Songsu Kang, Sherilyn J. Lu, Minyeong Cho, Youngsang Cho, Prakash R. Sultane, Christopher W. Bielawski
The C1 polymerization of substituted diazomethanes, including diazoethane and 2,2,2-trifluoromethyl diazomethane, are reported. N-heterocyclic carbene copper complexes were employed as catalysts for the polymerization reactions and afforded the corresponding persubstituted polymers containing methyl or trifluoromethyl units along the backbones of the polymer products. The polymers were characterized using size exclusion chromatography, a variety of spectroscopic and thermal techniques, and contact angle measurements. Polymers prepared using the C1 polymerization methodology described herein are more hydrophobic than related polymers that were obtained using a standard C2 polymerization method and the fluorinated polymers were determined to be more hydrophobic than their hydrogenated analogues. The relationship between fluorine content and wettability of persubstituted polymers was quantified.
{"title":"N-heterocyclic carbene copper complexes catalyze the C1 polymerization of substituted diazomethanes","authors":"Songsu Kang, Sherilyn J. Lu, Minyeong Cho, Youngsang Cho, Prakash R. Sultane, Christopher W. Bielawski","doi":"10.1002/pol.20240591","DOIUrl":"https://doi.org/10.1002/pol.20240591","url":null,"abstract":"The C1 polymerization of substituted diazomethanes, including diazoethane and 2,2,2-trifluoromethyl diazomethane, are reported. <i>N</i>-heterocyclic carbene copper complexes were employed as catalysts for the polymerization reactions and afforded the corresponding persubstituted polymers containing methyl or trifluoromethyl units along the backbones of the polymer products. The polymers were characterized using size exclusion chromatography, a variety of spectroscopic and thermal techniques, and contact angle measurements. Polymers prepared using the C1 polymerization methodology described herein are more hydrophobic than related polymers that were obtained using a standard C2 polymerization method and the fluorinated polymers were determined to be more hydrophobic than their hydrogenated analogues. The relationship between fluorine content and wettability of persubstituted polymers was quantified.","PeriodicalId":16888,"journal":{"name":"Journal of Polymer Science","volume":"23 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142261570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yuya Tanaka, Nanae Tanaka, Daisuke Aoki, Koji Arimitsu
In recent years, there has been a growing demand for UV‐curable hard coatings because they offer several advantages, for example, lower energy consumption and the absence of volatile organic compound emissions. Anionic UV curing with photobase generators (PBGs), such as epoxy–thiol cross‐linking, enables curing under ambient conditions. However, designing a room‐temperature photoanionic curing system for epoxy–thiols remains challenging due to the complex effects of resin combinations on the cured products, thus making it difficult to prepare films with high hardness. Herein, we present a controlled reaction design for an anionic UV‐curing system by combining the chemical structures of epoxy resins and multifunctional thiols. The anionic UV‐curing system using PBGs that generate organic superbases demonstrated UV‐delayed curability, as evidenced by FT‐IR and photorheological analyses. To achieve high hardness, it was necessary to create the thiols with ultrarigid structures; epoxy resins with a bisphenol F structure were optimal for reacting with thiols for ultrarigid structures. This combination afforded an indentation hardness of 262 MPa with an epoxy conversion rate of 77% even at room temperature.
