Pub Date : 2024-11-12DOI: 10.1016/j.polymer.2024.127842
Jie Liu, Xiaoqian Guo, Rongyang Zhai, Peng Sun, Jianyun Ding, Zhaoyang Wei, Weiwei Lei, Dean Shi
Disulfide bond has unique advantages in the preparation of recyclable rubbers since it not only shows similar sulfur structure to the crosslinks of traditional sulfide rubber systems but also can rearrange and exchange itself under mild external conditions. However, the reported disulfide bond-crosslinked rubbers often exhibit weak tensile strength or poor elongation because of the inappropriate disulfide bond content. Although some disulfide bond incorporated dual-crosslinked rubbers can combine good tensile strength with high elongation, the dual-crosslinked design always requires multi-step chemical modification in the solvent, which is complex and difficult for industrial operation. In this work, aromatic disulfide bonds are introduced into epoxidized natural rubber (ENR) as the vulcanizing agent by a simple one-step method. It is found that the elongation of rubbers can be more than 1100% with the tensile strength up to 7MPa when 2.1 phr of 2,2’-dithiosalicylic acid is added. The quantitative relationship between the content of aromatic disulfide bonds and the mechanical properties of ENR is systematically studied, as well as the exchangeable behaviors of disulfide bonds. The research results of this work will not only provide a facile route for preparing rubbers with easily industrial operation and high stretchability, but also contribute to the in-depth understanding of the mechanism of disulfide bonds.
{"title":"A highly stretchable disulfide-crosslinked epoxidized natural rubber by one-step method","authors":"Jie Liu, Xiaoqian Guo, Rongyang Zhai, Peng Sun, Jianyun Ding, Zhaoyang Wei, Weiwei Lei, Dean Shi","doi":"10.1016/j.polymer.2024.127842","DOIUrl":"https://doi.org/10.1016/j.polymer.2024.127842","url":null,"abstract":"Disulfide bond has unique advantages in the preparation of recyclable rubbers since it not only shows similar sulfur structure to the crosslinks of traditional sulfide rubber systems but also can rearrange and exchange itself under mild external conditions. However, the reported disulfide bond-crosslinked rubbers often exhibit weak tensile strength or poor elongation because of the inappropriate disulfide bond content. Although some disulfide bond incorporated dual-crosslinked rubbers can combine good tensile strength with high elongation, the dual-crosslinked design always requires multi-step chemical modification in the solvent, which is complex and difficult for industrial operation. In this work, aromatic disulfide bonds are introduced into epoxidized natural rubber (ENR) as the vulcanizing agent by a simple one-step method. It is found that the elongation of rubbers can be more than 1100% with the tensile strength up to 7MPa when 2.1 phr of 2,2’-dithiosalicylic acid is added. The quantitative relationship between the content of aromatic disulfide bonds and the mechanical properties of ENR is systematically studied, as well as the exchangeable behaviors of disulfide bonds. The research results of this work will not only provide a facile route for preparing rubbers with easily industrial operation and high stretchability, but also contribute to the in-depth understanding of the mechanism of disulfide bonds.","PeriodicalId":405,"journal":{"name":"Polymer","volume":"6 1","pages":""},"PeriodicalIF":4.6,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142601636","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-12DOI: 10.1016/j.polymer.2024.127804
Yan Chen , Xiaoyu Yin , Yang Wei , Zelong Xu , Xiaohua Ma , Xiangyang Liu , Xu Wang
The macromolecular chain of conventional polyimide (PI) is a predominant linear extension, which is anticipated to uphold robust interchain interactions essential for preserving overall mechanical and thermal performance. This study is dedicated to the design and synthesis for the novel PIs containing folded chains, with a particular emphasis on modifying the chain conformational behavior with respect to the structure of the aggregation state and the corresponding gas separation properties. First, two unidirectional diamine monomers, dibenzo [c, g] phenanthrene-9,12-diamine (NPDA) and anthracene-1,8-diamine (ADA), were meticulously synthesized through a sequence of chemical reactions, including Witting olefination and photocyclization. These monomers possess distinctive spatial characteristics: NPDA adopts a helical conformation, while ADA maintains a planar structure. Subsequently, the corresponding folded chain-containing PIs, denoted as NPI and API, were successfully achieved by copolymerizing one of the unidirectional monomers with the 6FDA-TPDA system. API and NPI generally exhibit a propensity for enhanced molecular chain stacking, while retaining their good solubility and processability. Drawing from both experimental data and simulation results, it was ascertained that the inclusion of these two monomers produces a rearrangement of pore sizes with a decrease in large-size micropores and an increase in the percentage of ultra-micropores. Moreover, the PI membranes with the folded fragments have a much better CO2 plasticization resistance.
