An annealing study of oriented amorphous fibers was conducted to uncover the molecular origin of polylactide (PLA) mesophase and its thermal stability. A quiescent and isothermal annealing treatment was carried out at temperature < Tg to avoid crystallization but suffice to activate the concerned structure. WAXS and FTIR analyses were used to detect the structure and related molecular interactions. DSC analysis was used to examine the thermal response and stability. The results showed that the mesophase was developed readily in the annealed fibers, along with enhanced dipole-dipole interactions between the C=O groups. These were realized through the conformational rearrangement during which the distance between the C=O groups was shortened sufficiently. It is the stress-induced orientation in the annealed fibers that reduces the kinetic barrier and promotes the energetically more favorable conformational rearrangement. Upon heated above Tg, the mesophase formed in the annealed fibers was not destructed but grew up during the subsequent heat-treatment.
{"title":"Studies on Molecular Origin of Polylactide Mesophase and its Thermal Stability","authors":"Wenhao Ge, Wei Huang, Xiang Zhang, Lai Wei, Peng Wang, Peng Chen","doi":"10.1016/j.polymer.2025.128025","DOIUrl":"https://doi.org/10.1016/j.polymer.2025.128025","url":null,"abstract":"An annealing study of oriented amorphous fibers was conducted to uncover the molecular origin of polylactide (PLA) mesophase and its thermal stability. A quiescent and isothermal annealing treatment was carried out at temperature < <em>T</em><sub>g</sub> to avoid crystallization but suffice to activate the concerned structure. WAXS and FTIR analyses were used to detect the structure and related molecular interactions. DSC analysis was used to examine the thermal response and stability. The results showed that the mesophase was developed readily in the annealed fibers, along with enhanced dipole-dipole interactions between the C=O groups. These were realized through the conformational rearrangement during which the distance between the C=O groups was shortened sufficiently. It is the stress-induced orientation in the annealed fibers that reduces the kinetic barrier and promotes the energetically more favorable conformational rearrangement. Upon heated above <em>T</em><sub>g</sub>, the mesophase formed in the annealed fibers was not destructed but grew up during the subsequent heat-treatment.","PeriodicalId":405,"journal":{"name":"Polymer","volume":"97 1","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142924904","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}
Developing polyurethane that can withstand ultra-low temperatures is key to expanding its applications in low-temperature environments. Spider silk demonstrates high toughness in low-temperature environments due to its hierarchical hydrogen bonds network. Inspired by spider silk, a polyurethane elastomer (SPU-DTPx) with exceptional strength, superior toughness, low-temperature resistance, and recyclability were synthesized. The dense hydrogen bonds in the urethane bonds lead to curled and entangled molecular chains at low temperature. SPU-DTP0.8 achieves a maximum tensile strength of 86.71 MPa, maximum elongation at break reaching 226.93% at -90 °C, with toughness of SPU-DTP0.8 of 109.98 MJ m-3, only 37.27% lower than that at 20 °C. Utilizing hydrogen bonds and molecular chain migration, SPU-DTP0.8 demonstrates excellent recyclability, maintaining key mechanical properties after reprocessing. This elastomer could endure extreme supercold temperatures and offer considerable promise for creating elastic devices, flexible spacecraft, and soft robots designed for use in extremely low-temperature environments like outer space or polar areas.