近年来，人们对紫外线固化硬质涂料的需求越来越大，因为这种涂料具有多种优点，例如能耗低、无挥发性有机化合物排放等。使用光碱发生器（PBG）（如环氧硫醇交联）的阴离子紫外线固化可在环境条件下固化。然而，由于树脂组合对固化产物的复杂影响，设计环氧硫醇的室温光阴离子固化系统仍然具有挑战性，因此很难制备出具有高硬度的薄膜。在此，我们结合环氧树脂和多功能硫醇的化学结构，提出了一种阴离子紫外线固化体系的受控反应设计。通过傅立叶变换红外光谱（FT-IR）和光流变学分析，使用生成有机超碱的 PBGs 的阴离子紫外线固化体系表现出紫外线延迟固化性。为了获得高硬度，有必要制造出具有超硬结构的硫醇；具有双酚 F 结构的环氧树脂最适合与硫醇反应制造超硬结构。这种组合即使在室温下也能产生 262 兆帕的压痕硬度和 77% 的环氧树脂转化率。
{"title":"Rational design of a room‐temperature curing method, based on the epoxy–thiol click reaction, for UV‐curable hard coatings with ultrahigh strength and adhesion","authors":"Yuya Tanaka, Nanae Tanaka, Daisuke Aoki, Koji Arimitsu","doi":"10.1002/pol.20240661","DOIUrl":"https://doi.org/10.1002/pol.20240661","url":null,"abstract":"In recent years, there has been a growing demand for UV‐curable hard coatings because they offer several advantages, for example, lower energy consumption and the absence of volatile organic compound emissions. Anionic UV curing with photobase generators (PBGs), such as epoxy–thiol cross‐linking, enables curing under ambient conditions. However, designing a room‐temperature photoanionic curing system for epoxy–thiols remains challenging due to the complex effects of resin combinations on the cured products, thus making it difficult to prepare films with high hardness. Herein, we present a controlled reaction design for an anionic UV‐curing system by combining the chemical structures of epoxy resins and multifunctional thiols. The anionic UV‐curing system using PBGs that generate organic superbases demonstrated UV‐delayed curability, as evidenced by FT‐IR and photorheological analyses. To achieve high hardness, it was necessary to create the thiols with ultrarigid structures; epoxy resins with a bisphenol F structure were optimal for reacting with thiols for ultrarigid structures. This combination afforded an indentation hardness of 262 MPa with an epoxy conversion rate of 77% even at room temperature.","PeriodicalId":16888,"journal":{"name":"Journal of Polymer Science","volume":"212 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142261884","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Conjugated tetrazine‐containing polymers that undergo inverse electron demand Diels‐Alder (IEDDA) reactions with trans‐cyclooctenes are interesting not only for their intrinsic optoelectronic properties, but also their interactions with π‐conjugated surfaces. Here, we prepared a series of poly(fluorene‐co‐tetrazine) polymers and carried out IEDDA reactions to decorate them with hydroxyl, hexadecyl, or triethylene glycol side chains. The polymers were investigated pre‐ and post‐IEDDA coupling in terms of their ability to disperse single‐walled carbon nanotubes (SWNTs) in organic solvent. It was found that polymer molecular weight, side chain structure, and degree of conjugation all impacted the quality of SWNT dispersions. While the starting poly(fluorene‐co‐tetrazine) polymer produced concentrated dispersions, the post‐IEDDA polymer containing dihydropyridazine groups did not produce dispersions of equal concentration. However, upon oxidation to the fully aromatic pyridazines, the polymers regained their ability to form concentrated dispersions. Furthermore, the post‐IEDDA polymers exhibited increased selectivity toward metallic SWNTs relative to the starting polymer. Due to the efficiency of the IEDDA reaction, it was also possible to use this chemistry to derivatize the nanotube complex with poly(fluorene‐co‐tetrazine) post‐dispersion. Overall, this work demonstrates the first use of reactive polytetrazines to disperse SWNTs, allowing rapid modification of polymer‐nanotube complexes.
