Polymer Journal最新文献

{"title":"Understanding vitrimer properties through various aspects of inhomogeneity","authors":"Mikihiro Hayashi","doi":"10.1038/s41428-024-00990-x","DOIUrl":"10.1038/s41428-024-00990-x","url":null,"abstract":"Vitrimers represent a unique class of cross-linked materials characterized by an associative bond exchange mechanism within their polymeric network structure. This bond exchange facilitates the diffusion of network chains upon the application of suitable stimuli, typically heat, thus enabling specific vitrimer properties such as stress relaxation and creep. Recent reviews have extensively documented the diverse molecular designs and valuable sustainable functionalities achieved through this nature of bond exchange. Numerous fundamental studies have focused on developing tuning methods for vitrimer properties, utilizing model vitrimers that assume homogeneous network structures with uniformly distributed bond exchange units. In contrast, some research groups currently have deliberately engineered inhomogeneous network structures, characterized by highly localized bond exchangeable units and the presence of constraints imposed by permanent cross-links. In this review, we emphasize the significance of inhomogeneous network systems as potential avenues for the versatile tuning of vitrimer properties, which could contribute to a deeper understanding of these materials. Vitrimers are cross-linked materials featuring an associative bond exchange mechanism that allows network chain diffusion in response to stimuli like heat, leading to properties such as stress relaxation and creep. While numerous studies focus on tuning vitrimer properties using model systems with homogeneous structures, some researchers have engineered inhomogeneous networks with localized bond exchange units and constraints from permanent cross-links. This review highlights the significance of inhomogeneous network structures for broad designing of vitrimer properties.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 4","pages":"343-355"},"PeriodicalIF":2.3,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-00990-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143787325","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 simulations of the mechanical properties of dissociative dynamic bond elastomers with different binding-site sequences","authors":"Yusuke Yasuda, Shintaro Nakagawa, Hirohiko Houjou, Naoko Yoshie, Hiroshi Morita","doi":"10.1038/s41428-024-00985-8","DOIUrl":"10.1038/s41428-024-00985-8","url":null,"abstract":"Dynamic bond elastomers are attracting attention because of their self-healing properties and toughness. However, understanding the factors that influence their mechanical properties remains challenging because their unique crosslinking structures lead to properties that are not well explained by classical rubber elasticity theory. This study utilized coarse-grained molecular dynamics simulations to investigate the effects of the one-dimensional sequence of binding sites and reaction time prior to elongation on the mechanical properties of dissociative dynamic bond elastomers. Uniaxial elongation simulations of systems with random and regular sequences revealed the existence of kinetically and thermodynamically controlled crosslinking structures depending on the reaction time. Notably, elastomers with a regular sequence and shorter reaction time displayed a higher modulus, which was attributed to an increased ratio of interchain crosslinks to total crosslinks. These findings offer novel insights into the structural determinants of the mechanical behavior of dynamic bond elastomers. Dynamic bond elastomers are attracting attention because of their self-healing properties and toughness. Using coarse-grained molecular dynamics simulations, we studied how the sequence of binding sites and reaction time before elongation affect their mechanical properties. Our simulations with random, regular, and semiregular sequences indicated that reaction time influences the formation of crosslinking structures. Elastomers with a regular sequence and shorter reaction time had a higher modulus due to more interchain crosslinks. These findings provide new insights into the mechanical behavior of dynamic bond elastomers.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 4","pages":"467-475"},"PeriodicalIF":2.3,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-00985-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143787398","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":"Reversible modulation of polymer chain mobility by selective cage opening and closing of pendant boratrane units","authors":"Akira Takahashi, Masahiro Yamanishi, Atsushi Kameyama, Hideyuki Otsuka","doi":"10.1038/s41428-024-00986-7","DOIUrl":"10.1038/s41428-024-00986-7","url":null,"abstract":"As a simple and versatile methodology for large modulation of polymer chain mobility, we report the selective opening and closing reactions of cage-shaped triethanolamine borate (TEAB) at polymer side chains and their effect on the thermal properties of the parent polymers. A series of TEAB-pendant polymethacrylates was synthesized by common free-radical polymerization using TEAB-containing methacrylate. Boron vertex removal from the pendant TEAB groups proceeded