开发可耐受超低温的聚氨酯是扩大其在低温环境中应用的关键。蜘蛛丝因其分层氢键网络而在低温环境中表现出很高的韧性。受蜘蛛丝的启发，我们合成了一种聚氨酯弹性体（SPU-DTPx），它具有超高强度、超强韧性、耐低温性和可回收性。聚氨酯键中密集的氢键导致分子链在低温下卷曲缠绕。SPU-DTP0.8 的最大拉伸强度为 86.71 兆帕，在 -90 °C 时的最大断裂伸长率为 226.93%，SPU-DTP0.8 的韧性为 109.98 兆焦耳/立方米，仅比 20 °C 时的韧性低 37.27%。利用氢键和分子链迁移，SPU-DTP0.8 表现出卓越的可回收性，在再加工后仍能保持关键的机械性能。这种弹性体可以承受极端的超低温，为制造弹性设备、柔性航天器和软机器人提供了巨大的前景，这些设备专为在外太空或极地等极低温环境中使用而设计。
{"title":"Spider silk-inspired tough and recyclable polyurethane with supercold tolerance","authors":"Bowen Tan, Liming Tao, Shoubing Chen, Zenghui Yang, Qihua Wang, Lihe Guo, Zhangzhang Tang, Rui Yang, Qian Dou, Xinrui Zhang, Yuqi Li, Tingmei Wang","doi":"10.1016/j.polymer.2025.128021","DOIUrl":"https://doi.org/10.1016/j.polymer.2025.128021","url":null,"abstract":"Developing polyurethane that can withstand ultra-low temperatures is key to expanding its applications in low-temperature environments. Spider silk demonstrates high toughness in low-temperature environments due to its hierarchical hydrogen bonds network. Inspired by spider silk, a polyurethane elastomer (SPU-DTP<sub>x</sub>) with exceptional strength, superior toughness, low-temperature resistance, and recyclability were synthesized. The dense hydrogen bonds in the urethane bonds lead to curled and entangled molecular chains at low temperature. SPU-DTP<sub>0.8</sub> achieves a maximum tensile strength of 86.71 MPa, maximum elongation at break reaching 226.93% at -90 °C, with toughness of SPU-DTP<sub>0.8</sub> of 109.98 MJ m<sup>-3</sup>, only 37.27% lower than that at 20 °C. Utilizing hydrogen bonds and molecular chain migration, SPU-DTP<sub>0.8</sub> demonstrates excellent recyclability, maintaining key mechanical properties after reprocessing. This elastomer could endure extreme supercold temperatures and offer considerable promise for creating elastic devices, flexible spacecraft, and soft robots designed for use in extremely low-temperature environments like outer space or polar areas.","PeriodicalId":405,"journal":{"name":"Polymer","volume":"132 1","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142917529","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 : 2025-01-02DOI: 10.1016/j.polymer.2025.128019
Lin Zhong, Min Xia, Qing Zhao, Minghao Zhang, Xudong Hou, Yeping Ren, Na He, Ruibin Liu, Yunjun Luo
The development of photocuring 3D printed solid propellants is limited by photosensitive binders. Numerous commercial photosensitive oligomers used as binders for solid propellants fail to meet the performance criteria related to processability, mechanical properties, and safety. Modifying established binders that have been used in solid propellants offers a more cost-effective and dependable approach to prepare photosensitive binders. By utilizing the addition reaction between the isocyanate group in 2-isocyanatoethyl acrylate (AOI) and the hydroxyl group in hydroxyl-terminated polyether (HTPE), we successfully modified HTPE to synthesize acrylate-terminated polyether (ATPE), which exhibits the capability of undergoing free radical polymerization. The molecular weight distribution of HTPE and ATPE, as well as the correlated characteristic absorption peaks, were analyzed using gel permeation chromatography (GPC) and Fourier transform infrared spectroscopy (FTIR) techniques, respectively. The excellent initiation properties of photoinitiator 819, serving as a photosensitive additive of ATPE, were elucidated by comparing the differences in molar absorption coefficients, initiator decomposition rates, and initiator decomposition rate constants among photoinitiators 184, 819, TPO and TPO-L under UV light at 405 nm. The thermal effects resulting from the photopolymerization of ATPE were investigated using photo differential scanning calorimetry (Photo-DSC), and the characteristics of the photopolymerization reaction, along with polymerization kinetic parameters such as the polymerization rate, growth polymerization rate constant (kp), and termination polymerization rate constant (kt), were analyzed in detail. The synthesis and photopolymerization kinetics of ATPE presented in this work provide valuable support for the photopolymerization 3D printing of solid propellants.