传统聚酰亚胺（PI）的大分子链主要是线性延伸，这对保持整体机械和热性能至关重要。本研究致力于设计和合成含有折叠链的新型聚酰亚胺，特别强调在聚合态结构和相应的气体分离性能方面改变链的构象行为。首先，通过一系列化学反应（包括 Witting 烯化和光环化）精心合成了两种单向二胺单体，即二苯并 [c, g] 菲-9,12-二胺（NPDA）和蒽-1,8-二胺（ADA）。这些单体具有独特的空间特性：NPDA 采用螺旋构象，而 ADA 则保持平面结构。随后，通过将其中一种单向单体与 6FDA-TPDA 系统共聚，成功制备出了相应的含折叠链的 PI，分别称为 NPI 和 API。API 和 NPI 在保持良好的溶解性和加工性的同时，还普遍表现出增强分子链堆叠的倾向。根据实验数据和模拟结果可以确定，加入这两种单体后，孔径大小发生了重新排列，大尺寸微孔减少，超微孔比例增加。此外，含有折叠片段的 PI 膜具有更好的抗二氧化碳塑化性能。
{"title":"Synthesis and characterization of polyimides with rigid folded fragments","authors":"Yan Chen , Xiaoyu Yin , Yang Wei , Zelong Xu , Xiaohua Ma , Xiangyang Liu , Xu Wang","doi":"10.1016/j.polymer.2024.127804","DOIUrl":"10.1016/j.polymer.2024.127804","url":null,"abstract":"<div><div>The macromolecular chain of conventional polyimide (PI) is a predominant linear extension, which is anticipated to uphold robust interchain interactions essential for preserving overall mechanical and thermal performance. This study is dedicated to the design and synthesis for the novel PIs containing folded chains, with a particular emphasis on modifying the chain conformational behavior with respect to the structure of the aggregation state and the corresponding gas separation properties. First, two unidirectional diamine monomers, dibenzo [c, g] phenanthrene-9,12-diamine (NPDA) and anthracene-1,8-diamine (ADA), were meticulously synthesized through a sequence of chemical reactions, including Witting olefination and photocyclization. These monomers possess distinctive spatial characteristics: NPDA adopts a helical conformation, while ADA maintains a planar structure. Subsequently, the corresponding folded chain-containing PIs, denoted as NPI and API, were successfully achieved by copolymerizing one of the unidirectional monomers with the 6FDA-TPDA system. API and NPI generally exhibit a propensity for enhanced molecular chain stacking, while retaining their good solubility and processability. Drawing from both experimental data and simulation results, it was ascertained that the inclusion of these two monomers produces a rearrangement of pore sizes with a decrease in large-size micropores and an increase in the percentage of ultra-micropores. Moreover, the PI membranes with the folded fragments have a much better CO<sub>2</sub> plasticization resistance.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"315 ","pages":"Article 127804"},"PeriodicalIF":4.1,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142601632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The gel time of functional hydrogels is an essential property that dictates their utility in various applications. To accurately assess this parameter, the chitosan-glutaraldehyde hydrogels were characterized here using two complementary analytical tools, rotational rheometer, and diffusing wave spectrometer (DWS). Rotational rheometers are widely used to continuously monitor the macro-mechanical properties of hydrogels during the gelation process. By observing the modulus change curve, one can gain insights into the instantaneous changes occurring within the gel network. This method provides a direct measurement of the gel's mechanical strength; however, it involves applying external forces to the sample, which may introduce artifacts such as measurement lag and potential sample deformation or destruction. Results of this study indicated that the application of external force during rotary rheometer measurements disrupted the gelation process. In contrast, DWS detected alterations in the microstructure by measuring light diffusion, allowing to track microstructural changes post-crosslinking, and curing without the interference of external stress. Thus, DWS offers a non-invasive approach to studying gelation as it detected the Brownian motion of particles within the hydrogel by monitoring the diffraction of light, thereby providing undisturbed dynamic information about the gel's behavior. The DWS technique is particularly useful for tracking microstructural changes that occur during hydrogel crosslinking and curing, without altering the gel's native state. An additional advantage of DWS is its ability to investigate the pH effect on gelation. By measuring changes in gelation time as a function of pH, we could achieve precise control over the gelation process. This fine-tuning of gelation kinetics is crucial for applications that require rapid or delayed gelation, offering a level of precision that is difficult to match with traditional rheological methods.
