Pub Date : 2024-09-18DOI: 10.1007/s10118-024-3194-5
Qi-Yuan Qiu, Yong-Jian Zhu, Zhong-Tao Wu, Liang Dai
Recent experimental observations of knotting in DNA and proteins have stimulated the simulation studies of polymer knots. Simulation studies usually identify knots in polymer conformations through the calculation of the Alexander polynomial. However, the Alexander polynomial cannot directly discriminate knot chirality, while knot chirality plays important roles in many physical, chemical, and biological properties. In this work, we discover a new relationship for knot chirality and accordingly, develop a new algorithm to extend the applicability of the Alexander polynomial to the identification of knot chirality. Our algorithm adds an extra step in the ordinary calculation of the Alexander polynomial. This extra step only slightly increases the computational cost. The correctness of our algorithm has been proved mathematically by us. The implication of this algorithm in physical research has been demonstrated by our studies of the tube model for polymer knots. Without this algorithm, we would be unable to obtain the tubes for polymer knots.
{"title":"A Simple and Efficient Algorithm to Identify the Chirality of Polymer Knots Based on the Alexander Polynomial","authors":"Qi-Yuan Qiu, Yong-Jian Zhu, Zhong-Tao Wu, Liang Dai","doi":"10.1007/s10118-024-3194-5","DOIUrl":"10.1007/s10118-024-3194-5","url":null,"abstract":"<div><p>Recent experimental observations of knotting in DNA and proteins have stimulated the simulation studies of polymer knots. Simulation studies usually identify knots in polymer conformations through the calculation of the Alexander polynomial. However, the Alexander polynomial cannot directly discriminate knot chirality, while knot chirality plays important roles in many physical, chemical, and biological properties. In this work, we discover a new relationship for knot chirality and accordingly, develop a new algorithm to extend the applicability of the Alexander polynomial to the identification of knot chirality. Our algorithm adds an extra step in the ordinary calculation of the Alexander polynomial. This extra step only slightly increases the computational cost. The correctness of our algorithm has been proved mathematically by us. The implication of this algorithm in physical research has been demonstrated by our studies of the tube model for polymer knots. Without this algorithm, we would be unable to obtain the tubes for polymer knots.</p></div>","PeriodicalId":517,"journal":{"name":"Chinese Journal of Polymer Science","volume":"42 12","pages":"2030 - 2037"},"PeriodicalIF":4.1,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142778166","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}
Polyimide (PI) is widely used in high-frequency communication technology due to its exceptional comprehensive properties. However, traditional PI has a relatively elevated dielectric constant and dielectric loss. Herein, the different cross-linked structures were introduced in PI matrix and conducted a detailed discussion on the influence of cross-linking agent content and cross-linking structure type on the overall performance of PI films. In comparison to the dielectric constant of 2.9 of neat PI, PI with an interchain cross-linking structure containing 2 wt% 1,3,5-tris(4-aminophenyl)benzene (TAPB) (interchain-PI-2) exhibited the reduced dielectric constant of 2.55 at 1 MHz. The PI films with intrachain cross-linking structure containing 2 wt% TAPB (intrachain-PI-2) exhibited the lowest dielectric constant of 2.35 and the minimum dielectric loss of 0.0075 at 1 MHz. It was due to the more entanglement junctions of intrachain-PI resulting in decreased carrier transport. The thermal expansion coefficients of both interchain-PI and intrachain-PI films were effectively reduced. Moreover, in contrast to interchain-PI films, the intrachain-PI films maintained colorlessness and transparency as the cross-linking agent content increased. This work compared the effects of two different cross-linked structures on the performance of PI films and provided a feasible way to obtain low-k PI films with excellent comprehensive performance for 5G applications.