{"title":"Synthesis and Photopolymerization Kinetics of Acrylate-Terminated Polyether for Additive Manufacturing","authors":"Lin Zhong, Min Xia, Qing Zhao, Minghao Zhang, Xudong Hou, Yeping Ren, Na He, Ruibin Liu, Yunjun Luo","doi":"10.1016/j.polymer.2025.128019","DOIUrl":"https://doi.org/10.1016/j.polymer.2025.128019","url":null,"abstract":"The development of photocuring 3D printed solid propellants is limited by photosensitive binders. Numerous commercial photosensitive oligomers used as binders for solid propellants fail to meet the performance criteria related to processability, mechanical properties, and safety. Modifying established binders that have been used in solid propellants offers a more cost-effective and dependable approach to prepare photosensitive binders. By utilizing the addition reaction between the isocyanate group in 2-isocyanatoethyl acrylate (AOI) and the hydroxyl group in hydroxyl-terminated polyether (HTPE), we successfully modified HTPE to synthesize acrylate-terminated polyether (ATPE), which exhibits the capability of undergoing free radical polymerization. The molecular weight distribution of HTPE and ATPE, as well as the correlated characteristic absorption peaks, were analyzed using gel permeation chromatography (GPC) and Fourier transform infrared spectroscopy (FTIR) techniques, respectively. The excellent initiation properties of photoinitiator 819, serving as a photosensitive additive of ATPE, were elucidated by comparing the differences in molar absorption coefficients, initiator decomposition rates, and initiator decomposition rate constants among photoinitiators 184, 819, TPO and TPO-L under UV light at 405 nm. The thermal effects resulting from the photopolymerization of ATPE were investigated using photo differential scanning calorimetry (Photo-DSC), and the characteristics of the photopolymerization reaction, along with polymerization kinetic parameters such as the polymerization rate, growth polymerization rate constant (k<sub>p</sub>), and termination polymerization rate constant (k<sub>t</sub>), were analyzed in detail. The synthesis and photopolymerization kinetics of ATPE presented in this work provide valuable support for the photopolymerization 3D printing of solid propellants.","PeriodicalId":405,"journal":{"name":"Polymer","volume":"154 1","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142917531","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 : 2025-01-02DOI: 10.1016/j.polymer.2025.128016
Asma Iqbal, Bibi Amna, Ibrahim ul Islam, Zhang Yuchi, Humaira Masood Siddiqi, Jiantao Zai, Xuefeng Qian
Laser-induced graphene (LIG) derived from the polymers has captured a great deal of attention owing to its high efficiency, low-cost fabrication and prospect applications in the flexible energy storage devices. Polyimides have been explored as one of the most popular LIG substrates for the last couple of years. In this work, a novel LIG material has been reported which is prepared from a novel copolyimide. A series of new thermally stable polyimides has been synthesized via copolymerization of diamine containing benzimidazole derivative, namely N1-(4-aminophenyl)-N1-(4-(2-phenyl-1H-benzo[d]imidazole-1-yl)phenyl)benzene-1,4-diamine with four different aromatic anhydrides. Graphene formation and morphology have been examined and confirmed by employing several techniques including Field Emission Scanning Electron Microscopy, Energy Dispersive X-ray and Raman spectroscopy. LIG obtained using these newly reported polyimides was reproducible as well as stable with negligible to no difference in properties and appearance over a long period of time. At 1 mA cm-2, the 11a-LIG electrode displays capacitance of 136 mF cm-2 in KOH electrolyte. Consequently, the symmetric supercapacitor device with LIG electrodes, achieves capacitance of 216 mF cm-2 at 2.5 mA cm-2 using PVA-KOH electrolyte. Newly fabricated supercapacitor device exhibits good cycling stability and excellent mechanical flexibility hence, making it a potential candidate for wearable electronics.
