Oligoisoprene macromonomer, which bears a terminal vinyl group, was prepared by the metathesis degradation of high-molecular-weight polyisoprene with ethylene for coordination polymerization. The ethenolysis of polyisoprene using the 2nd-generation Grubbs catalyst (G2) at ambient pressure gave heterotelechelic (α-vinyl-ω-vinylidene) oligoisoprene, keeping the stereoregularity in high yield, whereas the 1st generation Grubbs catalyst was immediately deactivated. In such metathesis degradation, an intramolecular side reaction giving cyclic oligomers may be competitive, but ethenolysis proceeded with high selectivity, probably because of the least steric effect of ethylene. The ethenolysis is also applicable for the degradation of natural rubber-derived polyisoprene, although the catalytic activity decreased. The prepared oligoisoprene macromonomer was successfully copolymerized with ethylene using a phenoxyimine-ligated titanium catalyst, and the reactivity of the macromonomer was almost the same as that of 1-hexadecene. The oligoisoprene-grafted polyethylene showed a typical stress‒strain curve, of which the tensile modulus and yielding stress are comparable to those of linear low-density polyethylene. Oligoisoprene macromonomer, which bears a terminal vinyl group and cis-1,4 regularity, was prepared by the metathesis degradation of high-molecular-weight polyisoprene with ethylene in a high selectivity and yield. The ethenolysis is also applicable for the degradation of natural rubber-derived polyisoprene, although the catalytic activity decreased. The prepared oligoisoprene macromonomer was successfully copolymerized with ethylene similarly with 1-hexadecene using a phenoxyimine-ligated titanium catalyst. The oligoisoprene-grafted polyethylene showed a typical stress‒strain curve, of which the tensile modulus and yielding stress are comparable to those of linear low-density polyethylene.
{"title":"Selective synthesis of α-vinyl-ω-vinylidene-oligoisoprene as a macromonomer via ethenolysis of polyisoprene","authors":"Ryo Tanaka, Akane Shimmei, Riki Otsuka, Yuushou Nakayama, Takeshi Shiono","doi":"10.1038/s41428-023-00858-6","DOIUrl":"10.1038/s41428-023-00858-6","url":null,"abstract":"Oligoisoprene macromonomer, which bears a terminal vinyl group, was prepared by the metathesis degradation of high-molecular-weight polyisoprene with ethylene for coordination polymerization. The ethenolysis of polyisoprene using the 2nd-generation Grubbs catalyst (G2) at ambient pressure gave heterotelechelic (α-vinyl-ω-vinylidene) oligoisoprene, keeping the stereoregularity in high yield, whereas the 1st generation Grubbs catalyst was immediately deactivated. In such metathesis degradation, an intramolecular side reaction giving cyclic oligomers may be competitive, but ethenolysis proceeded with high selectivity, probably because of the least steric effect of ethylene. The ethenolysis is also applicable for the degradation of natural rubber-derived polyisoprene, although the catalytic activity decreased. The prepared oligoisoprene macromonomer was successfully copolymerized with ethylene using a phenoxyimine-ligated titanium catalyst, and the reactivity of the macromonomer was almost the same as that of 1-hexadecene. The oligoisoprene-grafted polyethylene showed a typical stress‒strain curve, of which the tensile modulus and yielding stress are comparable to those of linear low-density polyethylene. Oligoisoprene macromonomer, which bears a terminal vinyl group and cis-1,4 regularity, was prepared by the metathesis degradation of high-molecular-weight polyisoprene with ethylene in a high selectivity and yield. The ethenolysis is also applicable for the degradation of natural rubber-derived polyisoprene, although the catalytic activity decreased. The prepared oligoisoprene macromonomer was successfully copolymerized with ethylene similarly with 1-hexadecene using a phenoxyimine-ligated titanium catalyst. The oligoisoprene-grafted polyethylene showed a typical stress‒strain curve, of which the tensile modulus and yielding stress are comparable to those of linear low-density polyethylene.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"56 4","pages":"335-342"},"PeriodicalIF":2.8,"publicationDate":"2024-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-023-00858-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139421627","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}
As porous polymer materials with continuous epoxy skeletons and pores, epoxy monoliths are used as column fillers in HPLC, separators in lithium-ion batteries, and precursor polymers for monolith adhesion and co-continuous network polymer fabrication. Due to their unique mechanical properties and fracture behavior, epoxy monoliths can incur large deformation and are different from the bulk thermoset of epoxy resins that exhibit hard and brittle features. In this study, we prepared an epoxy monolith using 2,2’-bis(4’-glycidyloxaphenyl)propane (BADGE) and tripropylene glycol diglycidyl ether (TPGD) as epoxy resins, 4,4’-methylenebis(cyclohexylamine) (BACM) as a crosslinker, and poly(ethylene glycol) (PEG) as a porogen, and TPGD-induced effects on the pore structure and properties of the obtained monoliths were investigated. To clarify the relationship between the pore structure and the mechanical properties of the monolith, scanning electron microscopy (SEM) observations and tensile and compression tests were performed. In addition, X-ray CT imaging nondestructively revealed a change in the inner porous structure of the monolith after a large deformation occurred under various compression conditions. We clarified the effects of the TPGD addition on the monolith structure and the mechanical properties with tensile and compressive deformation. As porous polymer materials with continuous epoxy skeletons and pores, epoxy monoliths exhibit unique mechanical properties and fracture behavior different from the bulk thermoset of epoxy resins. In this article, we describe the thermal properties, pore structures, and mechanical properties of epoxy resins with tensile and compressive deformation of the monoliths. In addition, a change in the inner porous structure after large deformation was nondestructively observed by X-ray CT imaging.
