Pub Date : 2025-11-21DOI: 10.1038/s41428-025-01111-y
Daisuke Tadokoro, Tomoya Imai
Synthetic polymers, such as plastics, are ubiquitous materials that are used in many applications. The sustainable use of plastics is becoming increasingly important given the emergent issues of environmental pollution by microplastics and the limited petroleum resources on Earth. One of the key strategies for the sustainable use of plastics is recycling. Enzymatic degradation is a promising technique for recycling plastic because this process requires neither energy nor harsh solvents, such as strong alkaline solutions and organic solvents. In this study, the enzymatic degradation of poly(ethylene terephthalate) (PET), a major plastic used in daily life, was investigated to improve the efficiency of enzymatic degradation by understanding the decay of the polymeric PET structure. The structural decay of an amorphous PET film induced by a PET-hydrolyzing enzyme (PETase) was analyzed using wide-angle X-ray diffraction (WAXD), small-angle X-ray scattering (SAXS), electron microscopy, and X-ray computed tomography (X-ray CT). Structural decay progressed from the surface of the film, and many nested pores (10–8–10–5 m) were found in the later stage of degradation, reflecting the structural difference between the surface and core of the material. The enzymatic degradation of amorphous poly (ethylene terephthalate)(PET) films by a PET-degrading enzyme was analyzed using SAXS, WAXD, SEM, X-CT, and weight-loss measurements. FAST-PETase induced the emergence of hierarchical boring structures ranging from 10⁻⁵ m to 10⁻⁸ m on PET, revealing that enzymatic degradation proceeds through interfacial interactions within the evolving porous surface layer. This study contributes essential knowledge toward the sustainable use of plastics, responding to growing global concerns over microplastic pollution and the scarcity of fossil resources.
{"title":"Structural decay of poly(ethylene terephthalate) by enzymatic degradation","authors":"Daisuke Tadokoro, Tomoya Imai","doi":"10.1038/s41428-025-01111-y","DOIUrl":"10.1038/s41428-025-01111-y","url":null,"abstract":"Synthetic polymers, such as plastics, are ubiquitous materials that are used in many applications. The sustainable use of plastics is becoming increasingly important given the emergent issues of environmental pollution by microplastics and the limited petroleum resources on Earth. One of the key strategies for the sustainable use of plastics is recycling. Enzymatic degradation is a promising technique for recycling plastic because this process requires neither energy nor harsh solvents, such as strong alkaline solutions and organic solvents. In this study, the enzymatic degradation of poly(ethylene terephthalate) (PET), a major plastic used in daily life, was investigated to improve the efficiency of enzymatic degradation by understanding the decay of the polymeric PET structure. The structural decay of an amorphous PET film induced by a PET-hydrolyzing enzyme (PETase) was analyzed using wide-angle X-ray diffraction (WAXD), small-angle X-ray scattering (SAXS), electron microscopy, and X-ray computed tomography (X-ray CT). Structural decay progressed from the surface of the film, and many nested pores (10–8–10–5 m) were found in the later stage of degradation, reflecting the structural difference between the surface and core of the material. The enzymatic degradation of amorphous poly (ethylene terephthalate)(PET) films by a PET-degrading enzyme was analyzed using SAXS, WAXD, SEM, X-CT, and weight-loss measurements. FAST-PETase induced the emergence of hierarchical boring structures ranging from 10⁻⁵ m to 10⁻⁸ m on PET, revealing that enzymatic degradation proceeds through interfacial interactions within the evolving porous surface layer. This study contributes essential knowledge toward the sustainable use of plastics, responding to growing global concerns over microplastic pollution and the scarcity of fossil resources.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"58 2","pages":"167-177"},"PeriodicalIF":2.7,"publicationDate":"2025-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.comhttps://www.nature.com/articles/s41428-025-01111-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146117003","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}
Nylon-6 exhibits several forms of crystal modification. The α form converts to the iodine complex when it is immersed in a highly concentrated KI/I2 solution. After deiodization in a hypo (sodium thiosulfate) solution, the iodine complex changes to the γ form. The phase transition mechanism from the α to the γ form through the iodine complex has remained a challenging issue because of the lack of established crystal structures. As previously reported (Polymer Journal, 2025), a quantitative analysis of 2D wide-angle X-ray and neutron diffraction data necessitated a revision of the crystal structure of the α form by incorporating up/down chain packing disorder. This paper reports that a similar up/down chain disorder is also present in the crystal lattices of the γ form and the iodine complexes. In both the α and γ forms, the crystal lattice is composed of stacked hydrogen-bonded sheet planes. The aforementioned up/down chain packing disorder can be expressed in terms of the stacking disorder of sheets or the disordered slippages of sheets along the a axis. Thus, the notion of stacking disorder of sheet planes allows for a systematic and logical interpretation of the transition behaviors among these crystalline forms of nylon-6. Analysis of wide-angle X-ray and neutron diffraction data has shown that the crystal structures of nylon-6 in both α and γ forms, as well as the iodine complex, are composed of statistically disordered arrangements of molecular chains. This composition can alternatively be described as the disordered slippages of sheet planes. The notion of stacking disorder within these sheets enables a logical interpretation of the transition mechanism among the three crystalline phases.