聚合物制备的激光诱导石墨烯（LIG）因其制备效率高、成本低、在柔性储能器件中的应用前景广阔而备受关注。聚酰亚胺是近年来最受欢迎的LIG衬底之一。在这项工作中，报道了一种新的LIG材料，它是由一种新型的共聚物制备的。以含苯并咪唑的二胺衍生物N1-（4-氨基苯基）-N1-（4-（2-苯基- 1h -苯并[d]咪唑-1-基）苯基）苯-1,4-二胺与4种不同的芳香酸酐共聚合成了一系列新的热稳定聚酰亚胺。石墨烯的形成和形态已经通过使用几种技术，包括场发射扫描电子显微镜，能量色散x射线和拉曼光谱来检查和证实。使用这些新报道的聚酰亚胺获得的LIG具有可重复性和稳定性，在很长一段时间内，性能和外观的差异可以忽略不计。在1ma cm-2时，11a-LIG电极在KOH电解质中显示136 mF cm-2的电容。因此，使用PVA-KOH电解液，采用LIG电极的对称超级电容器器件在2.5 mA cm-2下实现了216 mF cm-2的电容。新制备的超级电容器器件具有良好的循环稳定性和优异的机械柔韧性，因此成为可穿戴电子产品的潜在候选者。
{"title":"Thermally stable benzimidazole based co-polyimides and derived LIG for flexible supercapacitors","authors":"Asma Iqbal, Bibi Amna, Ibrahim ul Islam, Zhang Yuchi, Humaira Masood Siddiqi, Jiantao Zai, Xuefeng Qian","doi":"10.1016/j.polymer.2025.128016","DOIUrl":"https://doi.org/10.1016/j.polymer.2025.128016","url":null,"abstract":"Laser-induced graphene (LIG) derived from the polymers has captured a great deal of attention owing to its high efficiency, low-cost fabrication and prospect applications in the flexible energy storage devices. Polyimides have been explored as one of the most popular LIG substrates for the last couple of years. In this work, a novel LIG material has been reported which is prepared from a novel copolyimide. A series of new thermally stable polyimides has been synthesized <em>via</em> copolymerization of diamine containing benzimidazole derivative, namely <em>N</em><sup>1</sup>-(4-aminophenyl)-<em>N</em><sup>1</sup>-(4-(2-phenyl-1<em>H</em>-benzo[<em>d</em>]imidazole-1-yl)phenyl)benzene-1,4-diamine with four different aromatic anhydrides. Graphene formation and morphology have been examined and confirmed by employing several techniques including Field Emission Scanning Electron Microscopy, Energy Dispersive X-ray and Raman spectroscopy. LIG obtained using these newly reported polyimides was reproducible as well as stable with negligible to no difference in properties and appearance over a long period of time. At 1 mA cm<sup>-2</sup>, the <strong>11a-LIG</strong> electrode displays capacitance of 136 mF cm<sup>-2</sup> in KOH electrolyte. Consequently, the symmetric supercapacitor device with LIG electrodes, achieves capacitance of 216 mF cm<sup>-2</sup> at 2.5 mA cm<sup>-2</sup> using PVA-KOH electrolyte. Newly fabricated supercapacitor device exhibits good cycling stability and excellent mechanical flexibility hence, making it a potential candidate for wearable electronics.","PeriodicalId":405,"journal":{"name":"Polymer","volume":"11 1","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142917533","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}
Molecular structure design based on molecular simulation is proving to be an effective method for enhancing the mechanical properties of polymers. However, the conventional fully-crystalline and isotropic models fall short in accurate structural design and performance prediction of high-performance amorphous/semi-crystalline oriented fibers. Herein, uniaxially oriented amorphous/semi-crystalline models established through the NPT ensemble with applied stresses were presented, demonstrating closer agreement with the density and tensile strength of actual high-performance polymer fibers compared to conventional models. Taking aramid fibers for instance, six heterocyclic units were introduced to design heterocyclic aramids with varying strengths of π-π interactions and hydrogen bonding, and the novel models were employed to deeply explore the quantitative relationship between molecular interaction and orientation, as well as their quantitative effects on mechanical properties. It revealed that π-π interactions impose greater restrictions on orientation during the hot-drawing simulation process than hydrogen bonding, and both interactions and orientation play equally important roles in determining tensile strength. Ultimately, the optimal structure was identified as 2-(2-hydroxy-4-aminophenyl)-5(6)-aminobenzimidazole, which exhibited strong hydrogen bonds, high orientation, and excellent tensile strength. This research provides an efficient and feasible simulation method for designing of high-performance amorphous/semi-crystalline oriented fibers.
