Polymer Journal最新文献

{"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}

{"title":"Stress relaxation and improved fracture toughness of metal bonding using flexible monolith sheets and an epoxy adhesive","authors":"Yoshiyuki Kamo, Akikazu Matsumoto","doi":"10.1038/s41428-024-00975-w","DOIUrl":"10.1038/s41428-024-00975-w","url":null,"abstract":"While epoxy resins exhibit excellent mechanical and insulating properties as well as excellent stability against heat and chemicals, epoxy adhesives also have drawbacks such as brittleness and stress concentration. Rubber-based materials are often added to epoxy adhesives to increase toughness, but they are sensitive to heat and moisture, limiting their effectiveness in harsh environments. In this study, we propose a new sheet-type adhesive consisting of a conventional liquid epoxy adhesive and an epoxy monolith sheet with internal continuous pores, using the advantageous properties of the flexibility and toughness of the epoxy monolith to avoid stress concentration. We evaluated the adhesion strength for metal bonding using the sheet-type epoxy adhesives via a lap-shear tensile adhesion test at various temperatures. The total destruction energy was also estimated via a tapered double cantilever beam test. Furthermore, a heat cycle adhesion test was conducted using two types of metallic materials with different coefficients of thermal expansion to elucidate the effect of the monolith sheet on the improvement of interfacial failure induced by stress concentration. We propose a new sheet-type adhesive consisting of a conventional liquid epoxy adhesive and an epoxy monolith sheet with internal continuous pores to avoid stress concentration. We evaluated the adhesion strength for metal bonding using sheet-type epoxy adhesives via lap-shear tensile adhesion tests at various temperatures. The tapered double cantilever beam test revealed that the combination of the epoxy adhesive and the monolith sheet effectively increased the total fracture energy. Furthermore, a heat cycle adhesion test was conducted using two types of metallic materials with different coefficients of thermal expansion to elucidate the effect of the monolith sheet on the improvement of interfacial failure induced by stress concentration.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 2","pages":"203-214"},"PeriodicalIF":2.3,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-00975-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143121600","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":"Deprotection of the tert-butyl ester of poly(n-butyl methacrylate-b-tert-butyl methacrylate) under flow conditions by heterogeneous catalysts leading to acidic diblock copolymers","authors":"Ryo Takabayashi, Stephan Feser, Hiroshi Yonehara, Mamoru Hyodo, Ilhyong Ryu, Takahide Fukuyama","doi":"10.1038/s41428-024-00978-7","DOIUrl":"10.1038/s41428-024-00978-7","url":null,"abstract":"The selective deprotection of tertiary-butyl (tert-Bu) esters in diblock copolymers of polyesters was studied via heterogeneous acid catalysts and flow reactors. Diblock copolymers composed of n-butyl methacrylate (nBMA) as the 1st block and tert-butyl methacrylate (tBMA) as the 2nd block were prepared by group transfer polymerization (GTP) using diisobutyl ketone (DIBK) as the solvent. The selective deprotection of the tert-Bu ester in the poly(nBMA-b-tBMA) under flow conditions was examined. The results show that the selective deprotection of the tert-Bu ester was achieved successfully via an acidic macroreticular polymeric catalyst, Amberlyst 35DRY, packed in a flow reactor. The deprotection process required 15 min of residence at 180 °C to yield acidic poly(nBMA-b-methacrylic acid) with a polydispersity index (Ð) value as low as 1.28. The durability of the catalyst was also examined during a continuous process for 1500 min by an HPLC pump. Selective deprotection of tertiary-butyl (tert-Bu) ester in poly(n-butyl methacrylate-b-tert-butyl methacrylate) was studied via heterogeneous acid catalysts and flow reactors. We found that selective deprotection of tert-Bu ester was achieved successfully using an acidic macroreticular polymeric catalyst, Amberlyst 35DRY, packed in a flow reactor. The deprotection process required 15 min of residence time at 180 °C to give an acidic poly(n-butyl methacrylate-b-methacrylic acid) with a small polydispersity index (Ð) value such as 1.28.