Polymer Journal最新文献_第4页

Synthesis and two-dimensional ordering of asymmetrically polymer–brush–decorated cellulose nanocrystals 非对称聚合物刷饰纤维素纳米晶体的合成与二维有序

IF 2.3 4区化学

Polymer Journal Pub Date : 2024-12-05 DOI: 10.1038/s41428-024-00994-7

Yuji Kinose, Seitaro Fujimoto, Keita Sakakibara, Yoshinobu Tsujii

{"title":"Synthesis and two-dimensional ordering of asymmetrically polymer–brush–decorated cellulose nanocrystals","authors":"Yuji Kinose, Seitaro Fujimoto, Keita Sakakibara, Yoshinobu Tsujii","doi":"10.1038/s41428-024-00994-7","DOIUrl":"10.1038/s41428-024-00994-7","url":null,"abstract":"Rod-shaped cellulose nanocrystals (CNCs) are typically obtained by hydrolyzing cellulose nanofibers bearing an formyl group at their reducing end. In this study, we prepare CNCs bearing densely grafted polymer brushes of different molecular weights (asymmetrically polymer-brush–decorated CNCs; aPB-CNCs). aPB-CNCs exhibit good dispersion in organic solvents and form a monolayer at the air/water interface. The compression of this monolayer induces a phase transition of a long polymer brush at the reducing end and a change in the orientation of the CNC core due to repulsive interactions. A CNC is identified as a key intermediate, possessing dormant moieties for reversible addition–fragmentation polymerization and atom transfer radical polymerization at the reducing end and other surfaces, respectively (bifunctional dormant CNC). This functional CNC facilitates the polymerization of a wide range of monomers and enables the synthesis of aPB-CNCs with diverse chemical properties. The developed synthetic route not only provides a basis for exploring the ordered structure of nanoparticles but is also useful for modifying the reducing ends of CNCs. Cellulose nanocrystals (CNCs) bearing densely grafted polymer brushes of different molecular weights (asymmetrically polymer-brush–decorated CNCs; aPB-CNCs) were synthesized via a CNC intermediate possessing two types of dormant moieties for controlled radical polymerization at the reducing end and other surfaces, respectively. The aPB-CNCs exhibited good dispersion in organic solvents and form a monolayer at the air/water interface. The compression of this monolayer induced a phase transition of a long polymer brush at the reducing end and a change in the orientation of the CNC core due to repulsive interactions.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 3","pages":"269-277"},"PeriodicalIF":2.3,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-00994-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143555254","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}

引用次数: 0

Crosslink inhomogeneity in epoxy resins cured with a phenolic hardener under organophosphine catalysts revealed by small-angle X-ray scattering 用小角x射线散射研究了酚醛固化剂固化环氧树脂在有机膦催化剂下的交联不均匀性