quantitatively via hydrolysis at room temperature to afford triethanolamine (TEA), an open cage structure. Differential scanning calorimetry revealed that the pendant TEAB/TEA interconversion induces a large variation in the glass transition temperature (Tg) of the parent polymers up to 166 °C, as a result of the contrasting conformational flexibility of the rigid TEAB and flexible TEA. Regeneration of the pendant TEAB group (cage closing) also proceeded in a highly selective manner by adding a commercially available borate ester to the TEA-pendant polymer. The mechanism underlying the high reaction selectivity was investigated using density functional theory calculations. The borated product showed a comparable Tg to that of the pristine TEAB-pendant polymer, demonstrating the efficiency of TEAB/TEA interconversion for reversible and large modulation of polymer chain flexibility. Selective opening and closing reactions of cage-shaped triethanolamine borate (TEAB) at polymer side chains and their effect on the thermal properties of the parent polymers are reported. The conversion of TEAB-pendant polymethacrylates into the triethanolamine (TEA) counterparts was quantitatively achieved by hydrolysis of the pendant TEAB groups. The side chain conversion resulted in a large variation in glass transition temperature (Tg). Regeneration of pendant TEAB group also proceeded in a highly selective manner and almost recover the original Tg, demonstrating the reversible and large modulation of polymer chain flexibility.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 3","pages":"259-268"},"PeriodicalIF":2.3,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-00986-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143555243","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":"Degradation of stable thermosetting epoxy resins mediated by bases in amide solvents","authors":"Yasunori Minami, Tomoo Tsuyuki, Hayato Ishikawa, Yoshihiro Shimoyama, Kazuhiko Sato, Masaru Yoshida","doi":"10.1038/s41428-024-00979-6","DOIUrl":"10.1038/s41428-024-00979-6","url":null,"abstract":"Thermosetting epoxy resins are widely used in our society for adhesives, electronic devices, and building materials owing to their hardness and chemical stability; however, their robustness hinders their ability to chemically degrade to monomers and related low-molecular-weight molecules. Herein, we report the degradation of various thermosetting epoxy resins prepared from bisphenol A diglycidyl ether as a typical epoxy agent and various curing agents, such as diamino arenes, dithiols, and acid anhydrides. The degradation proceeded smoothly when sodium tert-butoxide was used as an activator in a 1,3-dimethyl-2-imidazolidinone solvent at 150 °C to form bisphenol A as a monomer precursor in high yields without any pretreatment. The proposed degradation method was successfully applied to cross-linked thermosetting epoxy resins derived from 4,4’-diaminodiphenylsulfone, a heat-resistant curing agent, commercially available adhesives, and carbon fiber-reinforced composite materials. When composite materials are used, the carbon fibers can be recovered intact. The degradation of various thermosetting epoxy resins prepared from bisphenol A diglycidyl ether as a typical epoxy agent and various curing agents, such as diamino arenes, dithiols, and acid anhydrides proceeded smoothly with sodium tert-butoxide in 1,3-dimethyl-2-imidazolidinone (DMI) solvent at 150 °C to form bisphenol A in high yields. Amide solvents effectively promoted depolymerization and allowed insoluble cross-linked thermosetting epoxy resins to undergo the reaction.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 2","pages":"149-162"},"PeriodicalIF":2.3,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-00979-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143121602","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":"Synthesis and characterization of ester-free poly(trimethylene carbonate) bearing long-alkyl moieties and its degradation","authors":"Ayun Erwina Arifianti, Takamasa Matsumoto, Nalinthip Chanthaset, Hiroharu Ajiro","doi":"10.1038/s41428-024-00984-9","DOIUrl":"10.1038/s41428-024-00984-9","url":null,"abstract":"Compared with ester derivatives, ester-free poly(trimethylene carbonate) (PTMC) derivatives have attracted increased interest because they do not create any acidic compounds after decomposition. Inspired by the chemical structure of poly(α-olefin)s or branched polyethylene (PE), various lengths of alkyl chains, such as -C8H17, -C12H25, -C16H33, -C18H37, and -C20H41, were introduced into trimethylene carbonate (TMC) with ester-free structures to improve the physical properties of PTMC, which can be labeled with trimethylolethane. These monomers were polymerized, and their thermal properties, hydrophobicity, and degradation behavior were investigated. When the length of the alkyl chain was longer than -C16H33, the polymer solidified with higher melting points than at room temperature. The poly(trimethylene carbonate) (PTMC) derivative with a -C18H37 group at the side chain was used for the hydrolysis test both in organic and aqueous solvents, resulting in 91% degradation after 9 weeks in a mixture of THF-d8, D2O, and NaOHaq at room temperature, whereas only 11% degradation was observed in