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 2","pages":"215-224"},"PeriodicalIF":2.3,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143110220","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":"Rational design of dual Chemo- and Thermo-responsive phase separation of Poly(4-hydroxystyrene) in non-aqueous media","authors":"Kota Hashimoto, Natsuki Inaba, Keitaro Matsuoka, Kazuki Sada","doi":"10.1038/s41428-024-00968-9","DOIUrl":"10.1038/s41428-024-00968-9","url":null,"abstract":"Dual stimuli-responsiveness in non-aqueous media could allow various molecular designs using a system that is not compatible with aqueous media. However, the difficulty in controlling the desolvation of the polymer chains in non-aqueous media for lower critical solution temperature (LCST)-type phase separation at ambient temperature has hindered the attainment of dual stimuli-responsiveness based on chemical stimuli. In this study, we rationally designed dual chemo- and thermo-responsive phase separations of poly(4-hydroxystyrene) in non-aqueous media. The LCST-type thermo-responsiveness of poly(4-hydroxystyrene) in 1,4-dioxane/toluene was considerably altered by the addition of small amounts of hydrogen-bonding molecules as chemical stimuli. Secondary amines or molecules containing two hydrogen-bonding functional groups formed stronger hydrogen bonds with the polymer chains than 1,4-dioxane, which altered the solvation state and induced the UCST-type thermo-responsiveness or insolubility of PHS. This dual stimuli-responsive system could serve as a chemical sensor to detect the presence of acids. Dual chemo- and thermo-responsive phase separations of poly(4-hydroxystyrene) in non-aqueous media were demonstrated. The addition of small amounts of hydrogen-bonding molecules as chemical stimuli caused a considerable change of LCST-type thermo-responsiveness of poly(4-hydroxystyrene) in 1,4-dioxane/toluene. Secondary amines or molecules containing two hydrogen-bonding functional groups could cross-link the polymer chains through the hydrogen bonds, which altered the solvation state and induced the UCST-type thermo-responsiveness or insolubility of the polymer. This dual stimuli-responsive system worked as a chemical sensor to detect the presence of acids.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 2","pages":"181-188"},"PeriodicalIF":2.3,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143121557","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":"Nonlinear stress relaxation and failure of time‒strain separability of aqueous poly(ethylene oxide)/silica nanoparticle mixtures","authors":"Saki Kusakabe, Takuya Katashima, Ichiro Sakuma, Yuki Akagi","doi":"10.1038/s41428-024-00974-x","DOIUrl":"10.1038/s41428-024-00974-x","url":null,"abstract":"The stress relaxation test is an effective and facile method for clarifying the nonlinear rheological behavior of soft materials. A thorough analysis of the stress relaxation behavior offers valuable insights into the molecular dynamics. However, the stress relaxation behavior and underlying molecular dynamics of polymer/particle mixtures remain poorly understood, despite their widespread industrial application. In this study, we systematically investigated the nonlinear stress relaxation behavior of a simple-structured poly(ethylene oxide) (PEO)/silica nanoparticle aqueous mixture. Time‒strain separability was observed at high polymer concentrations, with the stress relaxation attributable to the relaxation of the polymer matrix. At lower polymer concentrations, the time‒strain separability was no longer valid, and changes in absorbance over time suggested that stress relaxation originated from the relaxation of the aggregated structures. A transition from time‒strain separability to inseparability was observed when the estimated number of PEO molecules forming interparticle bridges was less than 1; this suggests that structural changes during shear loading occur only when new interparticle polymer bridges are formed, leading to the development of clustered structures. These results provide a basic understanding of the relationship between deformation and relaxation, which is crucial for systematically understanding the nonlinear rheology of polymeric materials. Normalized relaxation time as a function of the estimated number of interparticle polymer bridges (nbridge). Images show the molecular dynamics pertaining to nbridge < 1 and 1 < nbridge.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 2","pages":"163-170"},"PeriodicalIF":2.3,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143121608","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":"Modification of fiber-reinforced composites using polymer blends as matrices","authors":"Takayuki Hirai","doi":"10.1038/s41428-024-00977-8","DOIUrl":"10.1038/s41428-024-00977-8","url":null,"abstract":"Composite materials are widely used in many industrial products because they combine the properties of organic and inorganic materials. This review focuses on the property modification of composite materials where polymer blends are used as matrices to obtain functional composites. Polymer blends can be fabricated via the physical process of melt mixing; thus, they have good scalability. However, poor material design criteria compared with those of polymer synthesis are critical defects in polymer blending. To address this problem, we focused on the multiscale phase separation in polymer blends. Polymer blends can be divided into three categories according to their phase morphology: immiscible, miscible, and reactive. They exhibit characteristic behaviors that depend on their morphology. We propose a novel material design concept to combine polymers with different phase morphologies to obtain a combination of modification mechanisms. To provide specific examples, two previous studies on the modification