IF 2.3 4区化学

Polymer Journal Pub Date : 2024-12-04 DOI: 10.1038/s41428-024-00993-8

Takeshi Kakara, Atsushi Izumi, Yasuyuki Shudo, Atsuomi Shundo, Keiji Tanaka

{"title":"Crosslink inhomogeneity in epoxy resins cured with a phenolic hardener under organophosphine catalysts revealed by small-angle X-ray scattering","authors":"Takeshi Kakara, Atsushi Izumi, Yasuyuki Shudo, Atsuomi Shundo, Keiji Tanaka","doi":"10.1038/s41428-024-00993-8","DOIUrl":"10.1038/s41428-024-00993-8","url":null,"abstract":"In this study, the crosslink inhomogeneities in two types of epoxy resins cured with a phenolic hardener under organophosphine catalysts were successfully clarified by small-angle X-ray scattering (SAXS) using a solvent-swelling technique. Herein, triphenylphosphine (TPP) and tetraphenylphosphonium tetra-p-tolylborate (TPPTTB) were investigated as the curing catalysts. The SAXS profiles in a fully tetrahydrofuran (THF)-swollen state clearly revealed a difference between the two types of resins. The profiles at the early, middle, and late stages of gelation were effectively explained by a sum of structural functions representing the crosslinking inhomogeneity and concentration fluctuations of the polymer chains. Furthermore, the change in the profiles indicated that the characteristic size of inhomogeneity was associated with the size of the minor, low-crosslink density region. The correlation lengths of the mesh size decreased to 1 nm for both resins. These results confirmed the formation of a well-developed crosslinked network structure. Moreover, the correlation lengths of the crosslink inhomogeneity at the late stage of gelation were 1 and 5 nm for the TPP- and TPPTTB-cured resins, respectively. Thus, the phenolic-cured epoxy resins using an organophosphine catalyst system exhibited a THF-swellable, low crosslink density region due to inhomogeneity at the late stage of gelation. This rapid communication reports the first successful clarification of the difference in the crosslink inhomogeneity at the nanometer scale for two types of structurally identical epoxy resins cured with a phenolic hardener under organophosphine catalysts.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 4","pages":"377-383"},"PeriodicalIF":2.3,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-00993-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143787323","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}

引用次数: 0

Poisson’s ratio transition in strain crystallizing elastomer: from rubbery amorphous to semicrystalline 应变结晶弹性体的泊松比转变：从橡胶无定形到半结晶

IF 2.3 4区化学

Polymer Journal Pub Date : 2024-12-04 DOI: 10.1038/s41428-024-00998-3

Takuho Naraoka, Ruito Tanaka, Hideaki Takagi, Katsuhiko Tsunoda, Thanh-Tam Mai, Shinichi Sakurai, Kenji Urayama

{"title":"Poisson’s ratio transition in strain crystallizing elastomer: from rubbery amorphous to semicrystalline","authors":"Takuho Naraoka, Ruito Tanaka, Hideaki Takagi, Katsuhiko Tsunoda, Thanh-Tam Mai, Shinichi Sakurai, Kenji Urayama","doi":"10.1038/s41428-024-00998-3","DOIUrl":"10.1038/s41428-024-00998-3","url":null,"abstract":"The Poisson’s ratio (μ) of natural rubber (NR) undergoing strain-induced crystallization (SIC) during uniaxial stretching was investigated as a function of the applied stretch ( $${lambda }_{{||}}$$ ) over a broad $${lambda }_{{||}}$$ range, encompassing the SIC onset stretch ( $${{lambda }_{{||}}}^{* }$$ ≈ 4.1). Below $${{lambda }_{{||}}}^{* }$$ , μ remains near 1/2, indicating the incompressible behavior of NR in its fully rubbery amorphous state. However, once $${lambda }_{{||}}$$ exceeds $${{lambda }_{{||}}}^{* }$$ , μ decreases as the degree of crystallinity (χc) increases. As $${lambda }_{{||}}$$ increases from $${{lambda }_{{||}}}^{* }$$ to fracture stretch ( $${lambda }_{{||}}$$ ≈ 7.1), χc increases to 18%, and μ gradually decreases to 0.33. This reduction in μ reflects the transformation of the NR matrix from a rubbery amorphous state to a semicrystalline state. In fact, the true stress (force per cross-sectional area in the deformed state) at the fracture point, obtained via actual lateral contraction, is approximately 85% of that estimated under the assumption μ = 1/2. These findings provide a critical foundation for accurately modeling the mechanical behavior of strain-crystallizing elastomers. The Poisson''s ratio (μ) of natural rubber undergoing strain-induced crystallization was studied across a broad stretch range. Below the crystallization onset stretch ( $${lambda }_{{||}}$$ * ≈ 4.1), μ remains near 0.5, indicating incompressibility. Beyond $${lambda }_{{||}}$$ *, μ decreases with increasing crystallinity, reaching 0.33 at fracture ( $${lambda }_{{||}}$$ ≈ 7.1), as the matrix transforms from amorphous to semicrystalline. The true stress at fracture, accounting for lateral contraction, is approximately 85% of the estimated value assuming μ = 0.5. These insights are vital for modeling the mechanical behavior of strain-crystallizing elastomers.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 4","pages":"477-482"},"PeriodicalIF":2.3,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-00998-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143787386","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}