{"title":"Exploring the reactivity and interactions of a poly(fluorene‐co‐tetrazine)‐conjugated polymer with Single‐walled Carbon Nanotubes","authors":"Alexandra L. Ly, Alex Adronov","doi":"10.1002/pol.20240593","DOIUrl":"https://doi.org/10.1002/pol.20240593","url":null,"abstract":"Conjugated tetrazine‐containing polymers that undergo inverse electron demand Diels‐Alder (IEDDA) reactions with <jats:italic>trans</jats:italic>‐cyclooctenes are interesting not only for their intrinsic optoelectronic properties, but also their interactions with π‐conjugated surfaces. Here, we prepared a series of poly(fluorene‐<jats:italic>co</jats:italic>‐tetrazine) polymers and carried out IEDDA reactions to decorate them with hydroxyl, hexadecyl, or triethylene glycol side chains. The polymers were investigated pre‐ and post‐IEDDA coupling in terms of their ability to disperse single‐walled carbon nanotubes (SWNTs) in organic solvent. It was found that polymer molecular weight, side chain structure, and degree of conjugation all impacted the quality of SWNT dispersions. While the starting poly(fluorene‐<jats:italic>co</jats:italic>‐tetrazine) polymer produced concentrated dispersions, the post‐IEDDA polymer containing dihydropyridazine groups did not produce dispersions of equal concentration. However, upon oxidation to the fully aromatic pyridazines, the polymers regained their ability to form concentrated dispersions. Furthermore, the post‐IEDDA polymers exhibited increased selectivity toward metallic SWNTs relative to the starting polymer. Due to the efficiency of the IEDDA reaction, it was also possible to use this chemistry to derivatize the nanotube complex with poly(fluorene‐<jats:italic>co</jats:italic>‐tetrazine) post‐dispersion. Overall, this work demonstrates the first use of reactive polytetrazines to disperse SWNTs, allowing rapid modification of polymer‐nanotube complexes.","PeriodicalId":16888,"journal":{"name":"Journal of Polymer Science","volume":"21 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142261876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The cover image is based on the Article Polyurethanes by ring-opening polymerization initiated from alcohol moiety-tethering acylazide by Yosuke Akae and Patrick Theato, https://doi.org/10.1002/pol.20240092. The cover image by Yosuke Akae shows the unique utility of the orthogonal reagent by using the analogy of Japanese archery (Kyudo). The reagent is able to play a role as (1) initiator of ring-opening polymerization to give polyester (an arrow), and (2) AB-type monomer to afford polyurethane (a bow). When both are combined (bow and arrow are completed), a unique polyurethane structure, which has been difficult to be addressed by other method, is easily synthesized. The player depicted as a shadow is the author himself in the background image of Japanese castle.
封面图片来自 Yosuke Akae 和 Patrick Theato 的文章《由乙醇分子系链酰肼引发的开环聚合聚氨酯》，https://doi.org/10.1002/pol.20240092。Yosuke Akae 的封面图片以日本射箭（Kyudo）为类比，展示了正交试剂的独特作用。该试剂可用作：(1) 开环聚合的引发剂，生成聚酯（箭）；(2) AB 型单体，生成聚氨酯（弓）。当两者结合时（弓箭完成），就能轻松合成出一种独特的聚氨酯结构，而这种结构是其他方法难以解决的。在日本城堡的背景图片中，被描绘成影子的玩家就是作者本人。
{"title":"Cover Image, Volume 62, Issue 18","authors":"","doi":"10.1002/pola.31317","DOIUrl":"https://doi.org/10.1002/pola.31317","url":null,"abstract":"<p>The cover image is based on the Article <i>Polyurethanes by ring-opening polymerization initiated from alcohol moiety-tethering acylazide</i> by Yosuke Akae and Patrick Theato, https://doi.org/10.1002/pol.20240092. The cover image by Yosuke Akae shows the unique utility of the orthogonal reagent by using the analogy of Japanese archery (Kyudo). The reagent is able to play a role as (1) initiator of ring-opening polymerization to give polyester (an arrow), and (2) AB-type monomer to afford polyurethane (a bow). When both are combined (bow and arrow are completed), a unique polyurethane structure, which has been difficult to be addressed by other method, is easily synthesized. The player depicted as a shadow is the author himself in the background image of Japanese castle.\u0000 <figure>\u0000 <div><picture>\u0000 <source></source></picture><p></p>\u0000 </div>\u0000 </figure></p>","PeriodicalId":16888,"journal":{"name":"Journal of Polymer Science","volume":"62 18","pages":"i"},"PeriodicalIF":3.9,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/pola.31317","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142234010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Two‐dimensional (2D) inorganic fillers can significantly improve the properties of polyolefins and broaden their application areas. In this study, high‐performance polyethylene (PE)/siloxene nanocomposites were prepared by in situ polymerization using layered siloxene‐supported vanadium (V)‐based catalysts. The siloxene‐supported V‐based catalysts have highly dispersed active sites and excellent catalytic performance for ethylene polymerization compared to VOCl3 catalysts. The catalytic activity of the siloxene‐supported V‐based catalysts for the polymerization of ethylene was significantly better than that of the VOCl3 catalysts at the same catalyst feed. During in situ polymerization, the layered siloxene fillers exhibited uniform dispersion in the PE matrix. Moreover, the addition of a very small amount (1.12 wt%) of siloxene filler significantly improved the thermal stability and mechanical performance of PE. Therefore, this study presents an effective method to fabricate PE with excellent properties.