{"title":"Investigating the pH-Dependence of Gelation process in Chitosan-glutaraldehyde Hydrogels with Diffusing Wave Spectroscopy","authors":"Xiaoqiang Xue, Xuepei Miao, Jian Liu, Yi Ding, Yuheng Zhang, Yunkai Sun, Wenyan Huang, Qimin Jiang, Bibiao Jiang, Sridhar Komarneni","doi":"10.1016/j.polymer.2024.127827","DOIUrl":"https://doi.org/10.1016/j.polymer.2024.127827","url":null,"abstract":"The gel time of functional hydrogels is an essential property that dictates their utility in various applications. To accurately assess this parameter, the chitosan-glutaraldehyde hydrogels were characterized here using two complementary analytical tools, rotational rheometer, and diffusing wave spectrometer (DWS). Rotational rheometers are widely used to continuously monitor the macro-mechanical properties of hydrogels during the gelation process. By observing the modulus change curve, one can gain insights into the instantaneous changes occurring within the gel network. This method provides a direct measurement of the gel's mechanical strength; however, it involves applying external forces to the sample, which may introduce artifacts such as measurement lag and potential sample deformation or destruction. Results of this study indicated that the application of external force during rotary rheometer measurements disrupted the gelation process. In contrast, DWS detected alterations in the microstructure by measuring light diffusion, allowing to track microstructural changes post-crosslinking, and curing without the interference of external stress. Thus, DWS offers a non-invasive approach to studying gelation as it detected the Brownian motion of particles within the hydrogel by monitoring the diffraction of light, thereby providing undisturbed dynamic information about the gel's behavior. The DWS technique is particularly useful for tracking microstructural changes that occur during hydrogel crosslinking and curing, without altering the gel's native state. An additional advantage of DWS is its ability to investigate the pH effect on gelation. By measuring changes in gelation time as a function of pH, we could achieve precise control over the gelation process. This fine-tuning of gelation kinetics is crucial for applications that require rapid or delayed gelation, offering a level of precision that is difficult to match with traditional rheological methods.","PeriodicalId":405,"journal":{"name":"Polymer","volume":"196 1","pages":""},"PeriodicalIF":4.6,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142601630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-12DOI: 10.1016/j.polymer.2024.127821
Caizhao Liu , Shuaijie Li , Zhigang Yuan , Shuangle Xue , Mingming Sun , Xugang Zhang , Jianhui Li , Gang Xue , Xuefeng Bai , Wenbin Liu , Bin Zhang
Phthalonitrile (PN) resins are highly valued in high-performance applications due to their exceptional thermal stability and mechanical properties. However, traditional PN monomers suffer from high melting points and slow curing rates, often requiring external curing accelerators that can compromise thermal performance. This study focuses on the synthesis and characterization of novel low-melting maleimide-containing PN monomers designed to enhance curing efficiency and thermal properties. Maleimide groups were introduced to improve self-catalytic properties, facilitating a more efficient curing process. The polymerization behavior, thermal stability, adhesive, and mechanical properties of these compounds were thoroughly investigated. Differential Scanning Calorimetry (DSC) and rheological tests showed that incorporating alkyl groups significantly improved flow properties, facilitating easier processing. The difference in the three-dimensional network structures of the cured PN resins was confirmed by Fourier Transform Infrared (FT-IR) spectroscopy. Thermogravimetric Analysis (TGA) demonstrated outstanding thermal stability, with 5 % weight loss temperatures ranging from 387 °C to 418 °C under air and from 420 °C to 471 °C under nitrogen. Dynamic Mechanical Analysis (DMA) confirmed high glass transition temperatures (Tg) exceeding 400 °C, indicating superior thermal performance and making these resins suitable for advanced applications in harsh environments. These findings suggest that low-melting maleimide-containing PN systems are promising candidates for high-performance materials in aerospace, electronics, and other demanding fields.