引用次数: 0

Review of bioderived and biodegradable polymers/block-copolymers and their biomedical and electronic applications 生物衍生和可生物降解聚合物/嵌段共聚物及其生物医学和电子应用综述

IF 2.3 4区化学

Polymer Journal Pub Date : 2024-12-03 DOI: 10.1038/s41428-024-00980-z

Ping-Jui Yu, Yan-Cheng Lin, Wen-Chang Chen

{"title":"Review of bioderived and biodegradable polymers/block-copolymers and their biomedical and electronic applications","authors":"Ping-Jui Yu, Yan-Cheng Lin, Wen-Chang Chen","doi":"10.1038/s41428-024-00980-z","DOIUrl":"10.1038/s41428-024-00980-z","url":null,"abstract":"The growing awareness of eco-friendly and high-value materials has attracted many researchers to green chemistry. With versatile advantages, biodegradability is the paramount property for waste disposal or recycling, and it can determine whether a product is environmentally sustainable. Moreover, bioderived materials are crucial because the reprocessed products are difficult to handle after recycling. Therefore, biodegradable and bioderived materials can address increasing environmental issues via recycling approaches and reprocessing products. Combining these sustainable concepts, block copolymers (BCPs) with self-assembling characteristics have been extensively investigated for use in biobased materials, green processing, and recyclable electronic applications. This mini-review introduces the design and syntheses of the starting biobased monomers, prepolymers, and block copolymers. Then, their degradability and recyclability are evaluated. Due to their significant potential, biobased and biodegradable BCPs hold great promise in biomedical and optoelectronic applications. Bioderived materials are value-added by recycling excessive residues to gain a new life for themselves. Biodegradable materials can address increasing environmental issues via recycling approaches and reprocessing products. Concerning these attractive advantages, in the first part of this review, commodity polymers from biosources and their recycling and biodegradable pathways are described. The second part summarizes the recent advances of bioderived and biodegradable block copolymers in biomedical and electronic applications, including drug carriers, field-effect transistors, and nonvolatile memory. This review sheds light on the bright perspective of bioderived and biodegradable polymers.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 3","pages":"233-247"},"PeriodicalIF":2.3,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143555238","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}

引用次数: 0

Off-stoichiometry effect on the physical properties of epoxy resins 非化学计量对环氧树脂物理性质的影响

IF 2.3 4区化学

Polymer Journal Pub Date : 2024-11-29 DOI: 10.1038/s41428-024-00983-w

Satoru Yamamoto, Nguyen Thao Phan, Kouki Kihara, Atsuomi Shundo, Keiji Tanaka

{"title":"Off-stoichiometry effect on the physical properties of epoxy resins","authors":"Satoru Yamamoto, Nguyen Thao Phan, Kouki Kihara, Atsuomi Shundo, Keiji Tanaka","doi":"10.1038/s41428-024-00983-w","DOIUrl":"10.1038/s41428-024-00983-w","url":null,"abstract":"Amines generally tend to segregate at the interface of the epoxy resins cured with amines. To gain better insight into the aggregation states and physical properties at the adhesive interface, we examined the cross-linking structure and physical properties of the cured epoxy resins with an off-stoichiometric ratio of epoxy and amine. As the excess amine increased, the amine not only remained as unreacted monomers or low-molecular-weight isolated chains within the cross-linking structure but also formed dangling chain ends, increasing heterogeneity in the cured epoxy resin. As a result, the cross-linking density and mass density decreased, along with a reduction in the glass transition temperature. On the other hand, Young’s modulus increased with the excess amount of amine. Wide-angle X-ray scattering experiments, in conjunction with molecular dynamics simulations, revealed that the excess amine suppressed the widening of the distance between phenyl groups during the curing reaction, suggesting that this could act as steric resistance during deformation. The cross-linking structure and physical properties of epoxy resins cured with amine under off-stoichiometric ratio conditions were examined. As the excess amine increased, some of the amine not only remained as unreacted monomers or low-molecular-weight isolated chains within the cross-linking structure, but also formed dangling chain ends. As a result, the cross-linking density and mass density decreased, as did the glass transition temperature. On the other hand, Young’s modulus increased with the excess amount of amine due to the suppression of the widening distance between phenyl groups.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 4","pages":"357-366"},"PeriodicalIF":2.3,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-00983-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143787391","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}