二维（2D）无机填料可显著改善聚烯烃的性能，拓宽其应用领域。本研究使用层状硅氧烷支撑的钒（V）基催化剂，通过原位聚合制备了高性能聚乙烯（PE）/硅氧烷纳米复合材料。与 VOCl3 催化剂相比，硅氧烷支撑的 V 基催化剂具有高度分散的活性位点和优异的乙烯聚合催化性能。在催化剂进料相同的情况下，硅氧烷支撑的 V 型催化剂对乙烯聚合的催化活性明显优于 VOCl3 催化剂。在原位聚合过程中，层状硅氧烷填料在聚乙烯基体中表现出均匀的分散性。此外，添加极少量（1.12 wt%）的硅氧烷填料可显著提高聚乙烯的热稳定性和机械性能。因此，本研究提出了一种制造具有优异性能的聚乙烯的有效方法。
{"title":"Enhanced properties of polyethylene through in situ polymerization with siloxene‐supported vanadium‐based catalysts","authors":"Xin Yan, Yuying Zhou, Hao Wu, Chen Liu, Chenghan Huang, Weiwei He, Liang Fang, Hexin Zhang, Jianming Yang, KeunByoung Yoon","doi":"10.1002/pol.20240334","DOIUrl":"https://doi.org/10.1002/pol.20240334","url":null,"abstract":"Two‐dimensional (2D) inorganic fillers can significantly improve the properties of polyolefins and broaden their application areas. In this study, high‐performance polyethylene (PE)/siloxene nanocomposites were prepared by in situ polymerization using layered siloxene‐supported vanadium (V)‐based catalysts. The siloxene‐supported V‐based catalysts have highly dispersed active sites and excellent catalytic performance for ethylene polymerization compared to VOCl<jats:sub>3</jats:sub> catalysts. The catalytic activity of the siloxene‐supported V‐based catalysts for the polymerization of ethylene was significantly better than that of the VOCl<jats:sub>3</jats:sub> catalysts at the same catalyst feed. During in situ polymerization, the layered siloxene fillers exhibited uniform dispersion in the PE matrix. Moreover, the addition of a very small amount (1.12 wt%) of siloxene filler significantly improved the thermal stability and mechanical performance of PE. Therefore, this study presents an effective method to fabricate PE with excellent properties.","PeriodicalId":16888,"journal":{"name":"Journal of Polymer Science","volume":"74 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142261879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The renewable and biosynthetic molecule, vanillin, was used in the preparation of a new phthalonitrile resin (PN), containing two phthalonitrile groups without pre‐modification of the vanillin structure. This PN resin was characterized thoroughly by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), nuclear magnetic resonance (NMR) spectroscopy, rheometry, Fourier transform infrared spectroscopy (FTIR), and single‐crystal X‐ray diffraction (XRD). The monomer exhibited excellent rheometric viscosities below 250 cP at processing temperatures and a good pot life. After complete curing, the PN polymer exhibited thermal stability above 500°C, a glass transition temperature (Tg) above the final postcure temperature of 380°C, and exceptional retention of structural integrity. These results highlight a vanillin‐derived PN resin is an excellent candidate for a variety of applications where high temperature and mechanical stability over a large temperature range are required.