{"title":"Low-melting maleimide-containing phthalonitrile resins: Synthesis, curing behavior, and thermal performance","authors":"Caizhao Liu , Shuaijie Li , Zhigang Yuan , Shuangle Xue , Mingming Sun , Xugang Zhang , Jianhui Li , Gang Xue , Xuefeng Bai , Wenbin Liu , Bin Zhang","doi":"10.1016/j.polymer.2024.127821","DOIUrl":"10.1016/j.polymer.2024.127821","url":null,"abstract":"<div><div>Phthalonitrile (PN) resins are highly valued in high-performance applications due to their exceptional thermal stability and mechanical properties. However, traditional PN monomers suffer from high melting points and slow curing rates, often requiring external curing accelerators that can compromise thermal performance. This study focuses on the synthesis and characterization of novel low-melting maleimide-containing PN monomers designed to enhance curing efficiency and thermal properties. Maleimide groups were introduced to improve self-catalytic properties, facilitating a more efficient curing process. The polymerization behavior, thermal stability, adhesive, and mechanical properties of these compounds were thoroughly investigated. Differential Scanning Calorimetry (DSC) and rheological tests showed that incorporating alkyl groups significantly improved flow properties, facilitating easier processing. The difference in the three-dimensional network structures of the cured PN resins was confirmed by Fourier Transform Infrared (FT-IR) spectroscopy. Thermogravimetric Analysis (TGA) demonstrated outstanding thermal stability, with 5 % weight loss temperatures ranging from 387 °C to 418 °C under air and from 420 °C to 471 °C under nitrogen. Dynamic Mechanical Analysis (DMA) confirmed high glass transition temperatures (<em>Tg</em>) exceeding 400 °C, indicating superior thermal performance and making these resins suitable for advanced applications in harsh environments. These findings suggest that low-melting maleimide-containing PN systems are promising candidates for high-performance materials in aerospace, electronics, and other demanding fields.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"315 ","pages":"Article 127821"},"PeriodicalIF":4.1,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142601633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-12DOI: 10.1016/j.polymer.2024.127825
Xiaoqin Cao, Yujun Feng, Hongyao Yin
We report a novel multicomponent initiators-based copolymerization strategy for synthesizing of acrylamide (AM) and 2-acrylamide-2-methylpropane sulfonic acid (AMPS) copolymers, denoted by P(AM-co-AMPS), with an ultra-high content of AMPS (≥50 mol%) and an ultra-high molecular weight (>107 g/mol), while achieving a high conversion rate of monomer (∼100.0 %). The multicomponent initiators contain a redox couple, an azo compound, and a catalyst. Our investigation into the mechanism suggested that the synergistic effect in different rate constant for initiator decomposition between redox and azo initiators was responsible for actualizing ultra-high molecular weight copolymers with high conversion rates of monomer. Moreover, copolymers with 75 mol% and 100 mol% of AMPS were synthesized to verify the advantage of the multicomponent initiators-based strategy, both of which exhibited ultra-high molecular weights and ultra-high monomer conversion rates. This study fills a long-standing gap in research on the polyacrylamide family by providing highly functionalized P(AM-co-AMPS) with an ultra-high molecular weight. Moreover, it reveals how multicomponent initiators reconcile the contradiction between the ultra-high molecular weight and the high conversion rate in copolymerization.
{"title":"Facile access to highly functionalized polyacrylamide with ultra-high molecular weight: Multicomponent initiators-based free radical polymerization","authors":"Xiaoqin Cao, Yujun Feng, Hongyao Yin","doi":"10.1016/j.polymer.2024.127825","DOIUrl":"10.1016/j.polymer.2024.127825","url":null,"abstract":"<div><div>We report a novel multicomponent initiators-based copolymerization strategy for synthesizing of acrylamide (AM) and 2-acrylamide-2-methylpropane sulfonic acid (AMPS) copolymers, denoted by P(AM-<em>co</em>-AMPS), with an ultra-high content of AMPS (≥50 mol%) and an ultra-high molecular weight (>10<sup>7</sup> g/mol), while achieving a high conversion rate of monomer (∼100.0 %). The multicomponent initiators contain a redox couple, an azo compound, and a catalyst. Our investigation into the mechanism suggested that the synergistic effect in different rate constant for initiator decomposition between redox and azo initiators was responsible for actualizing ultra-high molecular weight copolymers with high conversion rates of monomer. Moreover, copolymers with 75 mol% and 100 mol% of AMPS were synthesized to verify the advantage of the multicomponent initiators-based strategy, both of which exhibited ultra-high molecular weights and ultra-high monomer conversion rates. This study fills a long-standing gap in research on the polyacrylamide family by providing highly functionalized P(AM-<em>co</em>-AMPS) with an ultra-high molecular weight. Moreover, it reveals how multicomponent initiators reconcile the contradiction between the ultra-high molecular weight and the high conversion rate in copolymerization.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"315 ","pages":"Article 127825"},"PeriodicalIF":4.1,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142601634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-12DOI: 10.1016/j.polymer.2024.127829
Baiqing Yu, Yanling Xu, Jianliang Nie, Dingfan Li, Zijuan Su, Zhi Huang, Xiaocan Zhang, Weibin Wu, Hai Li, Wuyi Zhou, Wenxu Zheng
In this paper, a novel polyacrylonitrile (PAN)/collagen (CO)/tannic acid (TA) composite nanofiber membrane for the adsorption of Cu(II) in water was prepared. The nanofibrous membranes were characterized by Fourier transform infrared (FTIR), scanning electron microscopy (SEM), thermogravimetric (TG), and water contact angle (WCA) techniques, and their adsorption performance on Cu(II) in water was tested. The results showed that incorporating CO improved the hydrophilic performance of the membranes, and the contact angle of PAN/CO decreased from 60.57° to 39.16° with the increase of CO content, which exhibited good hydrophilicity. Moreover, CO effectively crosslinked TA, so that TA was well fixed on the surface of the fiber membrane, and the resulting PAN/CO/TA composite nanofiber membrane had good fiber morphology, uniform fiber diameter distribution, with an average diameter of 292.22 nm, and good adsorption performance for Cu(II), up to 133.26 mg/g. The adsorption kinetics fitting showed that the adsorption mechanism was mainly electrostatic adsorption and chelation of Cu(II) by phenoxy anion. PAN/CO/TA and PAN/CO/TA/Cu nanofiber membranes showed bacteriostatic effects on E. coli and S. aureus, with PAN/CO/TA/Cu nanofiber membranes being particularly effective, with the average inhibition bands for E. coli and S. aureus being 7.50 mm and 10.05 mm, respectively. The distribution of the electric field during the spinning process was also simulated by finite element analysis in this study. Since TA is a natural polymer of plant origin and CO is of animal origin, it provides an environmentally friendly and cost-effective method to remove Cu(II) from water.