{"title":"Structural disorders in the α and γ forms and the iodine complex of nylon-6 and the mechanisms underlying their transitions","authors":"Kohji Tashiro, Kazuo Kurihara, Taro Tamada, Katsuhiro Kusaka, Terutoshi Sakakura","doi":"10.1038/s41428-025-01110-z","DOIUrl":"10.1038/s41428-025-01110-z","url":null,"abstract":"Nylon-6 exhibits several forms of crystal modification. The α form converts to the iodine complex when it is immersed in a highly concentrated KI/I2 solution. After deiodization in a hypo (sodium thiosulfate) solution, the iodine complex changes to the γ form. The phase transition mechanism from the α to the γ form through the iodine complex has remained a challenging issue because of the lack of established crystal structures. As previously reported (Polymer Journal, 2025), a quantitative analysis of 2D wide-angle X-ray and neutron diffraction data necessitated a revision of the crystal structure of the α form by incorporating up/down chain packing disorder. This paper reports that a similar up/down chain disorder is also present in the crystal lattices of the γ form and the iodine complexes. In both the α and γ forms, the crystal lattice is composed of stacked hydrogen-bonded sheet planes. The aforementioned up/down chain packing disorder can be expressed in terms of the stacking disorder of sheets or the disordered slippages of sheets along the a axis. Thus, the notion of stacking disorder of sheet planes allows for a systematic and logical interpretation of the transition behaviors among these crystalline forms of nylon-6. Analysis of wide-angle X-ray and neutron diffraction data has shown that the crystal structures of nylon-6 in both α and γ forms, as well as the iodine complex, are composed of statistically disordered arrangements of molecular chains. This composition can alternatively be described as the disordered slippages of sheet planes. The notion of stacking disorder within these sheets enables a logical interpretation of the transition mechanism among the three crystalline phases.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"58 2","pages":"137-148"},"PeriodicalIF":2.7,"publicationDate":"2025-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146117000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-11DOI: 10.1038/s41428-025-01114-9
Ruiqi Zhang, Yu-I Hsu, Hiroshi Uyama
Poly(butylene adipate-co-terephthalate) (PBAT) is an excellent candidate for porous material applications; however, its low melt strength presents challenges for producing foamed porous structures through conventional melt processing methods without modification. In this study, PBAT monoliths (PMs) were prepared via a solvent-based thermally induced phase separation (TIPS) method, which enables the formation of highly porous structures with tunable morphology. Furthermore, we noticed that compared with melt processing, the crystallization behavior of PM is unique to phase separation, strongly influencing the mechanical properties of the monoliths. After annealing, the elasticity of the PM significantly increased, and after compression to 70% strain, the plastic deformation decreased from approximately 43–12%. The effects of the annealing time and temperature on the PM performance were then further systematically investigated. This research contributes a template-free method for producing PBAT porous materials with tunable properties, potentially extending their application in fields such as catalysis, filtration, and tissue engineering. In this work, porous PBAT monoliths were fabricated via a solvent-based thermally induced phase separation (TIPS) method, and the pore morphology was tuned by adjusting the solvent ratio and polymer concentration. Furthermore, annealing treatment significantly enhanced the elasticity of the PBAT monoliths, reducing plastic deformation after 70% compression from 43 to 12%. Mechanistic analysis revealed that annealing improved defective crystals formed during phase separation, leading to enhanced structural integrity and mechanical performance.In this work, porous PBAT monoliths were fabricated via a solvent-based thermally induced phase separation (TIPS) method, and the pore morphology was tuned by adjusting the solvent ratio and polymer concentration. Furthermore, annealing treatment significantly enhanced the elasticity of the PBAT monoliths, reducing plastic deformation after 70% compression from 43% to 12%. Mechanistic analysis revealed that annealing improved defective crystals formed during phase separation, leading to enhanced structural integrity and mechanical performance.