{"title":"A Modeling and Simulation Method for High-Performance Amorphous/Semi-Crystalline Oriented Fibers: Structural Design and Performance Prediction","authors":"Zheng Li, Wen Zhai, Xu Zhong, Xin Li, Longbo Luo, Xiangyang Liu","doi":"10.1016/j.polymer.2025.128015","DOIUrl":"https://doi.org/10.1016/j.polymer.2025.128015","url":null,"abstract":"Molecular structure design based on molecular simulation is proving to be an effective method for enhancing the mechanical properties of polymers. However, the conventional fully-crystalline and isotropic models fall short in accurate structural design and performance prediction of high-performance amorphous/semi-crystalline oriented fibers. Herein, uniaxially oriented amorphous/semi-crystalline models established through the NPT ensemble with applied stresses were presented, demonstrating closer agreement with the density and tensile strength of actual high-performance polymer fibers compared to conventional models. Taking aramid fibers for instance, six heterocyclic units were introduced to design heterocyclic aramids with varying strengths of π-π interactions and hydrogen bonding, and the novel models were employed to deeply explore the quantitative relationship between molecular interaction and orientation, as well as their quantitative effects on mechanical properties. It revealed that π-π interactions impose greater restrictions on orientation during the hot-drawing simulation process than hydrogen bonding, and both interactions and orientation play equally important roles in determining tensile strength. Ultimately, the optimal structure was identified as 2-(2-hydroxy-4-aminophenyl)-5(6)-aminobenzimidazole, which exhibited strong hydrogen bonds, high orientation, and excellent tensile strength. This research provides an efficient and feasible simulation method for designing of high-performance amorphous/semi-crystalline oriented fibers.","PeriodicalId":405,"journal":{"name":"Polymer","volume":"23 1","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142911493","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 : 2024-12-31DOI: 10.1016/j.polymer.2024.128010
Wan-Gyu Hahm, Hiroshi Ito, Takeshi Kikutani
The structural evolution of poly(ethylene terephthalate) (PET) fibers under high strain rate drawing was investigated using high-speed in-line drawing process comprising three sequential zones: spinning (S), hot-drawing (D), and annealing (DA). PET fibers were drawn at take-up velocities of 5 and 6 km/min with draw ratios ranging from 1 to 2.5. Structural characterization was conducted using two-dimensional wide-angle X-ray diffraction (2D WAXD), birefringence, and density measurements to analyze the evolution of the amorphous phase, oriented mesophase, and crystalline phases throughout the process. Fibers drawn in the D zone exhibited a highly oriented mesophase with a weak but sharp meridional (001') peak in their 2D WAXD patterns. Structural evolution into the crystalline phase occurred independently in the DA zone, where the oriented mesophase acted as a precursor to crystallization. The mechanical properties of the fibers were predominantly influenced by the fraction and orientation of the mesophase developed in the D zone.