本文制备了一种新型聚丙烯腈（PAN）/胶原蛋白（CO）/单宁酸（TA）复合纳米纤维膜，用于吸附水中的铜（II）。通过傅立叶变换红外（FTIR）、扫描电子显微镜（SEM）、热重（TG）和水接触角（WCA）技术对纳米纤维膜进行了表征，并测试了它们对水中 Cu（II）的吸附性能。结果表明，CO 的加入提高了膜的亲水性能，随着 CO 含量的增加，PAN/CO 的接触角从 60.57°降至 39.16°，表现出良好的亲水性。此外，CO 能有效交联 TA，使 TA 很好地固定在纤维膜表面，得到的 PAN/CO/TA 复合纳米纤维膜具有良好的纤维形貌，纤维直径分布均匀，平均直径为 292.22 nm，对 Cu(II) 的吸附性能良好，最高可达 133.26 mg/g。吸附动力学拟合结果表明，吸附机理主要是静电吸附和苯氧基阴离子对 Cu（II）的螯合作用。PAN/CO/TA 和 PAN/CO/TA/Cu 纳米纤维膜对大肠杆菌和金黄色葡萄球菌有抑菌作用，其中 PAN/CO/TA/Cu 纳米纤维膜的抑菌效果尤为显著，对大肠杆菌和金黄色葡萄球菌的平均抑菌带分别为 7.50 mm 和 10.05 mm。本研究还通过有限元分析模拟了纺丝过程中的电场分布。由于 TA 是源于植物的天然聚合物，而 CO 是源于动物的天然聚合物，因此它为去除水中的 Cu（II）提供了一种环境友好且经济有效的方法。
{"title":"Electrospun hydrophilic PAN/CO/TA composite nanofibrous membrane for adsorbing Cu(II) in water","authors":"Baiqing Yu, Yanling Xu, Jianliang Nie, Dingfan Li, Zijuan Su, Zhi Huang, Xiaocan Zhang, Weibin Wu, Hai Li, Wuyi Zhou, Wenxu Zheng","doi":"10.1016/j.polymer.2024.127829","DOIUrl":"https://doi.org/10.1016/j.polymer.2024.127829","url":null,"abstract":"In this paper, a novel polyacrylonitrile (PAN)/collagen (CO)/tannic acid (TA) composite nanofiber membrane for the adsorption of Cu(II) in water was prepared. The nanofibrous membranes were characterized by Fourier transform infrared (FTIR), scanning electron microscopy (SEM), thermogravimetric (TG), and water contact angle (WCA) techniques, and their adsorption performance on Cu(II) in water was tested. The results showed that incorporating CO improved the hydrophilic performance of the membranes, and the contact angle of PAN/CO decreased from 60.57° to 39.16° with the increase of CO content, which exhibited good hydrophilicity. Moreover, CO effectively crosslinked TA, so that TA was well fixed on the surface of the fiber membrane, and the resulting PAN/CO/TA composite nanofiber membrane had good fiber morphology, uniform fiber diameter distribution, with an average diameter of 292.22 nm, and good adsorption performance for Cu(II), up to 133.26 mg/g. The adsorption kinetics fitting showed that the adsorption mechanism was mainly electrostatic adsorption and chelation of Cu(II) by phenoxy anion. PAN/CO/TA and PAN/CO/TA/Cu nanofiber membranes showed bacteriostatic effects on <em>E. coli</em> and <em>S. aureus</em>, with PAN/CO/TA/Cu nanofiber membranes being particularly effective, with the average inhibition bands for <em>E. coli</em> and <em>S. aureus</em> being 7.50 mm and 10.05 mm, respectively. The distribution of the electric field during the spinning process was also simulated by finite element analysis in this study. Since TA is a natural polymer of plant origin and CO is of animal origin, it provides an environmentally friendly and cost-effective method to remove Cu(II) from water.","PeriodicalId":405,"journal":{"name":"Polymer","volume":"158 1","pages":""},"PeriodicalIF":4.6,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142601637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-10DOI: 10.1016/j.polymer.2024.127789
Lu He , Jingxian Qin , Wanli Zhang , Weiwei Zhu , Jiang Li , Shaoyun Guo , Jiabin Shen
Membrane separation technology is a promising choice for treating oily water from industrial and domestic sewage. The elaborate design of pore structure can realize a good trade-off between separation flux and efficiency, thus taking the full advantages of membrane separation. Herein, polychlorotrifluoroethylene (PCTFE) microporous membrane with tunable pore structure was fabricated via a sacrificial template method. Fluoroelastomer (FR), serving as sacrificial template, was incorporated into PCTFE via a solvent-assisted method, forming PCTFE/FR blending films. After removing FR via solvent-dissolving, porous PCTFE membrane was obtained. More important, the gradual increment of FR loading made the morphology of PCTFE/FR blending films realize the transformation from “sea-island” to bicontinuous structure, thus endowing