of carbon- and glass-fiber-reinforced plastics were summarized. One study involves improving the hygrothermal resistance of carbon-fiber-reinforced polyamide by incorporating both miscible and immiscible components into the polyamide. The other study involves fabricating transparent glass-fiber-reinforced polyamides by investigating miscible and reactive blends. Our recent study on the property modification of composite materials where polymer blends are used as matrices were summarized. Polymer blends have good scalability; however, poor material design criteria is a critical defect in polymer blending. To address this problem, we focused on the multiscale phase separation in polymer blends. We propose a novel material design concept to combine polymers with different phase morphologies to obtain a combination of modification mechanisms, and hygrothermal resistant CFRP and transparent GFRP using polymer blends as matrix were obtained.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 1","pages":"79-86"},"PeriodicalIF":2.3,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142925796","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":"Peptide-mediated gene and protein delivery systems to plant mitochondria for modifying mitochondrial functions","authors":"Naoya Abe, Keiji Numata","doi":"10.1038/s41428-024-00973-y","DOIUrl":"10.1038/s41428-024-00973-y","url":null,"abstract":"Plant mitochondria are essential for energy production and male sterility. The genetic transformation of plant mitochondria has attracted attention due to its potential to improve the mitochondrial function and agricultural productivity of energy crops. However, mitochondrial genome editing has been challenging because the delivery of the macromolecules needed for genome engineering to mitochondria has not been established until now. In addition, the genome editing efficiency in mitochondria needs to be improved as much as possible due to the lack of a selection marker for mitochondria. To achieve mitochondrial modification, the proteins and/or DNA/RNA needed for genome editing should be delivered to mitochondria precisely and efficiently. Peptides have been utilized to improve delivery efficiency to plant mitochondria. Thus, we herein review advances in delivery technologies related to plant mitochondrial genome engineering using various functional peptides. There are many barriers to gene and protein delivery to plant mitochondria, such as cell walls, cell membranes, and cytosolic localization. Functional peptides have been used to overcome these barriers. Peptides have a characteristic function depending on their sequence and high-order structure. The cytotoxicity of these peptides is also low. Therefore, functional peptides have attracted attention for their ability to improve gene and protein delivery efficiency to plant mitochondria.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 1","pages":"57-68"},"PeriodicalIF":2.3,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-00973-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142925794","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":"Development of polymer syntheses using diazocarbonyl compounds as monomers","authors":"Eiji Ihara","doi":"10.1038/s41428-024-00954-1","DOIUrl":"10.1038/s41428-024-00954-1","url":null,"abstract":"Recent results from the author’s research group on the development of polymer syntheses using diazocarbonyl compounds as monomers are described. A series of new Pd-based initiating systems for C1 polymerization of diazoacetate have been developed, each of which possesses characteristic initiating ability with respect to high-molecular-weight polymer synthesis, tacticity control, and chain end functionalization. The use of functional ester substituents has led to polymers with unique properties and functionalities in comparison to their vinyl polymer counterparts [poly(alkyl acrylate)] with the same ester substituent. Polycondensations using bis(diazocarbonyl) compounds as monomers are also described. By utilizing a variety of reactivities of a diazocarbonyl group, a series of three-, two-, and single-component polycondensations have been realized, affording new polymers whose chemical structures cannot be attained by any existing method for polymer syntheses. Polymer syntheses utilizing diazocarbonyl compounds as monomers are described. Pd-based initiators active for the C1 polymerization of diazoacetates have been developed; the presence of η3-type anionic ligand on the Pd center has been proved to be essential for the initiator to be highly active for the polymerization. Pd complexes bearing naphthoquinone or its derivatives as a ligand were effective for the initiator generation in conjunction with NaBPh4. By using a series of bis(diazocarbonyl) compounds as monomers, three-, two-, and single-component polycondensations have been newly developed, affording unprecedented polymer structures.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 1","pages":"1-23"},"PeriodicalIF":2.3,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142925786","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}