聚酰亚胺(PI)因其优异的综合性能而被广泛应用于高频通信技术中。然而,传统 PI 的介电常数和介电损耗相对较高。本文在 PI 基体中引入了不同的交联结构,并详细讨论了交联剂含量和交联结构类型对 PI 薄膜综合性能的影响。与纯 PI 2.9 的介电常数相比,含有 2 wt% 1,3,5-三(4-氨基苯基)苯(TAPB)的链间交联结构 PI(链间-PI-2)在 1 MHz 下的介电常数降低到 2.55。含有 2 wt% TAPB 的链内交联结构的 PI 薄膜(链内-PI-2)在 1 MHz 下的介电常数最低,为 2.35,介电损耗最小,为 0.0075。这是由于链内-PI 的纠缠结较多,导致载流子传输减少。链间 PI 和链内 PI 薄膜的热膨胀系数都有效降低。此外,与链间-PI 薄膜相比,链内-PI 薄膜随着交联剂含量的增加而保持无色透明。这项研究比较了两种不同交联结构对 PI 薄膜性能的影响,为获得综合性能优异的低 K 值 PI 薄膜提供了一种可行的方法,可用于 5G 应用。
{"title":"Comparative Study of Intrachain versus Interchain Cross-linking on the Mechanical, Thermal and Dielectric Properties of Low-k Polyimide","authors":"Wan-Jing Zhao, Yi-Zhang Tong, Pei-Pei Zeng, Yang-Sheng Zhou, Xian-Wu Cao, Wei Wu","doi":"10.1007/s10118-024-3186-5","DOIUrl":"10.1007/s10118-024-3186-5","url":null,"abstract":"<div><p>Polyimide (PI) is widely used in high-frequency communication technology due to its exceptional comprehensive properties. However, traditional PI has a relatively elevated dielectric constant and dielectric loss. Herein, the different cross-linked structures were introduced in PI matrix and conducted a detailed discussion on the influence of cross-linking agent content and cross-linking structure type on the overall performance of PI films. In comparison to the dielectric constant of 2.9 of neat PI, PI with an interchain cross-linking structure containing 2 wt% 1,3,5-tris(4-aminophenyl)benzene (TAPB) (interchain-PI-2) exhibited the reduced dielectric constant of 2.55 at 1 MHz. The PI films with intrachain cross-linking structure containing 2 wt% TAPB (intrachain-PI-2) exhibited the lowest dielectric constant of 2.35 and the minimum dielectric loss of 0.0075 at 1 MHz. It was due to the more entanglement junctions of intrachain-PI resulting in decreased carrier transport. The thermal expansion coefficients of both interchain-PI and intrachain-PI films were effectively reduced. Moreover, in contrast to interchain-PI films, the intrachain-PI films maintained colorlessness and transparency as the cross-linking agent content increased. This work compared the effects of two different cross-linked structures on the performance of PI films and provided a feasible way to obtain low-<i>k</i> PI films with excellent comprehensive performance for 5G applications.</p></div>","PeriodicalId":517,"journal":{"name":"Chinese Journal of Polymer Science","volume":"42 11","pages":"1824 - 1834"},"PeriodicalIF":4.1,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142600699","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}
Metal-backboned polymers with anisotropy microstructures are promising for conductive, optoelectronic, and magnetic functional materials. However, the structure-property relationships governing the interplay between the chemical structure and electromagnetic property of the metal-backboned polymer have been rarely investigated. Here we report a carbon/nickel hybrid from metal-backboned polymer to serve as electromagnetic wave-absorbing materials, which exhibit high microwave absorption capacity and tunable absorption band. The presence of nickel backbones promote the generation of heterogeneous interfaces with carbon during calcination, thereby enhancing the wave-absorbing capacity of the carbon/nickel hybrid. The C/Ni hybrids show a minimal reflection loss of −49.1 dB at 13.04 GHz, and its frequency of the absorption band can be adjusted by controlling the thickness of the absorption layer.