{"title":"Study on the deformation and fracture of epoxy monoliths through mechanical tensile and compressive tests and X-ray CT imaging","authors":"Kazuma Aragishi, Yoshihiro Takeda, Yasuhito Suzuki, Akikazu Matsumoto","doi":"10.1038/s41428-023-00872-8","DOIUrl":"10.1038/s41428-023-00872-8","url":null,"abstract":"As porous polymer materials with continuous epoxy skeletons and pores, epoxy monoliths are used as column fillers in HPLC, separators in lithium-ion batteries, and precursor polymers for monolith adhesion and co-continuous network polymer fabrication. Due to their unique mechanical properties and fracture behavior, epoxy monoliths can incur large deformation and are different from the bulk thermoset of epoxy resins that exhibit hard and brittle features. In this study, we prepared an epoxy monolith using 2,2’-bis(4’-glycidyloxaphenyl)propane (BADGE) and tripropylene glycol diglycidyl ether (TPGD) as epoxy resins, 4,4’-methylenebis(cyclohexylamine) (BACM) as a crosslinker, and poly(ethylene glycol) (PEG) as a porogen, and TPGD-induced effects on the pore structure and properties of the obtained monoliths were investigated. To clarify the relationship between the pore structure and the mechanical properties of the monolith, scanning electron microscopy (SEM) observations and tensile and compression tests were performed. In addition, X-ray CT imaging nondestructively revealed a change in the inner porous structure of the monolith after a large deformation occurred under various compression conditions. We clarified the effects of the TPGD addition on the monolith structure and the mechanical properties with tensile and compressive deformation. As porous polymer materials with continuous epoxy skeletons and pores, epoxy monoliths exhibit unique mechanical properties and fracture behavior different from the bulk thermoset of epoxy resins. In this article, we describe the thermal properties, pore structures, and mechanical properties of epoxy resins with tensile and compressive deformation of the monoliths. In addition, a change in the inner porous structure after large deformation was nondestructively observed by X-ray CT imaging.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"56 5","pages":"529-540"},"PeriodicalIF":2.8,"publicationDate":"2024-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-023-00872-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139423452","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 : 2024-01-10DOI: 10.1038/s41428-023-00860-y
Pousali Samanta, Sourav Mete, Sunirmal Pal, Md Ezaz Hasan Khan, Priyadarsi De
Polymeric peroxide is an equimolar alternating copolymer formed by the reaction of a monomer with molecular oxygen (O2). Various polyperoxides have been successfully synthesized using different techniques, such as free radical polymerization, condensation polymerization, and insertion polymerization in the solid state. A wide variety of physical and chemical characteristics are displayed by these polyperoxides, making them attractive candidates for various applications. Due to their high exothermal degrading behavior and autocombustibility, polyperoxides are a viable alternative to fuels derived from petroleum. Additionally, polyperoxides have a wide range of applications, such as free radical initiators, curatives, biocompatible drug carriers, coating materials, dismantlable adhesives, and molding precursors. In this focused review, we report on recent efforts in developing vinyl homo- and copolyperoxides, their physicochemical behaviors, and various applications. Finally, the existing opportunities, possible challenges, and some viewpoints on future directions in vinyl polyperoxide research are highlighted. Our recent studies on the synthesis, characterization, degradation and applications of vinyl polyperoxides are reviewed. Primarily, the recent achievements in the design, biocompatibility, thermal and enzymatic degradation of water-soluble vinyl polyperoxides and copolyperoxides are described. Finally, future development possibilities and challenges of vinyl polyperoxides for various potential applications are summarised.