{"title":"Synthesis and properties of a sustainable, vanillin‐based phthalonitrile resin","authors":"Matthew Laskoski, Loren C. Brown, Andrew T. Kerr","doi":"10.1002/pol.20240187","DOIUrl":"https://doi.org/10.1002/pol.20240187","url":null,"abstract":"The renewable and biosynthetic molecule, vanillin, was used in the preparation of a new phthalonitrile resin (PN), containing two phthalonitrile groups without pre‐modification of the vanillin structure. This PN resin was characterized thoroughly by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), nuclear magnetic resonance (NMR) spectroscopy, rheometry, Fourier transform infrared spectroscopy (FTIR), and single‐crystal X‐ray diffraction (XRD). The monomer exhibited excellent rheometric viscosities below 250 cP at processing temperatures and a good pot life. After complete curing, the PN polymer exhibited thermal stability above 500°C, a glass transition temperature (<jats:italic>T</jats:italic><jats:sub>g</jats:sub>) above the final postcure temperature of 380°C, and exceptional retention of structural integrity. These results highlight a vanillin‐derived PN resin is an excellent candidate for a variety of applications where high temperature and mechanical stability over a large temperature range are required.","PeriodicalId":16888,"journal":{"name":"Journal of Polymer Science","volume":"11 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142261883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Arumugam Gopalakrishnan, Manivannan Nandhagopal, Mathivanan Narayanasamy, Chickiyan Sivakumar, Mahalingam Vanjinathan, A. Sultan Nasar
A new AB2‐type blocked isocyanate monomer containing azo‐ester linkages and N,N′‐diethanol amine groups was successfully synthesized. Deblocking of this monomer in DMF resulted corresponding hyperbranched poly(azo‐ester)urethanes (HBPAEUs). These polymers were characterized by UV–visible spectroscopy, GPC, TGA, and DSC methods. The molecular weights (Mw) of the polymers were in the range of 5500–25,500 g/mol. The effect of reaction temperature on Mw was found significant. The polymers were found thermally stable up to 240 °C and showed Tg between 150 and 153 °C. These polymers absorbed UV light at 407 nm in THF solvent and also exhibited high absorption coefficients. The photo induced trans to cis isomerization of HBPAEU in THF was also studied and found λmax of cis form of the polymer was shifted to 526 nm, which suggested that the stability of this isomer was good. And, the polymer showed aggregation induced enhanced emission. In addition, the monomer and HBPAEU were found to exhibit maximal antibacterial activity against various Gram‐positive and Gram‐negative bacteria. In‐vitro bio‐imaging studies of this monomer and polymer were carried out in onion epidermal and fungal cells and the results revealed that the polymer was more efficient for staining and imaging plant cells.
{"title":"Photoactive hyperbranched poly(azo‐ester) urethanes as fluorescent staining agent for plant cells","authors":"Arumugam Gopalakrishnan, Manivannan Nandhagopal, Mathivanan Narayanasamy, Chickiyan Sivakumar, Mahalingam Vanjinathan, A. Sultan Nasar","doi":"10.1002/pol.20240496","DOIUrl":"https://doi.org/10.1002/pol.20240496","url":null,"abstract":"A new AB<jats:sub>2</jats:sub>‐type blocked isocyanate monomer containing azo‐ester linkages and N,N′‐diethanol amine groups was successfully synthesized. Deblocking of this monomer in DMF resulted corresponding hyperbranched poly(azo‐ester)urethanes (HBPAEUs). These polymers were characterized by UV–visible spectroscopy, GPC, TGA, and DSC methods. The molecular weights (<jats:italic>M</jats:italic><jats:sub>w</jats:sub>) of the polymers were in the range of 5500–25,500 g/mol. The effect of reaction temperature on <jats:italic>M</jats:italic><jats:sub>w</jats:sub> was found significant. The polymers were found thermally stable up to 240 °C and showed <jats:italic>T</jats:italic><jats:sub>g</jats:sub> between 150 and 153 °C. These polymers absorbed UV light at 407 nm in THF solvent and also exhibited high absorption coefficients. The photo induced <jats:italic>trans</jats:italic> to <jats:italic>cis</jats:italic> isomerization of HBPAEU in THF was also studied and found <jats:italic>λ</jats:italic><jats:sub>max</jats:sub> of <jats:italic>cis</jats:italic> form of the polymer was shifted to 526 nm, which suggested that the stability of this isomer was good. And, the polymer showed aggregation induced enhanced emission. In addition, the monomer and HBPAEU were found to exhibit maximal antibacterial activity against various Gram‐positive and Gram‐negative bacteria. In‐vitro bio‐imaging studies of this monomer and polymer were carried out in onion epidermal and fungal cells and the results revealed that the polymer was more efficient for staining and imaging plant cells.","PeriodicalId":16888,"journal":{"name":"Journal of Polymer Science","volume":"19 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142261880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jingwen Yao, Jiaying Tong, Dan Zhao, Dong Chen, Yuhong Ma, Wantai Yang