引用次数: 0

Salt concentration dependency of the hydrated swollen structure of cholinephosphate-type polyzwitterion brushes 磷酸胆碱型多两性刷水合膨胀结构的盐浓度依赖性

IF 2.3 4区化学

Polymer Journal Pub Date : 2024-11-28 DOI: 10.1038/s41428-024-00991-w

Takumi Komiya, Norifumi L. Yamada, Motoyasu Kobayashi

{"title":"Salt concentration dependency of the hydrated swollen structure of cholinephosphate-type polyzwitterion brushes","authors":"Takumi Komiya, Norifumi L. Yamada, Motoyasu Kobayashi","doi":"10.1038/s41428-024-00991-w","DOIUrl":"10.1038/s41428-024-00991-w","url":null,"abstract":"The swollen thicknesses of zwitterionic polymer brushes with phosphorylcholine (PC), cholinephosphate (CP), sulfobetaine, and carboxybetaine groups were measured in aqueous sodium chloride (NaCl) or calcium chloride (CaCl2) solutions via force curve measurements by scanning probe microscopy (SPM) and neutron reflectivity measurements. PC and CP have different charge positions in betaine units consisting of ammonium and phosphate. The PC-type polymer brush did not distinctly reduce the swollen thickness in either the NaCl or CaCl2 solution, even at 1000 mM. However, the swollen thickness of the CP-type polymer brushes was clearly reduced in the aqueous CaCl2 solution. Unlike the phosphate of PC, which is located inside the betaine unit, the phosphate of CP tends to form insoluble calcium phosphate, resulting in the collapse of the brush structure. The effect of calcium ion on the swelling structure of polymer brushes bearing phosphorylcholine (PC) and cholinephosphate (CP) groups in aqueous solution were investigated by scanning probe microscopy and neutron reflectivity measurements. The CP-type polymer brushes formed collapsed structure in the aqueous CaCl2 solution because the phosphate of CP, which is located outside the betaine unit, strongly interacts with calcium ions to form insoluble calcium phosphate. In contrast, no significant change was observed in the swollen thickness of the PC-type polymer brush in the aqueous CaCl2 solution.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 3","pages":"291-301"},"PeriodicalIF":2.3,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143555237","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}

引用次数: 0

Brownian simulations for fracture of star polymer phantom networks 星形聚合物幻影网络断裂的布朗模拟