{"title":"Synthesis, characterization, degradation and applications of vinyl polyperoxides","authors":"Pousali Samanta, Sourav Mete, Sunirmal Pal, Md Ezaz Hasan Khan, Priyadarsi De","doi":"10.1038/s41428-023-00860-y","DOIUrl":"10.1038/s41428-023-00860-y","url":null,"abstract":"Polymeric peroxide is an equimolar alternating copolymer formed by the reaction of a monomer with molecular oxygen (O2). Various polyperoxides have been successfully synthesized using different techniques, such as free radical polymerization, condensation polymerization, and insertion polymerization in the solid state. A wide variety of physical and chemical characteristics are displayed by these polyperoxides, making them attractive candidates for various applications. Due to their high exothermal degrading behavior and autocombustibility, polyperoxides are a viable alternative to fuels derived from petroleum. Additionally, polyperoxides have a wide range of applications, such as free radical initiators, curatives, biocompatible drug carriers, coating materials, dismantlable adhesives, and molding precursors. In this focused review, we report on recent efforts in developing vinyl homo- and copolyperoxides, their physicochemical behaviors, and various applications. Finally, the existing opportunities, possible challenges, and some viewpoints on future directions in vinyl polyperoxide research are highlighted. Our recent studies on the synthesis, characterization, degradation and applications of vinyl polyperoxides are reviewed. Primarily, the recent achievements in the design, biocompatibility, thermal and enzymatic degradation of water-soluble vinyl polyperoxides and copolyperoxides are described. Finally, future development possibilities and challenges of vinyl polyperoxides for various potential applications are summarised.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"56 4","pages":"283-296"},"PeriodicalIF":2.8,"publicationDate":"2024-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-023-00860-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139411434","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}
Amine-cured epoxy resins bearing ester moieties were synthesized, and their properties, hydrolytic degradation behavior, and biomineralization were investigated. Neopentyl glycol diglycidate (NPG) was used as the epoxide and was cured with diethylenetriamine (DETA) and isophoronediamine (IPD) at different ratios. The glass transition temperatures were controlled using the composition of DETA and IPD. The cured materials containing IPD units were tolerant to neutral water but were degraded under acidic and basic conditions. Degradation in the presence of lipase also proceeded in phosphate buffer, while degradation proceeded gradually in the absence of lipase. To demonstrate their potential application as degradable biomedical materials for bone and dental repair, composites containing hydroxyapatite (HA) were prepared by curing NPG and the amines in the presence of HA. Biological bone-like apatite was grown on an NPG-IPD-HA composite by immersion in synthetic biofluid, and the amount of bone-like apatite was greater than that on the glycidyl ether analog. Amine-cured epoxy resins bearing ester moieties were synthesized, and their properties, hydrolytic degradation behavior, and biomineralization were investigated. Neopentyl glycol diglycidate (NPG) was used as the epoxide and was cured with diethylenetriamine and isophoronediamine at different ratios. The Tgs and degradability were controlled using the composition of amines. To demonstrate their potential application as degradable materials for bone and dental repair, composites containing hydroxyapatite were prepared by curing NPG and the amines in the presence of HA. Bone-like apatite was grown on a composite by immersion in synthetic biofluid.
