933-6","url":null,"abstract":"In this paper, the use of 2-picoline borane (pic-BH3) as a reducing agent for the reductive amination of chitosan is reported for the first time. By optimizing the feed molar ratio of chitosan, benzaldehyde and pic-BH3, a high yield of isolated N-benzyl chitosan with a nearly perfect degree of substitution is successfully obtained. This material has rarely been obtained with previous methods. The newly developed synthetic method herein has many advantages, including being more facile, more efficient, and less harmful than conventional methods; thus, this method is applicable to other aldehydes or ketones, leading to wide varieties of N-modified chitosan in the future. For the first time, this paper revealed that 2-picoline borane (pic-BH3) functioned well in the reductive amination of chitosan. Therefore, N-benzyl chitosan with a nearly perfect degree of substitution was successfully obtained, which has rarely been achieved by other synthetic methods. The new method herein has many advantages, including being more facile, more efficient, and less harmful than conventional methods; thus, this method is applicable to other aldehydes or ketones, leading to a wide variety of N-modified chitosan specimens with desirable degrees of substitution in the future.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"56 10","pages":"925-931"},"PeriodicalIF":2.3,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-00933-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141548144","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}

{"title":"Semiautomated experiment with a robotic system and data generation by foundation models for synthesis of polyamic acid particles","authors":"Kan Hatakeyama-Sato, Hiroki Ishikawa, Shinya Takaishi, Yasuhiko Igarashi, Yuta Nabae, Teruaki Hayakawa","doi":"10.1038/s41428-024-00930-9","DOIUrl":"10.1038/s41428-024-00930-9","url":null,"abstract":"A semiautomated system for synthesizing polyamic acid particles using a custom liquid-handling device and a robotic arm is proposed in this study. Integration of cameras and a multimodal large language model facilitates continuous monitoring and documentation, enhancing objectivity in synthetic experiments and enabling future advancements in experimental research. This study proposes a semiautomated system for synthesizing polyamic acid particles using a custom liquid-handling device and a robotic arm. Integrating cameras and a multimodal large language model enhances continuous monitoring and documentation, improving objectivity in synthetic experiments and enabling future advancements in research.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"56 11","pages":"977-986"},"PeriodicalIF":2.3,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-00930-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141503147","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}

{"title":"Improvement in the physical properties of poly(lactic acid)/thermoplastic starch blends using oligo(lactic acid)-grafted starch","authors":"Kazuki Shibasaki, Yu-I Hsu, Hiroshi Uyama","doi":"10.1038/s41428-024-00918-5","DOIUrl":"10.1038/s41428-024-00918-5","url":null,"abstract":"General-purpose petroleum-derived plastic remains in the environment for long periods and has significant impacts on oceans and land. Biodegradable and biomass plastics are being developed around the world as countermeasures. A poly(lactic acid) (PLA)/thermoplastic starch (TPS) blend is a promising ecofriendly alternative to biodegradable plastic made from plants. However, owing to the hydrophilicity of starch and the hydrophobicity of PLA, phase separation occurs between PLA and starch. Furthermore, PLA/TPS blends have poor water resistance because of the presence of starch, limiting their applications. In this study, to improve the affinity of PLA for starch, oligo(lactic acid)-grafted starch (OLAgSt) was synthesized as a compatibilizer for PLA/TPS blends, and the effect of its addition to PLA/TPS blends was evaluated. OLAgSt with different OLA molecular weights and degrees of substitution (DS) were synthesized, and their effects on PLA/TPS were compared. The results indicated that OLAgSt functioned as a good compatibilizer, improving the dispersibility of TPS in PLA with 4 wt% OLAgSt added to PLA/TPS and improving the water resistance. Moreover, the OLA molecular weight of OLAgSt was greater than that of DS. These results are expected to facilitate the development of PLA/TPS applications in the food packaging and biomedical fields. Blends of poly(lactic acid) (PLA) and thermoplastic starch (TPS) are promising biodegradable plastics, although their poor compatibility results in poor physical properties. In this study, oligo(lactic acid)-grafted starch (OLAgSt) was synthesized and added to PLA/TPS blends as a compatibilizer, and the physical properties of the obtained blends were evaluated. OLAgSt was synthesized by ring-opening polymerization of L-lactide using the hydroxy group of tapioca starch as an initiator. OLAgSt not only enhanced the dispersion of TPS within PLA, but also improved the biodegradability of the blend in a seawater environment.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"56 10","pages":"905-913"},"PeriodicalIF":2.3,"publicationDate":"2024-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-00918-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141528869","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}

{"title":"Phase diagram for the gelation of temperature-responsive and biocompatible poly(oligo ethylene glycol methyl ether methacrylate) polymers in aqueous free-radical polymerization reactions","authors":"Takuma Kureha, Takuto Hirayama, Taichi Nishi","doi":"10.1038/s41428-024-00929-2","DOIUrl":"10.1038/s41428-024-00929-2","url":null,"abstract":"In this study, gel-phase diagrams of temperature-responsive and biocompatible polymers were obtained, and the characteristic gelation behaviors of the polymers were examined. The polymers are based on three oligoethylene glycol methyl ether methacrylate (OEGMA) monomers with different numbers of ethylene oxide (EO) units, i.e., with side chains that differ in length. The gelation thresholds depend on the OEGMA and crosslinker concentrations as well as the side chain length. Long EO side chains fill the polymerization system and reduce the concentration of polymer overlap, resulting in a high ability to occupy the system. Furthermore, the EO side chains may engage in self-crosslinking, i.e., polymers can branch and grow from the side chains depending on their length, resulting in a high bond probability. Based on these unique behavior patterns, gelation occurs more readily as the length of the side chains increases. We also synthesized ultralow crosslinked pOEGMA gels by tuning the gelation conditions; these gels exhibited improved swelling capacity and temperature responsiveness. These results should facilitate the development of a synthesis strategy to control the physical properties and structures of these materials for advanced applications, such as biofilms, actuators, and carriers. The gel-phase diagrams of temperature-responsive and biocompatible polymers with ethylene oxide (EO) side chains that differ in length were obtained. The gelation thresholds of the polymers depend not only on the monomer and crosslinker concentrations but also on the EO side chain lengths. Long EO side chains reduce the polymer overlap concentration. Furthermore, the EO side chains can engage in self-crosslinking, i.e., polymers can grow from the side chains depending on their length. These unique behaviors indicate that gelation occurs more readily with increasing the side chain length.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"56 11","pages":"1017-1029"},"PeriodicalIF":2.3,"publicationDate":"2024-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-00929-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141503148","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}