{"title":"Fabrication of poly(butylene adipate-co-terephthalate) monoliths by thermally induced phase separation and the effect of the annealing process on mechanical properties","authors":"Ruiqi Zhang, Yu-I Hsu, Hiroshi Uyama","doi":"10.1038/s41428-025-01114-9","DOIUrl":"10.1038/s41428-025-01114-9","url":null,"abstract":"Poly(butylene adipate-co-terephthalate) (PBAT) is an excellent candidate for porous material applications; however, its low melt strength presents challenges for producing foamed porous structures through conventional melt processing methods without modification. In this study, PBAT monoliths (PMs) were prepared via a solvent-based thermally induced phase separation (TIPS) method, which enables the formation of highly porous structures with tunable morphology. Furthermore, we noticed that compared with melt processing, the crystallization behavior of PM is unique to phase separation, strongly influencing the mechanical properties of the monoliths. After annealing, the elasticity of the PM significantly increased, and after compression to 70% strain, the plastic deformation decreased from approximately 43–12%. The effects of the annealing time and temperature on the PM performance were then further systematically investigated. This research contributes a template-free method for producing PBAT porous materials with tunable properties, potentially extending their application in fields such as catalysis, filtration, and tissue engineering. In this work, porous PBAT monoliths were fabricated via a solvent-based thermally induced phase separation (TIPS) method, and the pore morphology was tuned by adjusting the solvent ratio and polymer concentration. Furthermore, annealing treatment significantly enhanced the elasticity of the PBAT monoliths, reducing plastic deformation after 70% compression from 43 to 12%. Mechanistic analysis revealed that annealing improved defective crystals formed during phase separation, leading to enhanced structural integrity and mechanical performance.In this work, porous PBAT monoliths were fabricated via a solvent-based thermally induced phase separation (TIPS) method, and the pore morphology was tuned by adjusting the solvent ratio and polymer concentration. Furthermore, annealing treatment significantly enhanced the elasticity of the PBAT monoliths, reducing plastic deformation after 70% compression from 43% to 12%. Mechanistic analysis revealed that annealing improved defective crystals formed during phase separation, leading to enhanced structural integrity and mechanical performance.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"58 2","pages":"149-158"},"PeriodicalIF":2.7,"publicationDate":"2025-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.comhttps://www.nature.com/articles/s41428-025-01114-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146117008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-07DOI: 10.1038/s41428-025-01112-x
Yasuhiro Matsuda, Hiroto Emi
The structure of interpolymer complex formed by poly(2-ethyl-2-oxazoline) and poly(methacrylic acid) was changed by controlling the hydrogen bonds between the polymer chains by changing the solvent pH or adding urea. The viscosity of solution containing the interpolymer complex drastically increased in solvent at pH~12, then decreased at pH~13. The infrared spectra of the interpolymer complexes formed in solvents at different pH indicated that the formation of hydrogen bonds among the polymer chains decreased with an increase of pH. These results were explained by a model in which the dimension of the interpolymer complex increased at pH~12, and the interpolymer complex dissociated into free polymer chains at pH~13. The hydrogen bonds of the interpolymer complex were also suppressed by adding urea to solvents. The viscosity of the solution containing the polymer-complex increased drastically when the urea concentration was over 6 M. The increase induced by the addition of urea can also be explained by the increase in the dimension of the interpolymer complex. The structure of interpolymer complex formed by poly(2-ethyl-2-oxazoline) and poly(methacrylic acid) by controlling the hydrogen bonds between the polymer chains by changing solvent pH or adding urea was investigated. The viscosity of solution containing the interpolymer complex was drastically increased in solvent with pH~12, then decreased at pH~13. This behavior can be explained by a model that the dimension of the complex was changed with a decrease of inter-polymer hydrogen bonds at high pH or urea concentration.