{"title":"Hydrolytic degradation and biomineralization of amine-cured epoxy resin based on glycidate","authors":"Bungo Ochiai, Yutaka Nakazawa, Yoshimasa Matsumura, Takahiro Kawai","doi":"10.1038/s41428-023-00880-8","DOIUrl":"10.1038/s41428-023-00880-8","url":null,"abstract":"Amine-cured epoxy resins bearing ester moieties were synthesized, and their properties, hydrolytic degradation behavior, and biomineralization were investigated. Neopentyl glycol diglycidate (NPG) was used as the epoxide and was cured with diethylenetriamine (DETA) and isophoronediamine (IPD) at different ratios. The glass transition temperatures were controlled using the composition of DETA and IPD. The cured materials containing IPD units were tolerant to neutral water but were degraded under acidic and basic conditions. Degradation in the presence of lipase also proceeded in phosphate buffer, while degradation proceeded gradually in the absence of lipase. To demonstrate their potential application as degradable biomedical materials for bone and dental repair, composites containing hydroxyapatite (HA) were prepared by curing NPG and the amines in the presence of HA. Biological bone-like apatite was grown on an NPG-IPD-HA composite by immersion in synthetic biofluid, and the amount of bone-like apatite was greater than that on the glycidyl ether analog. Amine-cured epoxy resins bearing ester moieties were synthesized, and their properties, hydrolytic degradation behavior, and biomineralization were investigated. Neopentyl glycol diglycidate (NPG) was used as the epoxide and was cured with diethylenetriamine and isophoronediamine at different ratios. The Tgs and degradability were controlled using the composition of amines. To demonstrate their potential application as degradable materials for bone and dental repair, composites containing hydroxyapatite were prepared by curing NPG and the amines in the presence of HA. Bone-like apatite was grown on a composite by immersion in synthetic biofluid.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"56 4","pages":"409-417"},"PeriodicalIF":2.8,"publicationDate":"2024-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-023-00880-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139411550","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}
Acrylate polymerizations catalyzed by Lewis pairs (LP) composed of B(C6F5)3 and various Lewis bases (phosphines, amines, and an N-heterocyclic carbene) in dichloromethane were investigated using two procedures based on different monomer/catalyst addition sequences. In procedure 1, Lewis bases were added to B(C6F5)3-activated n-butyl acrylate (nBA), and the polymerization proceeded quantitatively using all Lewis bases at a wide temperature range (−60 °C to 30 °C). A low nucleophilic Lewis base Et3N also initiated the polymerization even at −60 °C. However, t-butyl acrylate was not polymerized, as LP promoted its conversion into acrylic acid and isobutene. In procedure 2, nBA was added to interacting LPs; the type of Lewis base significantly affected the polymerization results. Specifically, polymerization was not observed when 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and PnBu3 were applied; however, similar to the reaction in procedure 1, PPh3, PtBu3, and 1,4-diazabicyclo[2.2.2]octane (DABCO) initiated nBA polymerization. The pairing interactions between LBs/B(C6F5)3 (PPh3, Et3N, DBU, and DABCO) were investigated using the shift of 19F nuclear magnetic resonance signals, demonstrating that weak interacting LPs efficiently initiated the polymerizations in procedure 2. Acrylate polymerizations catalyzed by Lewis pairs (LP) composed of B(C6F5)3 and various Lewis bases were investigated using two procedures based on different monomer/catalyst addition sequences. When Lewis bases were added to B(C6F5)3-activated n-butyl acrylate (nBA) (procedure 1), the polymerization proceeded quantitatively using all Lewis bases. In contrast, the type of Lewis base significantly affected the polymerization results when nBA was added to interacting LPs (procedure 2). 19F nuclear magnetic resonance analysis of the LPs indicated that weakly interacting LPs efficiently initiated the polymerizations in procedure 2.
{"title":"B(C6F5)3-based Lewis pair-catalyzed acrylate polymerization: Lewis base effects on pairing interactions","authors":"Yuka Naganawa, Kazumasa Mori, Shin-ichi Matsuoka, Masato Suzuki","doi":"10.1038/s41428-023-00868-4","DOIUrl":"10.1038/s41428-023-00868-4","url":null,"abstract":"Acrylate polymerizations catalyzed by Lewis pairs (LP) composed of B(C6F5)3 and various Lewis bases (phosphines, amines, and an N-heterocyclic carbene) in dichloromethane were investigated using two procedures based on different monomer/catalyst addition sequences. In procedure 1, Lewis bases were added to B(C6F5)3-activated n-butyl acrylate (nBA), and the polymerization proceeded quantitatively using all Lewis bases at a wide temperature range (−60 °C to 30 °C). A low nucleophilic Lewis base Et3N also initiated the polymerization even at −60 °C. However, t-butyl acrylate was not polymerized, as LP promoted its conversion into acrylic acid and isobutene. In procedure 2, nBA was added to interacting LPs; the type of Lewis base significantly affected the polymerization results. Specifically, polymerization was not observed when 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and PnBu3 were applied; however, similar to the reaction in procedure 1, PPh3, PtBu3, and 1,4-diazabicyclo[2.2.2]octane (DABCO) initiated nBA polymerization. The pairing interactions between LBs/B(C6F5)3 (PPh3, Et3N, DBU, and DABCO) were investigated using the shift of 19F nuclear magnetic resonance signals, demonstrating that weak interacting LPs efficiently initiated the polymerizations in procedure 2. Acrylate polymerizations catalyzed by Lewis pairs (LP) composed of B(C6F5)3 and various Lewis bases were investigated using two procedures based on different monomer/catalyst addition sequences. When Lewis bases were added to B(C6F5)3-activated n-butyl acrylate (nBA) (procedure 1), the polymerization proceeded quantitatively using all Lewis bases. In contrast, the type of Lewis base significantly affected the polymerization results when nBA was added to interacting LPs (procedure 2). 