{"title":"High Performance Microwave Absorption Material Based on Metal-Backboned Polymer","authors":"Jia-Ning Xu, Kai-Wen Zeng, Yi-Feng Zhang, Yi-Bei Yang, Zi-Wei Liu, Yue Liu, Jia-Jia Wang, Kai-Lin Zhang, Yan-Ru-Zhen Wu, Hao Sun, Hui-Sheng Peng","doi":"10.1007/s10118-024-3181-x","DOIUrl":"10.1007/s10118-024-3181-x","url":null,"abstract":"<div><p>Metal-backboned polymers with anisotropy microstructures are promising for conductive, optoelectronic, and magnetic functional materials. However, the structure-property relationships governing the interplay between the chemical structure and electromagnetic property of the metal-backboned polymer have been rarely investigated. Here we report a carbon/nickel hybrid from metal-backboned polymer to serve as electromagnetic wave-absorbing materials, which exhibit high microwave absorption capacity and tunable absorption band. The presence of nickel backbones promote the generation of heterogeneous interfaces with carbon during calcination, thereby enhancing the wave-absorbing capacity of the carbon/nickel hybrid. The C/Ni hybrids show a minimal reflection loss of −49.1 dB at 13.04 GHz, and its frequency of the absorption band can be adjusted by controlling the thickness of the absorption layer.</p></div>","PeriodicalId":517,"journal":{"name":"Chinese Journal of Polymer Science","volume":"42 12","pages":"1881 - 1887"},"PeriodicalIF":4.1,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142265638","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}
Electrospun nanofibrous separators, despite lacking superior mechanical strength, have gained widespread attention with high porosity and facile processing. Herein, utilizing the fact that thermal imidization temperature of poly(amic acid) (PAA) into polyimide (PI) coincides with the pre-oxidation temperature of polyacrylonitrile (PAN) into carbon fiber, we proposed a new cross-electrospinning strategy to obtain a composite nanofibrous separator (PI/oPAN) randomly interwoven by PI and pre-oxidized PAN (oPAN) nanofibers, via synchronously electrospinning the PAA and PAN onto the same collector and then heat-treating for 2 h at 300 °C. The resultant PI/oPAN separator was able to preserve high porosity (71.7%), electrolyte wettability and thermal stability of PI nanofibrous membrane, and surprisingly exhibited high mechanical strength, being 3 times of PI, which mainly because of the numerous adhesion points generated by the melting of PAN in the pre-oxidation process. Meanwhile, the polar groups of oPAN and 3D fibrous network enhanced the PI/oPAN separator’s ionic conductivity and Li+ transference number, rendering the corresponding cell with more stable cycling performance than cells assembled with pure PI, PAN or commercial PP separator. Therefore, this work might provide a new avenue for the ongoing design and further development of LIB separators capable of high safety and high performance.
电纺纳米纤维分隔物虽然缺乏出色的机械强度,但却以孔隙率高、加工简便而受到广泛关注。在此,我们利用聚酰胺(PAA)转化为聚酰亚胺(PI)的热亚胺化温度与聚丙烯腈(PAN)转化为碳纤维的预氧化温度相吻合这一事实,提出了一种新的交叉电纺策略,通过将 PAA 和 PAN 同步电纺到同一集电体上,然后在 300 °C 下热处理 2 小时,获得由 PI 和预氧化 PAN(oPAN)纳米纤维随机交织而成的复合纳米纤维分离器(PI/oPAN)。由此制得的 PI/oPAN 分离器能够保持 PI 纳米纤维膜的高孔隙率(71.7%)、电解质润湿性和热稳定性,并出人意料地表现出较高的机械强度,是 PI 的 3 倍,这主要是因为 PAN 在预氧化过程中熔化产生了大量的附着点。同时,oPAN 的极性基团和三维纤维网增强了 PI/oPAN 隔膜的离子传导性和 Li+ 传递数,使相应的电池比纯 PI、PAN 或商用 PP 隔膜组装的电池具有更稳定的循环性能。因此,这项工作可能会为正在进行的高安全性和高性能锂离子电池隔膜的设计和进一步开发提供新的途径。