NaODaq. after 9 weeks, suggesting that the hydrophobic long alkyl chains at the side chains influenced their hydrophobic nature and degradation manner. Various lengths of alkyl chains, like -C8H17 to -C20H41, were introduced into trimethylene carbonate (TMC) to enhance the physical properties of ester-free poly(trimethylene carbonate) (PTMC). The resulting polymers were studied for their thermal properties, hydrophobicity, and degradation behavior. Solidified PTMC was achieved with alkyl chains longer than -C16H33 and had melting points above room temperature. PTMC derivative with a -C18H37 group side chain showed 91% and 11% degradation after 9 weeks under organic and aqueous condition, respectively, suggesting that the long alkyl chains influenced its hydrophobic nature and degradation behavior.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 3","pages":"279-290"},"PeriodicalIF":2.3,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143555253","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":"Research on the preparation and performance of acrylic acid/methyl acrylate-modified starch catalyzed by an HRP binary initiation system","authors":"Wenda Wang, Qiang Wang, Ping Wang","doi":"10.1038/s41428-024-00982-x","DOIUrl":"10.1038/s41428-024-00982-x","url":null,"abstract":"Acrylic acid (AA)/methyl acrylate (MA)-modified starch was prepared via a catalytic process involving horseradish peroxidase (HRP)/acetylacetone (ACAC) as an initiation system. The structural analysis results demonstrated that the grafting of AA and MA onto starch was successful. Furthermore, the impact of the grafting reaction conditions on the grafting effect and the characteristics of the resulting grafted products were also examined. The results demonstrated that AA and MA were successfully grafted onto starch. The optimal conditions for starch grafting with AA/MA were identified as a reaction time of 4 h, an HRP enzyme concentration of 12 U/mL, a total monomer/starch ratio of 4:6, and a molar ratio of AA/MA feeding of 3:7. The viscosity and viscoelasticity of the modified starch slurry increased, and the film-forming property was enhanced. Compared with the original starch film, the modified film markedly increased the flexibility and tensile strength. Furthermore, an increased acrylic acid content maintained the original hydrophilicity of the modified starch film. The horseradish peroxidase (HRP)/acetone peroxide (ACAC) binary system serves as an initiator to stimulate the generation of free radicals from starch, acrylic acid (AA), and methyl acrylate (MA). Simultaneously, while AA and MA undergo self-polymerization and copolymerization, they also get grafted onto starch chains through self-polymerization and alternating copolymerization. A substantial number of branched small-molecule chains are uniformly grafted onto the primary chain of starch with a low molecular weight.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 2","pages":"189-201"},"PeriodicalIF":2.3,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143121638","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":"Anionic polymerization driven by flow microchemistry","authors":"Aiichiro Nagaki, Yosuke Ashikari","doi":"10.1038/s41428-024-00972-z","DOIUrl":"10.1038/s41428-024-00972-z","url":null,"abstract":"This focus review describes advancements in anionic polymerization achieved using flow microreactors. Anionic polymerization using traditional flask chemistry often requires extremely low temperatures and complex setups; thus, it is unsuitable for large-scale production. Flow microreactors, with features such as precise temperature control, rapid mixing, and precise time control, can overcome these limitations. Using these microreactors, otherwise impossible polymer synthesis reactions can occur, and a controlled molecular weight distribution and high reaction selectivity is attained. Due to the ability to perform reactions at high temperatures without excessive cooling, this method is environmentally friendly and cost-effective. Additionally, precise time control allows the use of highly unstable polymer chain ends and functionalized alkyllithiums for further reactions, facilitating the synthesis of heterotelechelic polymers. Similar to those in laboratory-scale experiments, the continuous operation of the flow microreactors can be used to scale up the reaction under conditions, demonstrating their potential for industrial applications. This focus review highlights the significant contributions of flow microreactors to polymer production and facilitates future advancements in high-speed, environmentally benign polymer synthesis. Our recent studies on the anionic polymerization achieved using flow microreactors are reviewed. Using flow microreactors, with features such as precise temperature control, rapid mixing, and precise time control, otherwise impossible polymer synthesis reactions can occur. Some typical examples synthesizing polymers with reactive functional groups and heterotelechelic polymers are described. This review also highlights the in-line analyses of the polymer living end, helping a deeper insights of the reaction and its conditions. The continuous operation of the flow microreactors demonstrated their potential for industrial applications.