{"title":"Structural Evolution of Poly(ethylene terephthalate) Fibers in High-speed In-line Drawing Process","authors":"Wan-Gyu Hahm, Hiroshi Ito, Takeshi Kikutani","doi":"10.1016/j.polymer.2024.128010","DOIUrl":"https://doi.org/10.1016/j.polymer.2024.128010","url":null,"abstract":"The structural evolution of poly(ethylene terephthalate) (PET) fibers under high strain rate drawing was investigated using high-speed in-line drawing process comprising three sequential zones: spinning (S), hot-drawing (D), and annealing (DA). PET fibers were drawn at take-up velocities of 5 and 6 km/min with draw ratios ranging from 1 to 2.5. Structural characterization was conducted using two-dimensional wide-angle X-ray diffraction (2D WAXD), birefringence, and density measurements to analyze the evolution of the amorphous phase, oriented mesophase, and crystalline phases throughout the process. Fibers drawn in the D zone exhibited a highly oriented mesophase with a weak but sharp meridional (001') peak in their 2D WAXD patterns. Structural evolution into the crystalline phase occurred independently in the DA zone, where the oriented mesophase acted as a precursor to crystallization. The mechanical properties of the fibers were predominantly influenced by the fraction and orientation of the mesophase developed in the D zone.","PeriodicalId":405,"journal":{"name":"Polymer","volume":"182 1","pages":""},"PeriodicalIF":4.6,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142905424","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 : 2024-12-31DOI: 10.1016/j.polymer.2024.127990
Ruth N. Schmarsow, Ailín Mateos, Marcelo Ceolín, Ileana A. Zucchi, Walter F. Schroeder
Significant progress has been recently achieved in the in-situ preparation of high-aspect-ratio crystalline micelles in polymer matrices. However, very little is known about how these structures affect the diffusion of permeant molecules through the matrix. This is a key factor for the potential use of these materials as barrier membranes in applications such as containers, coatings or packaging. In this work, we prepare ribbon-like core-crystalline micelles in thermosetting matrices and analyze their impact on the barrier properties. The materials were prepared by crystallization-driven self-assembly (CDSA) of poly(ethylene-block-ethylene oxide) (PE-b-PEO) in two different matrices: diglycidyl ether of bisphenol A (DGEBA) and poly(ethylene glycol) dimethacrylate (PEGDMA). DGEBA is a rigid matrix that can be plasticized by the corona-forming PEO block, whereas PEGDMA is a flexible matrix with a glass transition temperature that matches that of PEO. This approach allowed us to analyze the behavior of the micellar structure by distinguishing between the effects of the rigid crystalline core and the flexible corona. From water diffusion and permeability measurements we demonstrated that barrier properties are markedly improved by the crystalline cores, which act as impermeable obstacles generating a tortuous path for the diffusion of permeant molecules through the polymer matrix. Although the corona-forming block can act as a plasticizer of the matrix, the tortuosity introduced by the crystalline core is the rate-controlling factor and, as such, determines the improvement in barrier properties.
{"title":"Preparation of ribbon-like core-crystalline micelles in epoxy and dimethacrylate matrices for potential applications as barrier membranes","authors":"Ruth N. Schmarsow, Ailín Mateos, Marcelo Ceolín, Ileana A. Zucchi, Walter F. Schroeder","doi":"10.1016/j.polymer.2024.127990","DOIUrl":"https://doi.org/10.1016/j.polymer.2024.127990","url":null,"abstract":"Significant progress has been recently achieved in the in-situ preparation of high-aspect-ratio crystalline micelles in polymer matrices. However, very little is known about how these structures affect the diffusion of permeant molecules through the matrix. This is a key factor for the potential use of these materials as barrier membranes in applications such as containers, coatings or packaging. In this work, we prepare ribbon-like core-crystalline micelles in thermosetting matrices and analyze their impact on the barrier properties. The materials were prepared by crystallization-driven self-assembly (CDSA) of poly(ethylene-<em>block</em>-ethylene oxide) (PE-<em>b</em>-PEO) in two different matrices: diglycidyl ether of bisphenol A (DGEBA) and poly(ethylene glycol) dimethacrylate (PEGDMA). DGEBA is a rigid matrix that can be plasticized by the corona-forming PEO block, whereas PEGDMA is a flexible matrix with a glass transition temperature that matches that of PEO. This approach allowed us to analyze the behavior of the micellar structure