The reversible addition‐fragment chain transfer (RAFT) alternating copolymerization of 2‐hydroxyethyl vinyl ether (HEVE) and dimethyl maleate (DMM) is achieved with S‐(cyanomethyl) O‐ethyl carbonodithioate (CMX) as medaitor and 2,2′‐azobis(2‐methylpropionitrile) (AIBN) as radical initiator. The effects of monomer concentrations, comonomer feeding ratios, molar ratio of monomer to CMX and solvent on the copolymerization and copolymer structure are systematically investigated. The living feature of the HEVE and DMM copolymerization is demonstrated by the linear increasement of the molecular weights with the monomer conversions, and relatively narrow molecular weight distributions of the copolymers. With dimethyl carbonate as solvent, poly(HEVE‐alt‐DMM) with Mn = 5200 and Mw/Mn = 1.34 are synthesized at [HEVE]/[DMM]/[CMX]/[AIBN] = 100/100/3/1. The alternating structure of the copolymer is demonstrated by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS) and proton nuclear magnetic resonance spectroscopy (1H NMR). The both α, ω‐end groups are mainly originated from the moiety of CMX. To further demonstrate the living feature of the alternating copolymerization, chain extension and block copolymerization are also carried out. With poly(HEVE‐alt‐DMM) as macro‐CTA (Mn = 5200, Mw/Mn = 1.34), the chain‐extension reaction has been successfully realized (Mn = 9600, Mw/Mn = 1.70), and the block copolymer with vinyl neonanoate as monomer also successfully synthesized (Mn = 9800, Mw/Mn = 1.42).
{"title":"RAFT polymerization of 2‐hydroxyethyl vinyl ether and dimethyl maleate","authors":"Jingwen Yao, Jiaying Tong, Dan Zhao, Dong Chen, Yuhong Ma, Wantai Yang","doi":"10.1002/pol.20240534","DOIUrl":"https://doi.org/10.1002/pol.20240534","url":null,"abstract":"The reversible addition‐fragment chain transfer (RAFT) alternating copolymerization of 2‐hydroxyethyl vinyl ether (HEVE) and dimethyl maleate (DMM) is achieved with <jats:italic>S</jats:italic>‐(cyanomethyl) <jats:italic>O</jats:italic>‐ethyl carbonodithioate (CMX) as medaitor and 2,2′‐azobis(2‐methylpropionitrile) (AIBN) as radical initiator. The effects of monomer concentrations, comonomer feeding ratios, molar ratio of monomer to CMX and solvent on the copolymerization and copolymer structure are systematically investigated. The living feature of the HEVE and DMM copolymerization is demonstrated by the linear increasement of the molecular weights with the monomer conversions, and relatively narrow molecular weight distributions of the copolymers. With dimethyl carbonate as solvent, poly(HEVE‐<jats:italic>alt</jats:italic>‐DMM) with <jats:italic>M</jats:italic><jats:sub>n</jats:sub> = 5200 and <jats:italic>M</jats:italic><jats:sub>w</jats:sub>/<jats:italic>M</jats:italic><jats:sub>n</jats:sub> = 1.34 are synthesized at [HEVE]/[DMM]/[CMX]/[AIBN] = 100/100/3/1. The alternating structure of the copolymer is demonstrated by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS) and proton nuclear magnetic resonance spectroscopy (<jats:sup>1</jats:sup>H NMR). The both α, ω‐end groups are mainly originated from the moiety of CMX. To further demonstrate the living feature of the alternating copolymerization, chain extension and block copolymerization are also carried out. With poly(HEVE‐<jats:italic>alt</jats:italic>‐DMM) as macro‐CTA (<jats:italic>M</jats:italic><jats:sub>n</jats:sub> = 5200, <jats:italic>M</jats:italic><jats:sub>w</jats:sub>/<jats:italic>M</jats:italic><jats:sub>n</jats:sub> = 1.34), the chain‐extension reaction has been successfully realized (<jats:italic>M</jats:italic><jats:sub>n</jats:sub> = 9600, <jats:italic>M</jats:italic><jats:sub>w</jats:sub>/<jats:italic>M</jats:italic><jats:sub>n</jats:sub> = 1.70), and the block copolymer with vinyl neonanoate as monomer also successfully synthesized (<jats:italic>M</jats:italic><jats:sub>n</jats:sub> = 9800, <jats:italic>M</jats:italic><jats:sub>w</jats:sub>/<jats:italic>M</jats:italic><jats:sub>n</jats:sub> = 1.42).","PeriodicalId":16888,"journal":{"name":"Journal of Polymer Science","volume":"92 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177486","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chengyao Zhuge, Yaping Wang, Qian Qian, Shunyang Li, Wangyang Lu, Nan Li