{"title":"Robust Composite Separator Randomly Interwoven by PI and Pre-oxidized PAN Nanofibers for High Performance Lithium-ion Batteries","authors":"Ying Li, Chen Pan, Feng Gan, Zhi-Xun Lin, Jin-Chao Yu, Zhen-Zhen Wei, Yan Zhao","doi":"10.1007/s10118-024-3180-y","DOIUrl":"10.1007/s10118-024-3180-y","url":null,"abstract":"<div><p>Electrospun nanofibrous separators, despite lacking superior mechanical strength, have gained widespread attention with high porosity and facile processing. Herein, utilizing the fact that thermal imidization temperature of poly(amic acid) (PAA) into polyimide (PI) coincides with the pre-oxidation temperature of polyacrylonitrile (PAN) into carbon fiber, we proposed a new cross-electrospinning strategy to obtain a composite nanofibrous separator (PI/oPAN) randomly interwoven by PI and pre-oxidized PAN (oPAN) nanofibers, <i>via</i> synchronously electrospinning the PAA and PAN onto the same collector and then heat-treating for 2 h at 300 °C. The resultant PI/oPAN separator was able to preserve high porosity (71.7%), electrolyte wettability and thermal stability of PI nanofibrous membrane, and surprisingly exhibited high mechanical strength, being 3 times of PI, which mainly because of the numerous adhesion points generated by the melting of PAN in the pre-oxidation process. Meanwhile, the polar groups of oPAN and 3D fibrous network enhanced the PI/oPAN separator’s ionic conductivity and Li<sup>+</sup> transference number, rendering the corresponding cell with more stable cycling performance than cells assembled with pure PI, PAN or commercial PP separator. Therefore, this work might provide a new avenue for the ongoing design and further development of LIB separators capable of high safety and high performance.</p></div>","PeriodicalId":517,"journal":{"name":"Chinese Journal of Polymer Science","volume":"42 11","pages":"1768 - 1779"},"PeriodicalIF":4.1,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142265640","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 : 2024-09-13DOI: 10.1007/s10118-024-3204-7
Qian Zhang, Zi-Yang Xu, Wen-Guang Liu
Hydrogen bonds (H-bonds) are the most essential non-covalent interactions in nature, playing a crucial role in stabilizing the secondary structures of proteins. Taking inspiration from nature, researchers have developed several multiple H-bonds crosslinked supramolecular polymer materials through the incorporation of H-bond side-chain units into the polymer chains. N-acryloyl glycinamide (NAGA) is a monomer with dual amides in the side group, which facilitates the formation of multiple dense intermolecular H-bonds within poly(N-acryloyl glycinamide) (PNAGA), thereby exhibiting diverse properties dependent on concentration and meeting various requirements across different applications. Moreover, numerous attempts have been undertaken to synthesize diverse NAGA-derived units through meticulous chemical structure regulation and fabricate corresponding H-bonding crosslinked supramolecular polymer materials. Despite this, the systematic clarification of the impact of chemical structures of side moieties on intermolecular associations and material performances remains lacking. The present review will focus on the design principle for synthesizing NAGA-derived H-bond side-chain units and provide an overview of the recent advancements in multiple H-bonds crosslinked PNAGA-derived supramolecular polymer materials, which can be categorized into three groups based on the chemical structure of H-bonds units: (1) monomers with solely cooperative H-bonds; (2) monomers with synergistic H-bonds and other physical interactions; and (3) diol chain extenders with cooperative H-bonds. The significance of subtle structural variations in these NAGA-derived units, enabling the fabrication of hydrogen-bonded supramolecular polymer materials with significantly diverse performances, will be emphasized. Moreover, the extensive applications of multiple H-bonds crosslinked supramolecular polymer materials will be elucidated.