IF 2.3 4区化学

Polymer Journal Pub Date : 2024-11-28 DOI: 10.1038/s41428-024-00992-9

Yuichi Masubuchi, Yusuke Koide, Takato Ishida, Takashi Uneyama

{"title":"Brownian simulations for fracture of star polymer phantom networks","authors":"Yuichi Masubuchi, Yusuke Koide, Takato Ishida, Takashi Uneyama","doi":"10.1038/s41428-024-00992-9","DOIUrl":"10.1038/s41428-024-00992-9","url":null,"abstract":"According to a recent simulation study [Masubuchi et al., Macromolecules, 56, 9359 (2023)], the cycle rank plays a significant role in determining the fracture characteristics of network polymers. However, the previous studies considered only energy-minimized networks without including the effects of thermal agitation. To address this gap, this study conducted Brownian dynamics simulations at various stretch rates. The results showed that even with Brownian motion, the strain and stress at break obtained for different node functionalities and conversion ratios exhibited master curves when plotted versus the cycle rank. These master curves depend on the strain rate, indicating that the strain and stress at break decrease with decreasing strain rate. The curves are qualitatively similar to those observed in energy-minimized simulations, even though the competition among Brownian motion, elongation, and bond scission affects the fracture process. This study examined the fracture of polymer networks via Brownian simulations with various strain rates. The networks were created from star polymers with different branching degrees and conversion ratios. The results showed that strain and stress at break, plotted against cycle rank, form master curves dependent on strain rate; the fracture characteristics decrease with decreasing strain rate. Despite the interplay of Brownian motion, elongation, and bond scission, the cycle rank dependence is qualitatively similar to that reported previously for energy-minimized networks.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 4","pages":"483-489"},"PeriodicalIF":2.3,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-00992-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143787388","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}

引用次数: 0

Control of surface structure and properties by side chain effects of polymers 聚合物的副链效应对表面结构和性能的控制

IF 2.3 4区化学

Polymer Journal Pub Date : 2024-11-28 DOI: 10.1038/s41428-024-00976-9

Takuya Matsumoto

{"title":"Control of surface structure and properties by side chain effects of polymers","authors":"Takuya Matsumoto","doi":"10.1038/s41428-024-00976-9","DOIUrl":"10.1038/s41428-024-00976-9","url":null,"abstract":"Polymer surfaces and interfaces have received much attention in industrial fields because of their functional properties, including appearance, surface protection, reflectivity, anti-fouling, water-repellency, anti-fogging, anti-icing, adhesion, and gas permeability/barrier characteristics. In addition, because polymer surfaces have notably different properties and dynamic behaviors from bulk materials, many academic researchers have been interested in and contributed to the research on polymer surfaces and interfaces in recent decades. The properties and structure at the polymer surface and interface strongly depend on the chemical structure, conformation, and dynamics of the polymer chains. In this review, the impacts of the structure and dynamics of designed polymer side chains on the surface and interface properties and their mechanism are described. In particular, the control of the molecular conformation and dynamics leads to their characteristic surface and interface properties. Polymer surfaces have notably different properties and dynamic behaviors from bulk materials. The properties and structure at the polymer surface and interface strongly depend on the chemical structure, conformation and dynamics of the polymer chains. In this review, the impacts of the structure and dynamics of designed polymer side chains on the surface and interface properties and their mechanism are described. In particular, the control of the molecular conformation and dynamics leads to their characteristic surface and interface properties.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 3","pages":"249-258"},"PeriodicalIF":2.3,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-00976-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143555231","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}

引用次数: 0

Rates of increase and decrease for each block of poly(3-hydroxybutyrate)(P3HB)-b-poly(3-hydroxybutyrate-co-3-hydroxyvalerate)(P3HBV) and P3HBV-b-P3HB during biosynthesis by Ralstonia Eutropha 聚（3-羟基丁酸酯）(P3HB)-b-聚（3-羟基丁酸酯-co-3-羟基戊酸酯）（P3HBV）和P3HBV-b-P3HB在Ralstonia Eutropha生物合成过程中的增减率