the membranes with tunable pore structure, surface wettability, as well as mechanical properties. Among the candidates, 50FR membranes possessed good flexibility, twist-resistance, as well as excellent creep-resistance and can efficiently separate oil from various water/oil mixtures. The oil (dichloromethane) permeability, separation efficiency, and filtrated oil purity were high up ∼10000 L/(m2⋅h), ∼99 %, and ∼99.92 wt%, respectively. Additionally, although undergoing 25 separation cycles or being immersed into various highly-corrosive liquid (including 1 M HCl, 1 M NaOH, DMF, ethanediamine, and concentrated HNO3) for 7 days, the properties of the membrane changed little. These features suggested a great potential for preparing PCTFE membranes used for oil/water separation in various harsh environment.
{"title":"PCTFE microporous membrane with high corrosion-resistance and ultra-fast oil/water separation performances","authors":"Lu He , Jingxian Qin , Wanli Zhang , Weiwei Zhu , Jiang Li , Shaoyun Guo , Jiabin Shen","doi":"10.1016/j.polymer.2024.127789","DOIUrl":"10.1016/j.polymer.2024.127789","url":null,"abstract":"<div><div>Membrane separation technology is a promising choice for treating oily water from industrial and domestic sewage. The elaborate design of pore structure can realize a good trade-off between separation flux and efficiency, thus taking the full advantages of membrane separation. Herein, polychlorotrifluoroethylene (PCTFE) microporous membrane with tunable pore structure was fabricated via a sacrificial template method. Fluoroelastomer (FR), serving as sacrificial template, was incorporated into PCTFE via a solvent-assisted method, forming PCTFE/FR blending films. After removing FR via solvent-dissolving, porous PCTFE membrane was obtained. More important, the gradual increment of FR loading made the morphology of PCTFE/FR blending films realize the transformation from “sea-island” to bicontinuous structure, thus endowing the membranes with tunable pore structure, surface wettability, as well as mechanical properties. Among the candidates, 50FR membranes possessed good flexibility, twist-resistance, as well as excellent creep-resistance and can efficiently separate oil from various water/oil mixtures. The oil (dichloromethane) permeability, separation efficiency, and filtrated oil purity were high up ∼10000 L/(m<sup>2</sup>⋅h), ∼99 %, and ∼99.92 wt%, respectively. Additionally, although undergoing 25 separation cycles or being immersed into various highly-corrosive liquid (including 1 M HCl, 1 M NaOH, DMF, ethanediamine, and concentrated HNO<sub>3</sub>) for 7 days, the properties of the membrane changed little. These features suggested a great potential for preparing PCTFE membranes used for oil/water separation in various harsh environment.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"315 ","pages":"Article 127789"},"PeriodicalIF":4.1,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142597517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We report herein that the catalytic system composed of a bis(benzimidazole)NiCl2 complex (1, bis(benzimidazole) = phenylbis(benzimidazol-2-yl)methane), Al(C8H17)3 (AlOct3), and [Ph3C][B(C6F5)4] mediates highly cis-1,4-specific (up to 95 %) polymerization of isoprene (IP). This is the first nickel complex-based catalyst system that achieved the cis-1,4-specific IP polymerization with a selectivity of more than 90 %. The effects of AlR3 (R = iBu, Et, Me), AlEt2Cl and activator ([PhNMe2H][B(C6F5)4], B(C6F5)3, MAO) on the polymerization behavior were also investigated. The 1/AlOct3/[Ph3C][B(C6F5)4] system also catalyzed the cis-1,4-specific polymerization of other 1,3-conjugated dienes such as 1,3-butadiene (BD), (E)-1,3-pentadiene (EPD) and β-myrcene (MY) (up to 92 % for BD, 84 % for EPD and 72 % for MY).