氢键(H 键)是自然界中最基本的非共价相互作用,在稳定蛋白质二级结构方面发挥着至关重要的作用。研究人员从大自然中汲取灵感,通过在聚合物链中加入氢键侧链单元,开发出了多种多重氢键交联超分子聚合物材料。N-acryloyl glycinamide(NAGA)是一种侧基中含有双酰胺的单体,它有助于在聚(N-丙烯酰基甘氨酰胺)(PNAGA)中形成多个致密的分子间 H 键,从而根据浓度的不同表现出不同的特性,满足不同应用领域的各种要求。此外,人们还进行了大量尝试,通过细致的化学结构调整合成各种 NAGA 衍生单元,并制造出相应的 H 键交联超分子聚合物材料。尽管如此,关于侧分子化学结构对分子间关联和材料性能影响的系统性阐明仍然缺乏。本综述将重点介绍合成 NAGA 衍生 H 键侧链单元的设计原理,并概述多重 H 键交联 PNAGA 衍生超分子聚合物材料的最新进展。根据 H 键单元的化学结构,这些材料可分为三类:(1) 仅具有协同 H 键的单体;(2) 具有协同 H 键和其他物理相互作用的单体;以及 (3) 具有协同 H 键的二元醇扩链剂。我们将强调这些 NAGA 衍生单元中微妙结构变化的意义,这些微妙结构变化使得氢键超分子聚合物材料的制造具有显著的不同性能。此外,还将阐明多重氢键交联超分子聚合物材料的广泛应用。
{"title":"Hydrogen-Bonding Crosslinked Supramolecular Polymer Materials: From Design Evolution of Side-Chain Hydrogen-Bonding to Applications","authors":"Qian Zhang, Zi-Yang Xu, Wen-Guang Liu","doi":"10.1007/s10118-024-3204-7","DOIUrl":"10.1007/s10118-024-3204-7","url":null,"abstract":"<div><p>Hydrogen bonds (H-bonds) are the most essential non-covalent interactions in nature, playing a crucial role in stabilizing the secondary structures of proteins. Taking inspiration from nature, researchers have developed several multiple H-bonds crosslinked supramolecular polymer materials through the incorporation of H-bond side-chain units into the polymer chains. N-acryloyl glycinamide (NAGA) is a monomer with dual amides in the side group, which facilitates the formation of multiple dense intermolecular H-bonds within poly(<i>N</i>-acryloyl glycinamide) (PNAGA), thereby exhibiting diverse properties dependent on concentration and meeting various requirements across different applications. Moreover, numerous attempts have been undertaken to synthesize diverse NAGA-derived units through meticulous chemical structure regulation and fabricate corresponding H-bonding crosslinked supramolecular polymer materials. Despite this, the systematic clarification of the impact of chemical structures of side moieties on intermolecular associations and material performances remains lacking. The present review will focus on the design principle for synthesizing NAGA-derived H-bond side-chain units and provide an overview of the recent advancements in multiple H-bonds crosslinked PNAGA-derived supramolecular polymer materials, which can be categorized into three groups based on the chemical structure of H-bonds units: (1) monomers with solely cooperative H-bonds; (2) monomers with synergistic H-bonds and other physical interactions; and (3) diol chain extenders with cooperative H-bonds. The significance of subtle structural variations in these NAGA-derived units, enabling the fabrication of hydrogen-bonded supramolecular polymer materials with significantly diverse performances, will be emphasized. Moreover, the extensive applications of multiple H-bonds crosslinked supramolecular polymer materials will be elucidated.</p></div>","PeriodicalId":517,"journal":{"name":"Chinese Journal of Polymer Science","volume":"42 11","pages":"1619 - 1641"},"PeriodicalIF":4.1,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142265639","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 : 2024-09-13DOI: 10.1007/s10118-024-3190-9
E. E. Kim, T. O. Ershova, A. S. Belova, D. A. Khanin, E. V. Bashkova, G. G. Nikiforova, Yu. N. Kononevich, A. A. Anisimov, O. I. Shchegolikhina, A. M. Muzafarov
Nowadays organosilicon luminescent materials are of increasing interest due to the variety of their synthetic or modification techniques and application fields. Ladder polyphenylsilsesquioxanes (L-PPSQ) are a unique class of organosilicon polymers, which can be ideal matrices for the luminescent composites due to their high thermal stability, optical transparency and mechanical strength. In this work, new mechanically strong, heat-resistant, transparent and sensitive to ammonia vapor luminescent composite films based on L-PPSQ have been obtained. As the source of Europium ions oligophenyleuropiumsiloxane was used, demonstrating perfect compatibility to the matrix due to the similar nature. To improve luminescent properties of the films, new organosilicon ligands were introduced into the composites and their influence on the properties of the materials was studied. Valuable properties of described composites may allow their further application as multifunctional coatings.