19F nuclear magnetic resonance analysis of the LPs indicated that weakly interacting LPs efficiently initiated the polymerizations in procedure 2.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"56 3","pages":"145-151"},"PeriodicalIF":2.8,"publicationDate":"2024-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-023-00868-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139094023","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}
The valorization of lignin to value-added basic chemicals is one of the most important technologies for efficient carbon recycling. While many catalytic systems have been developed for cleavage of monolignol linkages, especially for β-O-4 structures, the low solubility of lignin, which originates from its complicated polymeric structure, often makes it difficult to apply these catalytic process to degradation of real lignin-derived materials. Here, we investigated the degradation of poly(ethylene glycol)-modified lignin with transition metal complexes. Monolignols (4-methyl, 4-ethyl- and 4-propyl-guaiacol) were obtained as the degradation products. Although low solubility after detachment of the PEG moiety hampered efficient degradation, the addition of PEG for in situ protection of the hydroxy group was effective in maintaining the lignin solubility and improving the monolignol yields. The hydrogenolysis of PEG-modified soluble lignin was investigated with series of transition metal complexes to afford alkyl guaiacols. Although the introduced PEG moiety was also susceptible against the hydrogenolysis, in situ modification in PEG solvent was found effective for maintaining the lignin soluble and improved degradation efficiency.
{"title":"Hydrogenative degradation of PEG-functionalized lignin","authors":"Shuhei Kusumoto, Takuya Higashi, Yusuke Matsumoto, Tatsuhiko Yamada, Kyoko Nozaki","doi":"10.1038/s41428-023-00867-5","DOIUrl":"10.1038/s41428-023-00867-5","url":null,"abstract":"The valorization of lignin to value-added basic chemicals is one of the most important technologies for efficient carbon recycling. While many catalytic systems have been developed for cleavage of monolignol linkages, especially for β-O-4 structures, the low solubility of lignin, which originates from its complicated polymeric structure, often makes it difficult to apply these catalytic process to degradation of real lignin-derived materials. Here, we investigated the degradation of poly(ethylene glycol)-modified lignin with transition metal complexes. Monolignols (4-methyl, 4-ethyl- and 4-propyl-guaiacol) were obtained as the degradation products. Although low solubility after detachment of the PEG moiety hampered efficient degradation, the addition of PEG for in situ protection of the hydroxy group was effective in maintaining the lignin solubility and improving the monolignol yields. The hydrogenolysis of PEG-modified soluble lignin was investigated with series of transition metal complexes to afford alkyl guaiacols. Although the introduced PEG moiety was also susceptible against the hydrogenolysis, in situ modification in PEG solvent was found effective for maintaining the lignin soluble and improved degradation efficiency.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"56 4","pages":"353-357"},"PeriodicalIF":2.8,"publicationDate":"2024-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-023-00867-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139096419","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 : 2024-01-04DOI: 10.1038/s41428-023-00870-w
Yasunori Minami, Rena Honobe, Yuuki Inagaki, Kazuhiko Sato, Masaru Yoshida
Herein we describe the alcoholysis of super engineering plastics under mild conditions. Treatment of polysulfone (PSU) with methanol mediated by sodium hydroxide in 1,3-dimethyl-2-imidazolidinone (DMI) at 80 °C resulted in facile depolymerization to form bis(4-methoxyphenyl)sulfone and 4,4’-(propane-2,2-diyl)diphenol (bisphenol A) in high yields. These products were readily isolated by simple filtration. The DMI solvent effectively promoted depolymerization and allowed insoluble resins such as polyetheretherketone (PEEK) to undergo the reaction. This method was applicable to other alcohols, such as ethanol and isopropyl alcohol. The depolymerization of super engineering plastics such as polysulfone (PSU) smoothly proceeded in the presence of methanol mediated by sodium hydroxide in 1,3-dimethyl-2-imidazolidinone (DMI) at 80 °C to form bis(4-methoxyphenyl)sulfone and 4,4’-(propane-2,2-diyl)diphenol (bisphenol A) in high yields. These products were readily isolated by simple filtration. The DMI solvent effectively promoted depolymerization and allowed insoluble resins such as polyetheretherketone (PEEK) to undergo the reaction. This method was applicable to other alcohols, such as ethanol and isopropyl alcohol.