{"title":"Cis-1,4-specific polymerization of 1,3-conjugated dienes with bis(benzimidazole)NiCl2 catalyst system","authors":"Yasuyuki Ueda , Kakeru Tsukahara , Masahito Hasumi , Kohei Uyama , Hiroshi Yukawa , Takehito Kato , Tomoyuki Toda , Shun Ohta , Kei Nishii","doi":"10.1016/j.polymer.2024.127806","DOIUrl":"10.1016/j.polymer.2024.127806","url":null,"abstract":"<div><div>We report herein that the catalytic system composed of a bis(benzimidazole)NiCl<sub>2</sub> complex (<strong>1</strong>, bis(benzimidazole) = phenylbis(benzimidazol-2-yl)methane), Al(C<sub>8</sub>H<sub>17</sub>)<sub>3</sub> (AlOct<sub>3</sub>), and [Ph<sub>3</sub>C][B(C<sub>6</sub>F<sub>5</sub>)<sub>4</sub>] mediates highly <em>cis</em>-1,4-specific (up to 95 %) polymerization of isoprene (IP). This is the first nickel complex-based catalyst system that achieved the <em>cis</em>-1,4-specific IP polymerization with a selectivity of more than 90 %. The effects of AlR<sub>3</sub> (R = <sup><em>i</em></sup>Bu, Et, Me), AlEt<sub>2</sub>Cl and activator ([PhNMe<sub>2</sub>H][B(C<sub>6</sub>F<sub>5</sub>)<sub>4</sub>], B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub>, MAO) on the polymerization behavior were also investigated. The <strong>1</strong>/AlOct<sub>3</sub>/[Ph<sub>3</sub>C][B(C<sub>6</sub>F<sub>5</sub>)<sub>4</sub>] system also catalyzed the <em>cis</em>-1,4-specific polymerization of other 1,3-conjugated dienes such as 1,3-butadiene (BD), (<em>E</em>)-1,3-pentadiene (EPD) and <em>β</em>-myrcene (MY) (up to 92 % for BD, 84 % for EPD and 72 % for MY).</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"315 ","pages":"Article 127806"},"PeriodicalIF":4.1,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142597523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The synthesis of two conjugated polymers (P1 and P2) for supercapacitor application was reported. The materials were prepared using a condensation reaction between tetraphenylethene (TPE) with di-(TPE-2CHO) or tetra-carboxaldehyde (TPE-4CHO) derivatives and 1,5-diaminonaphthalene (1,5-DAN). The polymers were characterized using Fourier transforms infrared (FT-IR), solid-state 13C nuclear magnetic resonance (13C NMR), scanning electron microscopy (SEM), X-ray diffraction (XRD), and diffuse reflectance spectroscopy (DRS). P1 and P2 polymers displayed a spherical shape, with particle sizes of 6.8 ± 1 μm and 0.97 ± 0.1 μm, respectively. In addition, P1 and P2 exhibited wide light absorption (200–466 nm), accompanied by a relatively low bandgap of 2.3 eV and 2.4 eV for P1 and P2 respectively. Electrochemical investigations of P1 and P2 revealed redox behavior observed in the cyclic voltammetry (CV) curves suggesting a faradaic charge storage mechanism. At a scan rate of 1 mV/s, P1 and P2 demonstrated specific capacitances of 274.8 F/g and 207.9 F/g, respectively. The electrochemical performance of both polymers was further analyzed using galvanostatic charge-discharge (GCD), linear sweep voltammetry (LSV), and electrochemical impedance spectroscopy (EIS) using Nyquist plots. The observed decrease in charge transfer resistance for P1 and P2 can be ascribed to the conjugation within their chemical structures. The polymer can be recycled for 5000 cycles with <10 % loss of the polymer's efficiency.