{"title":"Luminescent Composite Films Based on Mechanically Strong Ladder-like Polyphenylsilsesquioxane and Oligophenyleuropiumsiloxane","authors":"E. E. Kim, T. O. Ershova, A. S. Belova, D. A. Khanin, E. V. Bashkova, G. G. Nikiforova, Yu. N. Kononevich, A. A. Anisimov, O. I. Shchegolikhina, A. M. Muzafarov","doi":"10.1007/s10118-024-3190-9","DOIUrl":"10.1007/s10118-024-3190-9","url":null,"abstract":"<div><p>Nowadays organosilicon luminescent materials are of increasing interest due to the variety of their synthetic or modification techniques and application fields. Ladder polyphenylsilsesquioxanes (L-PPSQ) are a unique class of organosilicon polymers, which can be ideal matrices for the luminescent composites due to their high thermal stability, optical transparency and mechanical strength. In this work, new mechanically strong, heat-resistant, transparent and sensitive to ammonia vapor luminescent composite films based on L-PPSQ have been obtained. As the source of Europium ions oligophenyleuropiumsiloxane was used, demonstrating perfect compatibility to the matrix due to the similar nature. To improve luminescent properties of the films, new organosilicon ligands were introduced into the composites and their influence on the properties of the materials was studied. Valuable properties of described composites may allow their further application as multifunctional coatings.</p></div>","PeriodicalId":517,"journal":{"name":"Chinese Journal of Polymer Science","volume":"42 11","pages":"1793 - 1801"},"PeriodicalIF":4.1,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142265641","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 : 2024-09-02DOI: 10.1007/s10118-024-3187-4
Xiang-Xi Cui, Li Shang, Zhong-Wen Liu, Zhao-Tie Liu, Jin-Qiang Jiang, Guo Li
Developing hydroscopic actuators with simultaneous high elasticity, shape programmability and tunable actuating behaviors are highly desired but still challenging. In this study, we propose an orthogonal composite design to develop such a material. The developed composite elastomer comprises carboxyl group-grafted polystyrene-block-poly(ethylene-co-butylene)-block-polystyrene (SEBS-g-COOH) as the elastic substrate, and a synthesized azobenzene derivative as the functional filler (Azo12). By surface treatment using acidic and base solutions, the carboxyl groups on the surface can reversibly transform into carboxylate groups, which render the composite tunable hygroscopic actuating functionality. On another aspect, the added filler undergoes trans-to-cis isomerization when exposed to UV light irradiation, leading to liquefaction of the crystalline aggregates formed by Azo12 molecules. The liquefied Azo12 molecules can autonomously resotre their trans form and reform the crystalline structure. This reversible change in crystralline structure is utilized to realize the shape memory property, and 5 wt% of Azo12 addition is adequate for the composite to exhibit photo-responsive shape memory behavior without compromising much of the elasricity. The regualtion of external geometry by shape memory effect is effective in altering the actuating behavior. The proposed method can be extend to designing different composites with the demonstrated functionalities.
{"title":"A Composite Elastomer with Photo-responsive Shape Memory and Programmable Hygroscopic Actuation Functionalities","authors":"Xiang-Xi Cui, Li Shang, Zhong-Wen Liu, Zhao-Tie Liu, Jin-Qiang Jiang, Guo Li","doi":"10.1007/s10118-024-3187-4","DOIUrl":"10.1007/s10118-024-3187-4","url":null,"abstract":"<div><p>Developing hydroscopic actuators with simultaneous high elasticity, shape programmability and tunable actuating behaviors are highly desired but still challenging. In this study, we propose an orthogonal composite design to develop such a material. The developed composite elastomer comprises carboxyl group-grafted polystyrene-block-poly(ethylene-<i>co</i>-butylene)-block-polystyrene (SEBS-<i>g</i>-COOH) as the elastic substrate, and a synthesized azobenzene derivative as the functional filler (Azo12). By surface treatment using acidic and base solutions, the carboxyl groups on the surface can reversibly transform into carboxylate groups, which render the composite tunable hygroscopic actuating functionality. On another aspect, the added filler