在此，我们介绍了超级工程塑料在温和条件下的醇解过程。在 1,3-二甲基-2-咪唑烷酮（DMI）中以氢氧化钠为介质，在 80 °C 下用甲醇处理聚砜（PSU），可轻松解聚形成高产率的双（4-甲氧基苯基）砜和 4,4'-（丙烷-2,2-二基）二苯酚（双酚 A）。这些产物很容易通过简单的过滤分离出来。DMI 溶剂可有效促进解聚，并使聚醚醚酮（PEEK）等不溶性树脂发生反应。这种方法也适用于其他醇类，如乙醇和异丙醇。
{"title":"Alcoholysis of oxyphenylene-based super engineering plastics mediated by readily available bases","authors":"Yasunori Minami, Rena Honobe, Yuuki Inagaki, Kazuhiko Sato, Masaru Yoshida","doi":"10.1038/s41428-023-00870-w","DOIUrl":"10.1038/s41428-023-00870-w","url":null,"abstract":"Herein we describe the alcoholysis of super engineering plastics under mild conditions. Treatment of polysulfone (PSU) with methanol mediated by sodium hydroxide in 1,3-dimethyl-2-imidazolidinone (DMI) at 80 °C resulted in facile depolymerization to form bis(4-methoxyphenyl)sulfone and 4,4’-(propane-2,2-diyl)diphenol (bisphenol A) in high yields. These products were readily isolated by simple filtration. The DMI solvent effectively promoted depolymerization and allowed insoluble resins such as polyetheretherketone (PEEK) to undergo the reaction. This method was applicable to other alcohols, such as ethanol and isopropyl alcohol. The depolymerization of super engineering plastics such as polysulfone (PSU) smoothly proceeded in the presence of methanol mediated by sodium hydroxide in 1,3-dimethyl-2-imidazolidinone (DMI) at 80 °C to form bis(4-methoxyphenyl)sulfone and 4,4’-(propane-2,2-diyl)diphenol (bisphenol A) in high yields. These products were readily isolated by simple filtration. The DMI solvent effectively promoted depolymerization and allowed insoluble resins such as polyetheretherketone (PEEK) to undergo the reaction. This method was applicable to other alcohols, such as ethanol and isopropyl alcohol.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"56 4","pages":"369-377"},"PeriodicalIF":2.8,"publicationDate":"2024-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-023-00870-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139094029","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}
Cell behaviors are highly sensitive to the surrounding environment. Therefore, in regulating cells, biomaterial substrates should be designed so their properties are similar to the surrounding environments of the cells. For cell regulation, we designed dual stimuli-responsive gels whose physical (elastic modulus) and chemical (hydrophilicity) properties can be changed by varying the UV exposure time and temperature, respectively. A dual stimuli-responsive polymer with photodimerizable groups and temperature-responsive moieties was prepared by copolymerizing 7-methacryloyloxycoumarin (MAC) and methoxyoligoethylene glycol methacrylate (OEGMA). The resulting polymers (P(MAC-co-OEGMA)) had lower critical solution temperatures (LCSTs), which depended on the compositions. A buffer solution containing P(MAC-co-OEGMA) was exposed to ultraviolet light (UV) for gelation, and the elastic modulus increased with increasing exposure time. The cell behavior, including adhesion and spreading, on the surfaces of these gels was investigated. Most of the cells adhered to P(MAC-co-OEGMA) gels with higher elastic moduli, and the cells were spread more effectively at temperatures above the LCST. This was because cell adhesion and spreading were strongly influenced by the physical and chemical properties of the P(MAC-co-OEGMA) gels, which were regulated by varying the UV exposure time and temperature. A buffer solution of dual stimuli-responsive polymer with photodimerizable groups and temperature-responsive moieties undergoes a phase transition from a sol state to a gel state by exposure to ultraviolet light. The resulting gels changed the physical (elastic modulus) and chemical (hydrophilicity) properties by varying UV exposure time and temperature, respectively. Cell adhesion, spreading, and proliferation were strongly influenced by the physical and chemical properties of the polymer gels, which were regulated by varying UV exposure time and temperature.