Hydrogel‐based flexible strain sensors have an enormous potential for applications in wearable electronics, but currently, realizing excellent mechanical properties and electrical conductivity of sensors is difficult. In this work, polyvinyl alcohol (PVA) hydrogels were augmented with positively charged silk nanofibers (PCSNF) and PEDOT:PSS, and the resultant PVA‐PEDOT:PSS‐PCSNF hydrogel fabric showed remarkable mechanical properties (4.38 MPa) and elevated electrical conductivity. The presence of ethylene glycol (EG) in the hydrogel fabric imparts antifreezing properties and sustains electrical conductivity even at frigid temperatures (−18°C). In addition, EG contributes to the improvement of the electrical conductivity of PEDOT:PSS. This PVA‐PEDOT:PSS‐PCSNF hydrogel fabric can be used as a precise and reliable strain sensor for detecting diverse human motions and facial expressions. Significantly, the PVA‐PEDOT:PSS‐PCSNF hydrogel fabric strain sensor exhibits a gauge factor of 1.02 and exceptional durability, withstanding 400 elbow bends. This study introduces an innovative method for creating high‐performance and resilient hydrogel‐based flexible sensors.
{"title":"High‐strength antifreezing flexible conductive polyvinyl alcohol hydrogel sensors co‐reinforced with silk porous mesh fabric and silk nanofibers","authors":"Chengyao Zhuge, Yaping Wang, Qian Qian, Shunyang Li, Wangyang Lu, Nan Li","doi":"10.1002/pol.20240494","DOIUrl":"https://doi.org/10.1002/pol.20240494","url":null,"abstract":"Hydrogel‐based flexible strain sensors have an enormous potential for applications in wearable electronics, but currently, realizing excellent mechanical properties and electrical conductivity of sensors is difficult. In this work, polyvinyl alcohol (PVA) hydrogels were augmented with positively charged silk nanofibers (PCSNF) and PEDOT:PSS, and the resultant PVA‐PEDOT:PSS‐PCSNF hydrogel fabric showed remarkable mechanical properties (4.38 MPa) and elevated electrical conductivity. The presence of ethylene glycol (EG) in the hydrogel fabric imparts antifreezing properties and sustains electrical conductivity even at frigid temperatures (−18°C). In addition, EG contributes to the improvement of the electrical conductivity of PEDOT:PSS. This PVA‐PEDOT:PSS‐PCSNF hydrogel fabric can be used as a precise and reliable strain sensor for detecting diverse human motions and facial expressions. Significantly, the PVA‐PEDOT:PSS‐PCSNF hydrogel fabric strain sensor exhibits a gauge factor of 1.02 and exceptional durability, withstanding 400 elbow bends. This study introduces an innovative method for creating high‐performance and resilient hydrogel‐based flexible sensors.","PeriodicalId":16888,"journal":{"name":"Journal of Polymer Science","volume":"24 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177485","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study aims to investigate the dual effects of (3‐aminopropyl)triethoxysilane (APTES)‐grafted‐GO (A‐g‐GO), and titanium dioxide (TiO2) on the novel chitosan (CS) packaging nanocomposite films developed via the solution‐casting method. The chemical properties of GO and A‐g‐GO were assessed using FTIR and XRD. Subsequently, the chemical, structural, and physical attributes of all chitosan packaging nanocomposite films were analyzed through FTIR, XRD, TGA, DSC, AFM, water contact angle analysis, and food packaging tests. Successful silanization of GO by APTES was first confirmed. The highest surface roughness value was observed in the CS/A‐g‐GO/TiO2 film (16.574 nm) compared to pristine CS and other nanocomposite films. Incorporating GO into the CS matrix improved its thermal stability, suggesting robust bonding between GO and the polymer matrix. The addition of A‐g‐GO slightly decreased the contact angle value (107.7° for CS/A‐g‐GO), whereas TiO2 increased contact angles (117.3° for CS/GO/TiO2 and 119.4° for CS/A‐g‐GO/TiO2), suggesting a more hydrophilic structure with GO and A‐g‐GO and a more hydrophobic structure with TiO2. Bread samples showed no structural distortion over 40 days. Therefore, the dual impacts of A‐g‐GO and TiO2 on the pristine CS film imply that the resulting CS/A‐g‐GO/TiO2 film exhibits potential as an exceptionally efficient packaging material for prolonging the freshness of bread.