undergoes <i>trans</i>-to-<i>cis</i> isomerization when exposed to UV light irradiation, leading to liquefaction of the crystalline aggregates formed by Azo12 molecules. The liquefied Azo12 molecules can autonomously resotre their trans form and reform the crystalline structure. This reversible change in crystralline structure is utilized to realize the shape memory property, and 5 wt% of Azo12 addition is adequate for the composite to exhibit photo-responsive shape memory behavior without compromising much of the elasricity. The regualtion of external geometry by shape memory effect is effective in altering the actuating behavior. The proposed method can be extend to designing different composites with the demonstrated functionalities.</p></div>","PeriodicalId":517,"journal":{"name":"Chinese Journal of Polymer Science","volume":"42 10","pages":"1470 - 1478"},"PeriodicalIF":4.1,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142188910","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 : 2024-09-02DOI: 10.1007/s10118-024-3184-7
Shi-Long Wu, Huan-Huan Yang, Quan Chen
In this study, we synthesized a series of ABA-type vitrimers by crosslinking the short A moieties of precursors with a bifunctional crosslinker and evaporating the small molecular byproduct. The vitrimer samples thus prepared exhibit linear viscoelasticity dependent on the length of A moiety as well as the content of the crosslinks. When the average number of A monomers per end moiety m=1.1, the crosslinker can only extend the chain but not crosslink the chain. When m becomes 2.8 or higher, introducing a crosslinker first leads to the gelation, whereas excess in crosslinker molecules leads opening of the crosslinking sites and accordingly reentry into the sol regime. Surprisingly, a further increase in the length of the A moieties increases the relaxation time much weaker than the exponential increase seen for the physically crosslinked ABA-type ionomers. We attribute this difference to the distinct relaxation mechanisms: the relaxation of the vitrimer samples is based on relatively independent exchange reactions, which contrasts with the ABA-type ionomers that relax through the collective hopping of connected ionic groups from one ion aggregate to another.
在本研究中,我们通过用双官能团交联剂交联前体的短 A 分子并蒸发小分子副产物,合成了一系列 ABA 型玻璃聚合物。由此制备的玻璃聚合物样品表现出线性粘弹性,这与 A 分子的长度以及交联剂的含量有关。当每个末端分子 A 单体的平均数量 m=1.1 时,交联剂只能延长链,而不能使链交联。当 m 达到 2.8 或更高时,引入交联剂首先会导致凝胶化,而过量的交联剂分子则会导致交联位点打开,从而重新进入溶胶状态。令人惊讶的是,进一步增加 A 分子的长度所增加的弛豫时间比物理交联 ABA 型离子聚合物的指数增长要弱得多。我们将这种差异归因于不同的松弛机制:玻璃聚合物样品的松弛是基于相对独立的交换反应,而 ABA 型离子聚合物则是通过连接离子基团从一个离子聚合体到另一个离子聚合体的集体跳跃来松弛的。
{"title":"Linear Viscoelasticity of ABA-type Vitrimer Based on Dioxaborolane Metathesis","authors":"Shi-Long Wu, Huan-Huan Yang, Quan Chen","doi":"10.1007/s10118-024-3184-7","DOIUrl":"10.1007/s10118-024-3184-7","url":null,"abstract":"<div><p>In this study, we synthesized a series of ABA-type vitrimers by crosslinking the short A moieties of precursors with a bifunctional crosslinker and evaporating the small molecular byproduct. The vitrimer samples thus prepared exhibit linear viscoelasticity dependent on the length of A moiety as well as the content of the crosslinks. When the average number of A monomers per end moiety <i>m</i>=1.1, the crosslinker can only extend the chain but not crosslink the chain. When <i>m</i> becomes 2.8 or higher, introducing a crosslinker first leads to the gelation, whereas excess in crosslinker molecules leads opening of the crosslinking sites and accordingly reentry into the sol regime. Surprisingly, a further increase in the length of the A moieties increases the relaxation time much weaker than the exponential increase seen for the physically crosslinked ABA-type ionomers. We attribute this difference to the distinct relaxation mechanisms: the relaxation of the vitrimer samples is based on relatively independent exchange reactions, which contrasts with the ABA-type ionomers that relax through the collective hopping of connected ionic groups from one ion aggregate to another.</p></div>","PeriodicalId":517,"journal":{"name":"Chinese Journal of Polymer Science","volume":"42 10","pages":"1495 - 1504"},"PeriodicalIF":4.1,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142188902","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 : 2024-09-02DOI: 10.1007/s10118-024-3199-0