{"title":"Changes in the structure and viscosity of interpolymer complexes formed by poly(ethyl oxazoline) and poly(methacrylic acid) by controlling interpolymer hydrogen bonds","authors":"Yasuhiro Matsuda, Hiroto Emi","doi":"10.1038/s41428-025-01112-x","DOIUrl":"10.1038/s41428-025-01112-x","url":null,"abstract":"The structure of interpolymer complex formed by poly(2-ethyl-2-oxazoline) and poly(methacrylic acid) was changed by controlling the hydrogen bonds between the polymer chains by changing the solvent pH or adding urea. The viscosity of solution containing the interpolymer complex drastically increased in solvent at pH~12, then decreased at pH~13. The infrared spectra of the interpolymer complexes formed in solvents at different pH indicated that the formation of hydrogen bonds among the polymer chains decreased with an increase of pH. These results were explained by a model in which the dimension of the interpolymer complex increased at pH~12, and the interpolymer complex dissociated into free polymer chains at pH~13. The hydrogen bonds of the interpolymer complex were also suppressed by adding urea to solvents. The viscosity of the solution containing the polymer-complex increased drastically when the urea concentration was over 6 M. The increase induced by the addition of urea can also be explained by the increase in the dimension of the interpolymer complex. The structure of interpolymer complex formed by poly(2-ethyl-2-oxazoline) and poly(methacrylic acid) by controlling the hydrogen bonds between the polymer chains by changing solvent pH or adding urea was investigated. The viscosity of solution containing the interpolymer complex was drastically increased in solvent with pH~12, then decreased at pH~13. This behavior can be explained by a model that the dimension of the complex was changed with a decrease of inter-polymer hydrogen bonds at high pH or urea concentration.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"58 2","pages":"159-165"},"PeriodicalIF":2.7,"publicationDate":"2025-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.comhttps://www.nature.com/articles/s41428-025-01112-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146117005","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}
An artificial kidney is a medical device used in dialysis treatment for patients with renal failure. Owing to its prolonged contact with blood, artificial kidneys must have excellent antithrombogenic properties. An artificial kidney contains approximately 10,000 porous hollow fiber membranes, which remove water and uremic toxins from the blood through the principles of dialysis and filtration. It is well known that hollow fiber membranes made from polysulfone-based polymers (PSf) and polyvinylpyrrolidone (PVP) have high removal performance, accounting for 90% of the global market share. PVP, a hydrophilic polymer, contributes to the expression of antithrombogenic properties. However, complications due to insufficient antithrombogenic properties remain a challenge, and there has been strong demand for further improvements in antithrombogenic properties. We succeeded in commercializing PSf membrane artificial kidneys containing antithrombogenic polymers other than PVP for the first time by focusing on the mobility of adsorbed water. Furthermore, advanced analysis made it possible to design antithrombogenic polymers driven by computational science. This review discusses the design of antithrombogenic polymers based on the mobility of water and the commercialization of antithrombogenic artificial kidneys. In this review, we proposed a unique concept in which if the mobility of the adsorbed water around the proteins and the polymer is the same, protein adhesion will not occur, improving antithrombogenic properties. On the basis of the above concept, we have established the foundational technique for developing antithrombogenic materials and successfully achieved the world's first practical application of antithrombogenic PSf membrane artificial kidneys. The technique that enables polymer design led by computational science is applicable to various medical and diagnostic devices.