{"title":"Design of dual stimuli-responsive gels with physical and chemical properties that vary in response to light and temperature and cell behavior on their surfaces","authors":"Masaaki Okihara, Akana Matsuda, Akifumi Kawamura, Takashi Miyata","doi":"10.1038/s41428-023-00865-7","DOIUrl":"10.1038/s41428-023-00865-7","url":null,"abstract":"Cell behaviors are highly sensitive to the surrounding environment. Therefore, in regulating cells, biomaterial substrates should be designed so their properties are similar to the surrounding environments of the cells. For cell regulation, we designed dual stimuli-responsive gels whose physical (elastic modulus) and chemical (hydrophilicity) properties can be changed by varying the UV exposure time and temperature, respectively. A dual stimuli-responsive polymer with photodimerizable groups and temperature-responsive moieties was prepared by copolymerizing 7-methacryloyloxycoumarin (MAC) and methoxyoligoethylene glycol methacrylate (OEGMA). The resulting polymers (P(MAC-co-OEGMA)) had lower critical solution temperatures (LCSTs), which depended on the compositions. A buffer solution containing P(MAC-co-OEGMA) was exposed to ultraviolet light (UV) for gelation, and the elastic modulus increased with increasing exposure time. The cell behavior, including adhesion and spreading, on the surfaces of these gels was investigated. Most of the cells adhered to P(MAC-co-OEGMA) gels with higher elastic moduli, and the cells were spread more effectively at temperatures above the LCST. This was because cell adhesion and spreading were strongly influenced by the physical and chemical properties of the P(MAC-co-OEGMA) gels, which were regulated by varying the UV exposure time and temperature. A buffer solution of dual stimuli-responsive polymer with photodimerizable groups and temperature-responsive moieties undergoes a phase transition from a sol state to a gel state by exposure to ultraviolet light. The resulting gels changed the physical (elastic modulus) and chemical (hydrophilicity) properties by varying UV exposure time and temperature, respectively. Cell adhesion, spreading, and proliferation were strongly influenced by the physical and chemical properties of the polymer gels, which were regulated by varying UV exposure time and temperature.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"56 3","pages":"193-204"},"PeriodicalIF":2.8,"publicationDate":"2023-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-023-00865-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139051596","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 : 2023-12-25DOI: 10.1038/s41428-023-00857-7
Kenichi Oyaizu
Redox-active polymers with charging/discharging reversibility are employed to develop electrode-active materials in organic batteries, which are characterized by high power rates, flexibility/bendability, and environmentally benign properties. Reversible charge storage with polymers is achieved by redox “bistability” and exchange reactions. Redox bistability is a feature of electrochemical reversibility, which refers to the properties of redox pairs in which both the reduced and oxidized states are chemically robust and do not fade during substantial storage periods. The electron self-exchange reactions of the redox-active sites populated in the polymer layer give rise to charge propagation in support of exhaustive charging and discharging. The concept of charge storage reversibility is extended to hydrogen storage reversibility based on the bistability of the hydrogenation/dehydrogenation pair and the electron/proton exchange reaction, creating hydrogen carrier polymers as a new class of energy-related functional polymers. In this review, we show that reversibility of charge storage occurs in polymers with bistable redox-active groups populated in the repeat units of a nonconjugated backbone, especially when an electron self-exchange reaction spreads throughout the polymer. We will also show that extending the idea of electron exchange to electron/proton exchange leads to reversible hydrogen storage based on the bistability of hydrogenated and dehydrogenated states and the equilibrium for hydrogenation.
{"title":"Reversible and high-density energy storage with polymers populated with bistable redox sites","authors":"Kenichi Oyaizu","doi":"10.1038/s41428-023-00857-7","DOIUrl":"10.1038/s41428-023-00857-7","url":null,"abstract":"Redox-active polymers with charging/discharging reversibility are employed to develop electrode-active materials in organic batteries, which are characterized by high power rates, flexibility/bendability, and environmentally benign properties. Reversible charge storage with polymers is achieved by redox “bistability” and exchange reactions. Redox bistability is a feature of electrochemical reversibility, which refers to the properties of redox pairs in which both the reduced and oxidized states are chemically robust and do not fade during substantial storage periods. The electron self-exchange reactions of the redox-active sites populated in the polymer layer give rise to charge propagation in support of exhaustive charging and discharging. The concept of charge storage reversibility is extended to hydrogen storage reversibility based on the bistability of the hydrogenation/dehydrogenation pair and the electron/proton exchange reaction, creating hydrogen carrier polymers as a new class of energy-related functional polymers. In this review, we show that reversibility of charge storage occurs in polymers with bistable redox-active groups populated in the repeat units of a nonconjugated backbone, especially when an electron self-exchange reaction spreads throughout the polymer. We will also show that extending the idea of electron exchange to electron/proton exchange leads to reversible hydrogen storage based on the bistability of hydrogenated and dehydrogenated states and the equilibrium for hydrogenation.