Zhen-Yu Wang, Xiao-Kong Liu
Polyimides are a family of high-tech plastics that have irreplaceable applications in the fields of aerospace, defense, and opto-electronics, but polyimides are difficult to be reprocessed and recycled at the end of their service life, resulting in a significant waste of resources. Hence, it is of great significance to develop recyclable polyimides with comparable properties to the commercial products. Herein, we report a novel polymer-to-monomers chemically recyclable poly(imide-imine) (PtM-CR-PII) plastic, synthesized by cross-linking the amine-terminated aromatic bisimide monomer and the hexa-vanillin terminated cyclophosphazene monomer via dynamic imine bonds. The PtM-CR-PII plastic exhibits comparable mechanical and thermal properties as well as chemical stability to the commercial polyimides. The PtM-CR-PII plastic possesses a high Young’s modulus of ≈3.2 GPa and a tensile strength as high as ≈108 MPa, which also exhibits high thermal stability with a glass transition temperature of ≈220 °C. Moreover, the PtM-CR-PII plastic exhibits outstanding waterproofness, acid/alkali-resistance, and solvent-resistance, its appearance and mechanical properties can be well maintained after long-term soaking in water, highly concentrated acid and base, and various organic solvents. Furthermore, the cyclophosphazene moieties endow the PtM-CR-PII plastic with excellent flame retardancy. The PtM-CR-PII plastic exhibits the highest UL-94 flame-retarding rating of V-0 and a limiting oxygen index (LOI) value of 45.5%. Importantly, the PtM-CR-PII plastic can be depolymerized in an organic solvents-acid mixture medium at room temperature, allowing easy separation and recovery of both monomers in high purity. The recovered pure monomers can be used to regenerate new PtM-CR-PII plastics, enabling sustainable polymer-monomers-polymer circulation.
{"title":"Polymer-to-Monomers Chemically Recyclable Poly(imide-imine) Plastics with Extreme-Condition Resistance and Flame Retardancy","authors":"Zhen-Yu Wang, Xiao-Kong Liu","doi":"10.1007/s10118-024-3199-0","DOIUrl":"10.1007/s10118-024-3199-0","url":null,"abstract":"<div><p>Polyimides are a family of high-tech plastics that have irreplaceable applications in the fields of aerospace, defense, and opto-electronics, but polyimides are difficult to be reprocessed and recycled at the end of their service life, resulting in a significant waste of resources. Hence, it is of great significance to develop recyclable polyimides with comparable properties to the commercial products. Herein, we report a novel polymer-to-monomers chemically recyclable poly(imide-imine) (PtM-CR-PII) plastic, synthesized by cross-linking the amine-terminated aromatic bisimide monomer and the hexa-vanillin terminated cyclophosphazene monomer via dynamic imine bonds. The PtM-CR-PII plastic exhibits comparable mechanical and thermal properties as well as chemical stability to the commercial polyimides. The PtM-CR-PII plastic possesses a high Young’s modulus of ≈3.2 GPa and a tensile strength as high as ≈108 MPa, which also exhibits high thermal stability with a glass transition temperature of ≈220 °C. Moreover, the PtM-CR-PII plastic exhibits outstanding waterproofness, acid/alkali-resistance, and solvent-resistance, its appearance and mechanical properties can be well maintained after long-term soaking in water, highly concentrated acid and base, and various organic solvents. Furthermore, the cyclophosphazene moieties endow the PtM-CR-PII plastic with excellent flame retardancy. The PtM-CR-PII plastic exhibits the highest UL-94 flame-retarding rating of V-0 and a limiting oxygen index (LOI) value of 45.5%. Importantly, the PtM-CR-PII plastic can be depolymerized in an organic solvents-acid mixture medium at room temperature, allowing easy separation and recovery of both monomers in high purity. The recovered pure monomers can be used to regenerate new PtM-CR-PII plastics, enabling sustainable polymer-monomers-polymer circulation.</p></div>","PeriodicalId":517,"journal":{"name":"Chinese Journal of Polymer Science","volume":"42 10","pages":"1525 - 1535"},"PeriodicalIF":4.1,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142188904","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}