{"title":"Design of antithrombogenic polymers based on their interactions with water and commercialization of artificial kidneys","authors":"Yoshiyuki Ueno, Masaki Fujita, Hiroyuki Sugaya, Takeshi Baba, Masaru Nakada","doi":"10.1038/s41428-025-01045-5","DOIUrl":"10.1038/s41428-025-01045-5","url":null,"abstract":"An artificial kidney is a medical device used in dialysis treatment for patients with renal failure. Owing to its prolonged contact with blood, artificial kidneys must have excellent antithrombogenic properties. An artificial kidney contains approximately 10,000 porous hollow fiber membranes, which remove water and uremic toxins from the blood through the principles of dialysis and filtration. It is well known that hollow fiber membranes made from polysulfone-based polymers (PSf) and polyvinylpyrrolidone (PVP) have high removal performance, accounting for 90% of the global market share. PVP, a hydrophilic polymer, contributes to the expression of antithrombogenic properties. However, complications due to insufficient antithrombogenic properties remain a challenge, and there has been strong demand for further improvements in antithrombogenic properties. We succeeded in commercializing PSf membrane artificial kidneys containing antithrombogenic polymers other than PVP for the first time by focusing on the mobility of adsorbed water. Furthermore, advanced analysis made it possible to design antithrombogenic polymers driven by computational science. This review discusses the design of antithrombogenic polymers based on the mobility of water and the commercialization of antithrombogenic artificial kidneys. In this review, we proposed a unique concept in which if the mobility of the adsorbed water around the proteins and the polymer is the same, protein adhesion will not occur, improving antithrombogenic properties. On the basis of the above concept, we have established the foundational technique for developing antithrombogenic materials and successfully achieved the world's first practical application of antithrombogenic PSf membrane artificial kidneys. The technique that enables polymer design led by computational science is applicable to various medical and diagnostic devices.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"58 2","pages":"117-125"},"PeriodicalIF":2.7,"publicationDate":"2025-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146117006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-20DOI: 10.1038/s41428-025-01107-8
Masayuki Wakioka
Direct arylation polymerization (DArP) offers a streamlined alternative to Stille coupling for synthesizing π-conjugated donor–acceptor (DA) polymers by forming C–C bonds through formal C–H/C–X coupling, eliminating the need for toxic organotin reagents. Early DArP systems often failed to achieve both high molecular weight and low defect levels because of insufficient catalyst efficiency and selectivity. This Focus Review summarizes the development of highly efficient and selective palladium catalysts supported by the hemilabile phosphine P(2-MeOC6H4)3 (L1). L1 is used alone or with the coligands N,N,N′,N′‑tetramethylethylenediamine (TMEDA) or 2‑dicyclohexylphosphino‑2′,4′,6′‑triisopropylbiphenyl (XPhos). L1 maintains reactive mononuclear Pd species for efficient C–H activation; TMEDA suppresses side reactions such as homocoupling and branching; and XPhos facilitates the oxidative addition of less reactive C–X bonds. These ligand systems enable high-molecular-weight polymers (number-average molecular weight up to 347,700, yields up to 100%) with well-defined structures (cross-coupling selectivity as high as >99%) across a broad monomer scope. Devices based on these materials deliver up to 9.9% power conversion efficiency in organic photovoltaics and hole mobilities ≥0.3 cm2·V–1·s–1 in organic thin-film transistors, comparable to those from Stille coupling. These advances firmly position DArP as a practical, tin-free platform for the precise synthesis of high-performance π-conjugated DA polymers. This Review highlights our development of highly efficient and selective palladium catalysts for direct arylation polymerization (DArP). P(2-MeOC6H4)3 (L1) serves as a key supporting ligand that maintains reactive mononuclear Pd species. Coligands (TMEDA or XPhos) suppress side reactions and facilitate the activation of less reactive C–X bonds. Operating in polymer-solubilizing media (e.g., THF or toluene), these systems yield π-conjugated polymers with number-average molecular weights of up to 347,700 and cross-coupling selectivities of up to >99%; the resulting materials exhibit device-grade performance comparable to that of polymers prepared by conventional Stille coupling.