by distinguishing between the effects of the rigid crystalline core and the flexible corona. From water diffusion and permeability measurements we demonstrated that barrier properties are markedly improved by the crystalline cores, which act as impermeable obstacles generating a tortuous path for the diffusion of permeant molecules through the polymer matrix. Although the corona-forming block can act as a plasticizer of the matrix, the tortuosity introduced by the crystalline core is the rate-controlling factor and, as such, determines the improvement in barrier properties.","PeriodicalId":405,"journal":{"name":"Polymer","volume":"93 1","pages":""},"PeriodicalIF":4.6,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142908650","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 : 2024-12-31DOI: 10.1016/j.polymer.2024.128001
Chenxu Jiang, Changqing Miao, Jia Zhou, Ming Yuan
Semi-crystalline polymers possess a unique molecular chain arrangement, exhibiting partial order and disorder in the solid state. This distinctive arrangement imparts properties combining both the properties of crystalline and amorphous materials, making semi-crystalline polymers promising candidates for various harsh engineering applications. Considering the complex nature of the microstructure, various service conditions induce different deformation mechanisms and fracture behaviors ranging from the micro level to the macro level. Diverse fracture patterns in spherulites at the macro level have been found, while, at the mesoscopic level, the microstructure and distinct deformation mechanisms of the two phases have not yet been systematically summarized and understood. This paper reviews the relationship between spherulitic microstructure and damage mechanisms of semi-crystalline polymers at the mesoscopic level from both aspects of experimental characterization and numerical modelling. A deeper understanding of the damage behavior is educated based on the state-of-the-art review, which is crucial for providing theoretical support for their broader engineering applications.
{"title":"Insights into Damage Mechanisms and Advances in Numerical Simulation of Spherulitic Polymers","authors":"Chenxu Jiang, Changqing Miao, Jia Zhou, Ming Yuan","doi":"10.1016/j.polymer.2024.128001","DOIUrl":"https://doi.org/10.1016/j.polymer.2024.128001","url":null,"abstract":"Semi-crystalline polymers possess a unique molecular chain arrangement, exhibiting partial order and disorder in the solid state. This distinctive arrangement imparts properties combining both the properties of crystalline and amorphous materials, making semi-crystalline polymers promising candidates for various harsh engineering applications. Considering the complex nature of the microstructure, various service conditions induce different deformation mechanisms and fracture behaviors ranging from the micro level to the macro level. Diverse fracture patterns in spherulites at the macro level have been found, while, at the mesoscopic level, the microstructure and distinct deformation mechanisms of the two phases have not yet been systematically summarized and understood. This paper reviews the relationship between spherulitic microstructure and damage mechanisms of semi-crystalline polymers at the mesoscopic level from both aspects of experimental characterization and numerical modelling. A deeper understanding of the damage behavior is educated based on the state-of-the-art review, which is crucial for providing theoretical support for their broader engineering applications.","PeriodicalId":405,"journal":{"name":"Polymer","volume":"66 1","pages":""},"PeriodicalIF":4.6,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142908654","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 : 2024-12-31DOI: 10.1016/j.polymer.2024.128014
Paola Andrea Benitez-Duif, Sebastian Weckes, Ricardo Ferreira, Daniel Kurka, Joerg C. Tiller
Double network hydrogels (DNHs) are strong and tough materials that surpass the performance of conventional hydrogels, making them highly attractive for various applications in biomedicine, membrane technology, and energy storage. The number of suitable systems known so far is rather limited. We, have recently introduced a poly(2-oxazoline) (POx)-based DNH combined with poly (acrylic acid) that has a superior compressive strength compared to common DNHs entirely composed of two poly(acrylate) networks. To further explore the potential of cross-linked POx as primary networks for DNHs, a series of different poly (acrylate)s was employed as secondary network and the resulting DNHs were investigated regarding their mechanical properties.
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