本研究旨在探讨（3-氨丙基）三乙氧基硅烷（APTES）接枝-GO（A-g-GO）和二氧化钛（TiO2）对通过溶液浇铸法开发的新型壳聚糖（CS）包装纳米复合膜的双重影响。利用傅立叶变换红外光谱和 XRD 评估了 GO 和 A-g-GO 的化学特性。随后，通过傅立叶变换红外光谱、X射线衍射、热重分析、DSC、原子力显微镜、水接触角分析和食品包装测试，分析了所有壳聚糖包装纳米复合膜的化学、结构和物理属性。首先确认了 APTES 对 GO 的成功硅烷化。与原始 CS 和其他纳米复合膜相比，CS/A-g-GO/TiO2 膜的表面粗糙度值最高（16.574 nm）。在 CS 基体中加入 GO 提高了其热稳定性，这表明 GO 与聚合物基体之间的结合力很强。A-g-GO 的加入略微降低了接触角值（CS/A-g-GO 为 107.7°），而 TiO2 则增加了接触角（CS/GO/TiO2 为 117.3°，CS/A-g-GO/TiO2 为 119.4°），这表明 GO 和 A-g-GO 具有更亲水的结构，而 TiO2 具有更疏水的结构。面包样品在 40 天内没有出现结构变形。因此，A-g-GO 和 TiO2 对原始 CS 薄膜的双重影响表明，由此产生的 CS/A-g-GO/TiO2 薄膜具有作为一种特别有效的包装材料的潜力，可延长面包的新鲜度。
{"title":"Effects of graphene oxide and silane‐grafted graphene oxide on chitosan packaging nanocomposite films for bread preservation","authors":"Ş. Melda Eskitoros‐Togay","doi":"10.1002/pol.20240573","DOIUrl":"https://doi.org/10.1002/pol.20240573","url":null,"abstract":"This study aims to investigate the dual effects of (3‐aminopropyl)triethoxysilane (APTES)‐grafted‐GO (A‐g‐GO), and titanium dioxide (TiO<jats:sub>2</jats:sub>) on the novel chitosan (CS) packaging nanocomposite films developed via the solution‐casting method. The chemical properties of GO and A‐g‐GO were assessed using FTIR and XRD. Subsequently, the chemical, structural, and physical attributes of all chitosan packaging nanocomposite films were analyzed through FTIR, XRD, TGA, DSC, AFM, water contact angle analysis, and food packaging tests. Successful silanization of GO by APTES was first confirmed. The highest surface roughness value was observed in the CS/A‐g‐GO/TiO<jats:sub>2</jats:sub> film (16.574 nm) compared to pristine CS and other nanocomposite films. Incorporating GO into the CS matrix improved its thermal stability, suggesting robust bonding between GO and the polymer matrix. The addition of A‐g‐GO slightly decreased the contact angle value (107.7° for CS/A‐g‐GO), whereas TiO<jats:sub>2</jats:sub> increased contact angles (117.3° for CS/GO/TiO<jats:sub>2</jats:sub> and 119.4° for CS/A‐g‐GO/TiO<jats:sub>2</jats:sub>), suggesting a more hydrophilic structure with GO and A‐g‐GO and a more hydrophobic structure with TiO<jats:sub>2</jats:sub>. Bread samples showed no structural distortion over 40 days. Therefore, the dual impacts of A‐g‐GO and TiO<jats:sub>2</jats:sub> on the pristine CS film imply that the resulting CS/A‐g‐GO/TiO<jats:sub>2</jats:sub> film exhibits potential as an exceptionally efficient packaging material for prolonging the freshness of bread.","PeriodicalId":16888,"journal":{"name":"Journal of Polymer Science","volume":"1 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177487","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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