{"title":"Development of highly efficient and selective catalysts for direct arylation polymerization (DArP)","authors":"Masayuki Wakioka","doi":"10.1038/s41428-025-01107-8","DOIUrl":"10.1038/s41428-025-01107-8","url":null,"abstract":"Direct arylation polymerization (DArP) offers a streamlined alternative to Stille coupling for synthesizing π-conjugated donor–acceptor (DA) polymers by forming C–C bonds through formal C–H/C–X coupling, eliminating the need for toxic organotin reagents. Early DArP systems often failed to achieve both high molecular weight and low defect levels because of insufficient catalyst efficiency and selectivity. This Focus Review summarizes the development of highly efficient and selective palladium catalysts supported by the hemilabile phosphine P(2-MeOC6H4)3 (L1). L1 is used alone or with the coligands N,N,N′,N′‑tetramethylethylenediamine (TMEDA) or 2‑dicyclohexylphosphino‑2′,4′,6′‑triisopropylbiphenyl (XPhos). L1 maintains reactive mononuclear Pd species for efficient C–H activation; TMEDA suppresses side reactions such as homocoupling and branching; and XPhos facilitates the oxidative addition of less reactive C–X bonds. These ligand systems enable high-molecular-weight polymers (number-average molecular weight up to 347,700, yields up to 100%) with well-defined structures (cross-coupling selectivity as high as >99%) across a broad monomer scope. Devices based on these materials deliver up to 9.9% power conversion efficiency in organic photovoltaics and hole mobilities ≥0.3 cm2·V–1·s–1 in organic thin-film transistors, comparable to those from Stille coupling. These advances firmly position DArP as a practical, tin-free platform for the precise synthesis of high-performance π-conjugated DA polymers. This Review highlights our development of highly efficient and selective palladium catalysts for direct arylation polymerization (DArP). P(2-MeOC6H4)3 (L1) serves as a key supporting ligand that maintains reactive mononuclear Pd species. Coligands (TMEDA or XPhos) suppress side reactions and facilitate the activation of less reactive C–X bonds. Operating in polymer-solubilizing media (e.g., THF or toluene), these systems yield π-conjugated polymers with number-average molecular weights of up to 347,700 and cross-coupling selectivities of up to >99%; the resulting materials exhibit device-grade performance comparable to that of polymers prepared by conventional Stille coupling.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"58 2","pages":"103-116"},"PeriodicalIF":2.7,"publicationDate":"2025-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.comhttps://www.nature.com/articles/s41428-025-01107-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146117007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-15DOI: 10.1038/s41428-025-01106-9
Tomohiro Kubo, Kotaro Satoh
Poly(lactic acid) (PLA) is often used as a sustainable alternative to petrochemical-based single-use plastics, but its slow degradation can lead to waste accumulation in the environment. To address this problem, we modified the backbone structure of PLA by replacing some carbonyl oxygen atoms with sulfur atoms to impart weaker thionoester linkages. Thiocarbonyl L-lactide was copolymerized with lactide to synthesize copolymers with varying molecular weights and thionoester incorporation. The thermal properties and aqueous stability of the resulting copolymers were studied, and their selective degradation in response to specific stimuli was evaluated. This copolymerization approach represents a modular strategy for yielding degradable aliphatic polyesters that are potentially amenable to industrial use. Poly(lactic acid) (PLA) copolymers incorporating main-chain thionoester linkages were synthesized via ring-opening copolymerization of lactide and thiocarbonyl lactide. These copolymers maintain thermal and aqueous stability while exhibiting rapid, stimulus-triggered degradation through selective main-chain scission in the presence of amines. Even minimal incorporation of thionoester units was sufficient to significantly reduce molecular weight, enabling tunable degradability. This modular approach could provide a straightforward strategy for designing PLA-based polymers with enhanced end-of-life degradability while preserving their desirable properties during use.