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"56 3","pages":"127-144"},"PeriodicalIF":2.8,"publicationDate":"2023-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-023-00857-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139035677","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}
Using X-ray absorption spectroscopy (XAS) with linearly polarized soft X-rays, we investigated the local conformation of poly(methyl methacrylate) (PMMA) adsorbed to a SiOx/Si(111) surface. The preedge intensity of the O K-edge XAS for PMMA, originating from the O 1s → π* transition at a C=O group in the side chain, was stronger for vertically polarized incident X-rays than for horizontally polarized ones. Conversely, the XAS intensity originating from the O 1s → σ* transition showed the opposite trend. These findings suggest that the C=O group in the side chain of PMMA exhibited preferential orientation rather than an amorphous arrangement. To gain further insights, we conducted a depth profile analysis of the local conformation of PMMA using XAS combined with an argon gas cluster ion beam (GCIB). GCIB-XAS analysis revealed that the orientation of the C=O group in the side chain of PMMA differs between the region from the SiOx interface to a distance on the order of 1 nanometer and the bulk PMMA region. The aggregation states from the interface to the bulk of the adhesive/adherend is a key to unraveling adhesion at the molecular level. We applied X-ray absorption spectroscopy (XAS) in combination with an Ar gas cluster ion beam (Ar GCIB) to poly(methyl methacrylate) (PMMA) films adsorbed onto a SiOx/Si(111) surface. GCIB-XAS analysis revealed that the orientation of the C=O group in the side chain of PMMA differs between the region from the SiOx interface to a distance on the order of 1 nanometer and the bulk PMMA region.
我们利用线性偏振软 X 射线的 X 射线吸收光谱 (XAS) 研究了吸附在 SiOx/Si(111)表面上的聚甲基丙烯酸甲酯 (PMMA) 的局部构象。聚甲基丙烯酸甲酯（PMMA）的 O K 边 XAS 前沿强度源自侧链中 C=O 基团上的 O 1s → π* 转变，垂直偏振入射 X 射线的前沿强度比水平偏振入射 X 射线的前沿强度大。相反，来自 O 1s → σ* 转变的 XAS 强度则呈现出相反的趋势。这些发现表明，PMMA 侧链中的 C=O 基团表现出优先取向，而不是无定形排列。为了进一步了解情况，我们使用 XAS 结合氩气簇离子束 (GCIB) 对 PMMA 的局部构象进行了深度剖面分析。GCIB-XAS 分析表明，PMMA 侧链中 C=O 基团的取向在距离 SiOx 界面 1 纳米左右的区域与 PMMA 主体区域之间存在差异。
{"title":"Depth analysis of local conformation in poly(methyl methacrylate) adsorbed onto SiOx studied by soft X-ray absorption spectroscopy combined with an Ar gas cluster ion beam","authors":"Hiroyuki Yamane, Masaki Oura, Daisuke Kawaguchi, Kiyofumi Nitta, Oki Sekizawa, Tetsuya Ishikawa, Satoru Yamamoto, Keiji Tanaka, Takaki Hatsui","doi":"10.1038/s41428-023-00864-8","DOIUrl":"10.1038/s41428-023-00864-8","url":null,"abstract":"Using X-ray absorption spectroscopy (XAS) with linearly polarized soft X-rays, we investigated the local conformation of poly(methyl methacrylate) (PMMA) adsorbed to a SiOx/Si(111) surface. The preedge intensity of the O K-edge XAS for PMMA, originating from the O 1s → π* transition at a C=O group in the side chain, was stronger for vertically polarized incident X-rays than for horizontally polarized ones. Conversely, the XAS intensity originating from the O 1s → σ* transition showed the opposite trend. These findings suggest that the C=O group in the side chain of PMMA exhibited preferential orientation rather than an amorphous arrangement. To gain further insights, we conducted a depth profile analysis of the local conformation of PMMA using XAS combined with an argon gas cluster ion beam (GCIB). GCIB-XAS analysis revealed that the orientation of the C=O group in the side chain of PMMA differs between the region from the SiOx interface to a distance on the order of 1 nanometer and the bulk PMMA region. The aggregation states from the interface to the bulk of the adhesive/adherend is a key to unraveling adhesion at the molecular level. We applied X-ray absorption spectroscopy (XAS) in combination with an Ar gas cluster ion beam (Ar GCIB) to poly(methyl methacrylate) (PMMA) films adsorbed onto a SiOx/Si(111) surface. GCIB-XAS analysis revealed that the orientation of the C=O group in the side chain of PMMA differs between the region from the SiOx interface to a distance on the order of 1 nanometer and the bulk PMMA region.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"56 3","pages":"215-220"},"PeriodicalIF":2.8,"publicationDate":"2023-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-023-00864-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139051482","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}
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