{"title":"Conjugated tetraphenylethene-based polymers for supercapacitor","authors":"Abdelreheem Abdelfatah Saddik , Hani Nasser Abdelhamid","doi":"10.1016/j.polymer.2024.127778","DOIUrl":"10.1016/j.polymer.2024.127778","url":null,"abstract":"<div><div>The synthesis of two conjugated polymers (<strong>P1</strong> and <strong>P2</strong>) for supercapacitor application was reported. The materials were prepared using a condensation reaction between tetraphenylethene (<strong>TPE</strong>) with di-(<strong>TPE-2CHO</strong>) or tetra-carboxaldehyde (<strong>TPE-4CHO</strong>) derivatives and 1,5-diaminonaphthalene (<strong>1,5-DAN</strong>). The polymers were characterized using Fourier transforms infrared (FT-IR), solid-state <sup>13</sup>C nuclear magnetic resonance (<sup>13</sup>C NMR), scanning electron microscopy (SEM), X-ray diffraction (XRD), and diffuse reflectance spectroscopy (DRS). <strong>P1</strong> and <strong>P2</strong> polymers displayed a spherical shape, with particle sizes of 6.8 ± 1 μm and 0.97 ± 0.1 μm, respectively. In addition, <strong>P1</strong> and <strong>P2</strong> exhibited wide light absorption (200–466 nm), accompanied by a relatively low bandgap of 2.3 eV and 2.4 eV for P1 and P2 respectively. Electrochemical investigations of <strong>P1</strong> and <strong>P2</strong> revealed redox behavior observed in the cyclic voltammetry (CV) curves suggesting a faradaic charge storage mechanism. At a scan rate of 1 mV/s, <strong>P1</strong> and <strong>P2</strong> demonstrated specific capacitances of 274.8 F/g and 207.9 F/g, respectively. The electrochemical performance of both polymers was further analyzed using galvanostatic charge-discharge (GCD), linear sweep voltammetry (LSV), and electrochemical impedance spectroscopy (EIS) using Nyquist plots. The observed decrease in charge transfer resistance for <strong>P1</strong> and <strong>P2</strong> can be ascribed to the conjugation within their chemical structures. The polymer can be recycled for 5000 cycles with <10 % loss of the polymer's efficiency.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"315 ","pages":"Article 127778"},"PeriodicalIF":4.1,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142597518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-09DOI: 10.1016/j.polymer.2024.127800
Steffen M. Weidner , Felix Scheliga , Hans R. Kricheldorf
Two poly(L-lactide)s (PLAs) with a degree of polymerization (DP) of 20 or 100 were prepared by trifluoroethanol-initiated ring-opening polymerization (ROP) catalyzed by tin(II) 2-ethyl hexanoate (SnOct2). These PLAs were annealed at 140 °C or at 160 °C in the presence of SnOct2, and the changes in topology and molecular weight distribution (MWD) were monitored by matrix-assisted laser desorption/ionization time-of-flight (MALDI TOF) mass spectrometry and gel permeation chromatography (GPC). For the PLA with a DP 20, the main reaction was polycondensation combined with higher dispersities. In the case of the DP 100, PLA polycondensation was combined with disproportionation and the formation of a new MWD maximum around m/z 3500. In addition, extensive cyclization occurred, and the resulting cyclic PLAs crystallized separately from the linear chains in the form of extended ring crystals. These results also suggest that both extended chain and extended ring crystals posses the same crystal thickness as a result of thermodynamically controlled transesterification in the solid state.
{"title":"Polycondensation, cyclization and disproportionation of solid Poly(L-lactide) trifluoroethyl esters and the simultaneous formation of extended chain crystals and extended ring crystals","authors":"Steffen M. Weidner , Felix Scheliga , Hans R. Kricheldorf","doi":"10.1016/j.polymer.2024.127800","DOIUrl":"10.1016/j.polymer.2024.127800","url":null,"abstract":"<div><div>Two poly(L-lactide)s (PLAs) with a degree of polymerization (DP) of 20 or 100 were prepared by trifluoroethanol-initiated ring-opening polymerization (ROP) catalyzed by tin(II) 2-ethyl hexanoate (SnOct<sub>2</sub>). These PLAs were annealed at 140 °C or at 160 °C in the presence of SnOct<sub>2</sub>, and the changes in topology and molecular weight distribution (MWD) were monitored by matrix-assisted laser desorption/ionization time-of-flight (MALDI TOF) mass spectrometry and gel permeation chromatography (GPC). For the PLA with a DP 20, the main reaction was polycondensation combined with higher dispersities. In the case of the DP 100, PLA polycondensation was combined with disproportionation and the formation of a new MWD maximum around <em>m/z</em> 3500. In addition, extensive cyclization occurred, and the resulting cyclic PLAs crystallized separately from the linear chains in the form of extended ring crystals. These results also suggest that both extended chain and extended ring crystals posses the same crystal thickness as a result of thermodynamically controlled transesterification in the solid state.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"315 ","pages":"Article 127800"},"PeriodicalIF":4.1,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142597565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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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