{"title":"Enhancing the degradability of poly(lactic acid) through the introduction of main-chain thionoester linkages by ring-opening copolymerization","authors":"Tomohiro Kubo, Kotaro Satoh","doi":"10.1038/s41428-025-01106-9","DOIUrl":"10.1038/s41428-025-01106-9","url":null,"abstract":"Poly(lactic acid) (PLA) is often used as a sustainable alternative to petrochemical-based single-use plastics, but its slow degradation can lead to waste accumulation in the environment. To address this problem, we modified the backbone structure of PLA by replacing some carbonyl oxygen atoms with sulfur atoms to impart weaker thionoester linkages. Thiocarbonyl L-lactide was copolymerized with lactide to synthesize copolymers with varying molecular weights and thionoester incorporation. The thermal properties and aqueous stability of the resulting copolymers were studied, and their selective degradation in response to specific stimuli was evaluated. This copolymerization approach represents a modular strategy for yielding degradable aliphatic polyesters that are potentially amenable to industrial use. Poly(lactic acid) (PLA) copolymers incorporating main-chain thionoester linkages were synthesized via ring-opening copolymerization of lactide and thiocarbonyl lactide. These copolymers maintain thermal and aqueous stability while exhibiting rapid, stimulus-triggered degradation through selective main-chain scission in the presence of amines. Even minimal incorporation of thionoester units was sufficient to significantly reduce molecular weight, enabling tunable degradability. This modular approach could provide a straightforward strategy for designing PLA-based polymers with enhanced end-of-life degradability while preserving their desirable properties during use.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"58 2","pages":"127-135"},"PeriodicalIF":2.7,"publicationDate":"2025-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.comhttps://www.nature.com/articles/s41428-025-01106-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146116999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-02DOI: 10.1038/s41428-025-01102-z
Ryohei Ono, Hajime Kishi
A reactive oligomer for epoxy resin modifiers containing a flexible chain and imide groups is proposed. The effects of introducing imide groups into the reactive oligomer and the curing conditions of the epoxy resin with respect to the phase-separated structure and properties of the cured epoxy blends are investigated. Compared with an oligomer without imide groups, a reactive oligomer containing imide groups shows better compatibility with the epoxy resin. Although phase-separated structures are observed in the cured epoxy blends containing these oligomers, the extent of the phase separation varies with the curing temperature. Compared with blends with reactive oligomers without imide groups, cured epoxy blends with imide-based reactive oligomers exhibit a smaller phase separation size. The glass transition temperature (Tg) of the cured epoxy blends depends on the precuring temperature; a lower precuring temperature results in an increased Tg when the blend is fully cured at the final curing temperature. Compared with the unmodified cured epoxy, the cured epoxy blends with reactive oligomers show a reduction in both flexural modulus and Tg. However, the decrease in Tg is less pronounced in the cured epoxy blends with the imide-based reactive oligomer than in the blends with the reactive oligomer without imide groups. The introduction of imide groups into reactive oligomers containing long-chain aliphatic structures improved their compatibility with biphenyl-type epoxy resins. UV‒vis spectroscopy revealed the presence of intermolecular charge-transfer interactions between the biphenyl and imide groups. Cured epoxy blends containing the imide-based reactive oligomer exhibited smaller phase-separated structures than blends containing the imide-free reactive oligomer. It was found that the compatibility of the reactive oligomers influences the size of the phase-separated structures in the cured epoxy resins.
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