IF 2.3 4区化学

Polymer Journal Pub Date : 2024-11-22 DOI: 10.1038/s41428-024-00989-4

Takahiko Nakaoki, Haruto Nakamura, Ren Yashita

{"title":"Rates of increase and decrease for each block of poly(3-hydroxybutyrate)(P3HB)-b-poly(3-hydroxybutyrate-co-3-hydroxyvalerate)(P3HBV) and P3HBV-b-P3HB during biosynthesis by Ralstonia Eutropha","authors":"Takahiko Nakaoki, Haruto Nakamura, Ren Yashita","doi":"10.1038/s41428-024-00989-4","DOIUrl":"10.1038/s41428-024-00989-4","url":null,"abstract":"The number-average molecular weights (Mns) of the first and second blocks of the poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (P3HBV)-b-poly(3-hydroxybutyrate) (P3HB) and P3HB-b-P3HBV block copolymers biosynthesized from Ralstonia eutropha were investigated. Pentanoic acid and glucose were used as carbon sources for the biosynthesis of the blocks of P3HBV and P3HB, respectively. The cultivation time for the first carbon source was fixed at 72 h, and that for the second carbon source was varied. The first and second blocks for P3HBV-b-P3HB and P3HB-b-P3HBV showed a decrease and increase in the Mn, respectively; this indicates that degradation and polymerization proceeded at the initial end of the first block and at the other end of the second block, respectively. In the biosynthesis of P3HBV-b-P3HB, the rates of decrease and increase in the Mn for the P3HBV and P3HB blocks were 9.0 × 103 and 2.9 × 104 g/(mol∙h), respectively. For P3HB-b-P3HBV, the rates of decrease and increase in the Mn were 2.6 × 103 and 2.0 × 103 g/(mol∙h) for P3HB and P3HBV, respectively. The number-average molecular weights (Mns) of the first and second blocks of the poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (P3HBV)-b-poly(3-hydroxybutyrate) (P3HB) and P3HB-b-P3HBV block copolymers biosynthesized from Ralstonia eutropha were investigated. The first and second blocks for both P3HBV-b-P3HB and P3HB-b-P3HBV showed a decrease and increase in the Mn, respectively; this indicates that degradation and polymerization proceeded at the initial end of the first block and at the other end of the second block, respectively.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 3","pages":"327-334"},"PeriodicalIF":2.3,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143555224","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}

引用次数: 0

Determination of the inhomogeneous deswelling of thermoresponsive poly(N-isopropyl methacrylamide) microgels by combining dynamic light scattering, high-speed atomic force microscopy, and electrophoresis 通过结合动态光散射、高速原子力显微镜和电泳测定热致伸缩性聚（N-异丙基甲基丙烯酰胺）微凝胶的不均匀消融性

IF 2.3 4区化学

Polymer Journal Pub Date : 2024-11-22 DOI: 10.1038/s41428-024-00988-5

Yuichiro Nishizawa, Takumi Inui, Takayuki Uchihashi, Daisuke Suzuki

{"title":"Determination of the inhomogeneous deswelling of thermoresponsive poly(N-isopropyl methacrylamide) microgels by combining dynamic light scattering, high-speed atomic force microscopy, and electrophoresis","authors":"Yuichiro Nishizawa, Takumi Inui, Takayuki Uchihashi, Daisuke Suzuki","doi":"10.1038/s41428-024-00988-5","DOIUrl":"10.1038/s41428-024-00988-5","url":null,"abstract":"Poly(N-isopropyl methacrylamide) microgels with a uniform size of approximately 250 nm in their swollen state were synthesized via aqueous free-radical precipitation polymerization. The electrodynamic phenomena of the microgels were analyzed quantitatively using Ohshima’s equation, which explains the electrodynamic phenomena of natural and artificial soft colloids. The thermoresponsive deswelling of the microgels with increasing temperature was investigated by combining electrophoresis with dynamic light scattering and high-speed atomic force microscopy. Based on the obtained results, a plausible mechanism for the structural change during microgel deswelling is proposed, in which the core dwells first and the outermost surface dwells last. The thermoresponsive behavior of the microgels, the surface properties, and the core region of the microgels were evaluated independently using light scattering, electrokinetic measurements, and high-speed atomic force microscopy. The heterogeneous deswelling behavior of the microgels was revealed by combining these techniques.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 4","pages":"419-426"},"PeriodicalIF":2.3,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-00988-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143787373","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}

引用次数: 0