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 2","pages":"143-148"},"PeriodicalIF":2.3,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143121607","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":"A combined study on intermolecular interactions between polystyrene and d-limonene utilizing light-scattering experiments and computational simulations","authors":"Takuto Sato, Naoki Chikuba, Daichi Ida, Masashi Osa","doi":"10.1038/s41428-024-00987-6","DOIUrl":"10.1038/s41428-024-00987-6","url":null,"abstract":"To quantitatively evaluate the solvent quality of d-limonene for polystyrene, light-scattering experiments were performed on polystyrene in d-limonene. Molecular-level information on the intermolecular interactions between the repeat unit of polystyrene and d-limonene was obtained by means of computational simulations. From the light-scattering experiments, the mean-square radius of gyration 〈S2〉 values for atactic polystyrene (a-PS) with weight-average molecular weights ranging from 3.73 × 104 to 2.87 × 106 in d-limonene at 25.0 °C were determined to be between those in toluene, a good solvent, and those in cyclohexane, a poor solvent. Moreover, the second virial coefficient A2 values of a-PS in d-limonene were smaller than half of those in toluene. The 〈S2〉 and A2 values were analyzed according to the helical wormlike chain model, and the binary-cluster integral β, representing the magnitude of the excluded volume between constituent segments of a-PS, was found to exhibit an intermediate value between those in toluene and cyclohexane, confirming that d-limonene is a medium solvent for a-PS. The intermolecular interaction energy between cumene as a model compound representing the repeat unit of polystyrene and d-limonene, which was obtained from the computational simulations, supported the estimated solvent quality for polystyrene. The intermolecular interactions between polystyrene (PS) and d-limonene were comprehensively studied utilizing both light-scattering experiments and computational simulations. From analyses of the mean-square radius of gyration 〈S2〉 and second virial coefficient A2 for PS in d-limonene determined by the light-scattering experiments, d-limonene was confirmed as a medium solvent with intermediate solvent quality between good solvents like toluene and poor solvents like cyclohexane for PS. The intermolecular interaction energy between repeat unit of PS and d-limonene, which was obtained from the computational simulations, supported the estimated solvent quality for PS.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 2","pages":"171-179"},"PeriodicalIF":2.3,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143121609","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":"Simple machine learning model for the glass transition temperatures of hydrated polymers","authors":"Shin-nosuke Nishimura, Yuta Kashihara, Tomoyuki Koga","doi":"10.1038/s41428-024-00981-y","DOIUrl":"10.1038/s41428-024-00981-y","url":null,"abstract":"The glass transition temperature under dry conditions (Tg,dry) is an important factor for understanding the properties of polymeric materials; however, Tg,dry is often not a suitable factor for understanding the functions of biomaterials because these materials are used in water or are in contact with water. Therefore, the glass transition temperature under hydrated conditions (Tg,wet) is a crucial thermal property of polymers, particularly biomaterials. Traditional Tg,wet measurements require significant skill and are prone to error. To address this, we developed a machine learning (ML) model to predict Tg,wet from the polymer structures using a small dataset of 33 polymers. SMILES was used to generate Morgan fingerprints (MFPs) and SMILES-fragments (FLs), which serve as descriptors for the ML models. We used both random forest (RF) and ridge regression (RR) algorithms, and these algorithms were optimizing through grid search and cross-validation. The ML models using only chemical structure descriptors (MFP and FL) exhibited poor predictive performance and showed overfitting. However, when the values of Tg,dry were included as an explanatory variable, the RR model using MFP provided the best performance. These results highlight the importance of incorporating the data of Tg,dry to enhance the prediction of Tg,wet. Our model has the potential to facilitate the design of functional biomaterials. The glass transition temperature of the dry polymers (Tg,dry) is a useful parameter for predicting that of hydrated polymers (Tg,wet). By combining Tg,dry and chemical structures, simple machine learning models for Tg,wet can be constructed even with a small dataset.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 2","pages":"225-231"},"PeriodicalIF":2.3,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143121642","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":"Special issue: Rising Stars in Polymer Science 2024","authors":"Keiji Tanaka","doi":"10.1038/s41428-024-00959-w","DOIUrl":"10.1038/s41428-024-00959-w","url":null,"abstract":"","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"56 11","pages":"945-947"},"PeriodicalIF":2.3,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-00959-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142579803","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}