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Chen H, Liu W, Hong M, Zhang E, Dai X, Qiu X, Ji X. Viscoelastic behavior of high molecular weight polyimide/cyclohexanone solution during sol-gel transition. POLYMER 2020. [DOI: 10.1016/j.polymer.2020.122250] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Zhang M, Niu H, Wu D. Polyimide Fibers with High Strength and High Modulus: Preparation, Structures, Properties, and Applications. Macromol Rapid Commun 2018; 39:e1800141. [DOI: 10.1002/marc.201800141] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 04/18/2018] [Indexed: 11/09/2022]
Affiliation(s)
- Mengying Zhang
- State Key Laboratory of Chemical Resource Engineering; Beijing University of Chemical Technology; Beijing 100029 China
| | - Hongqing Niu
- State Key Laboratory of Chemical Resource Engineering; Beijing University of Chemical Technology; Beijing 100029 China
| | - Dezhen Wu
- State Key Laboratory of Chemical Resource Engineering; Beijing University of Chemical Technology; Beijing 100029 China
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Zhang E, Dai X, Zhu Y, Chen Q, Sun Z, Qiu X, Ji X. Associating behavior of one polyimide with high molecular weight in solution through a relatively weak interaction. POLYMER 2018. [DOI: 10.1016/j.polymer.2018.03.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Zhang E, Zhao Y, Yang W, Chen H, Liu W, Dai X, Qiu X, Ji X. Viscoelastic behaviour and relaxation modes of one polyamic acid organogel studied by rheometers and dynamic light scattering. SOFT MATTER 2017; 14:73-82. [PMID: 29231227 DOI: 10.1039/c7sm02185b] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A novel polyamic acid (PAA from BAPMPO-BPDA) organogel was synthesized and characterized via dynamic light scattering (DLS), a classical rheometer, and diffusion wave spectroscopy (DWS). In situ monitoring was performed using a classical rheometer to observe the formation of the PAA organogel. The rheological curves confirm the formation of the PAA gel network and the origin of hydrogen bonding from the -NH- group (donor) and P[double bond, length as m-dash]O group (acceptor). The autocorrelation functions of PAA under different conditions (pure gel, gel with NaNO3, gel with formamide) are measured via DLS, and different characteristic times are obtained via the CONTIN method. Three different relaxation modes of the PAA gel, i.e., fast, intermediate and slow modes, are observed. The fast and intermediate modes show a diffusive behaviour (τ ∼ q-2), whereas the slow mode did not. When enough formamide is added into the PAA gel, the fast mode disappears; addition of enough salt (NaNO3) leads to disappearance of the slow mode. The relationship between characteristic time and diffusion vector demonstrates that the different decorrelation modes consisted of two homodyne and two heterodyne components. Two single-exponential functions and two stretched exponential functions were used, and the different decorrelation modes of the PAA gel are expressed with a non-linear function, which fits the autocorrelation function very well. And the different decorrelation modes are also discussed. DWS results in the high-frequency region not only demonstrate the formation of a PAA gel network but also indicate that the semiflexible chains of PAA are due to electrostatic interaction. The DWS results at different time scales are analyzed by applying the de Gennes' reptation model.
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Affiliation(s)
- Ensong Zhang
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China.
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Tan W, Dong J, Li Z, Zhang D, Zhao X, Zhang Q. Synthesis of organosoluble copolyimide and preparation of fibers by dry-spinning process on a large scale. HIGH PERFORM POLYM 2017. [DOI: 10.1177/0954008317744868] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
An organosoluble copolyimide (co-PI) was synthesized from 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA), 1,4-bis-(4-aimino-2-triflupromethyl-phenoxy)-benzene ( p-6FAPB), and 2-(4-aminophenyl)-5-aminobenzimidazole (BIA) via the one-step polymerization using N-methyl-2-pyrrolidone (NMP) as the solvent, and high-performance co-PI fibers were directly prepared by the dry-spinning process on a large scale. Scanning electron microscopic images show that all formulations of as-spun fibers exhibit elliptical cross sections as well as dense morphologies. The structural evolution of the co-PI fiber induced by the high rolling speed and post-heat-drawing treatment was studied by means of thermogravimetric analysis, dynamic thermomechanical analysis, and two-dimensional wide-angle X-ray diffraction (2D WAXD). With increasing rolling speeds, glass transition temperatures ( Tgs) and thermal stabilities of as-spun fibers slightly decrease, which may be resulted from the disentanglement of entangled molecular chains under the large deformation and high-temperature heating atmosphere in the spinning column. 2D WAXD data indicate that both increasing rolling speeds and post-heat-drawing treatment are beneficial for getting a highly ordered structure along the meridian direction of the fibers. The fibers treated at 430°C exhibit outstanding mechanical properties, and the tensile strength and modulus reach 1.44 GPa and 48.69 GPa, respectively, at a drawing ratio of 2.8.
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Affiliation(s)
- Wenjun Tan
- Key Laboratory of High-Performance Fiber and Product, Ministry of Education, Shanghai, China
- College of Materials Science and Engineering, Donghua University, Shanghai, China
| | - Jie Dong
- Key Laboratory of High-Performance Fiber and Product, Ministry of Education, Shanghai, China
- College of Materials Science and Engineering, Donghua University, Shanghai, China
| | - Zhentao Li
- Key Laboratory of High-Performance Fiber and Product, Ministry of Education, Shanghai, China
- College of Materials Science and Engineering, Donghua University, Shanghai, China
| | - Dianbo Zhang
- Key Laboratory of High-Performance Fiber and Product, Ministry of Education, Shanghai, China
- College of Materials Science and Engineering, Donghua University, Shanghai, China
| | - Xin Zhao
- Key Laboratory of High-Performance Fiber and Product, Ministry of Education, Shanghai, China
- College of Materials Science and Engineering, Donghua University, Shanghai, China
| | - Qinghua Zhang
- Key Laboratory of High-Performance Fiber and Product, Ministry of Education, Shanghai, China
- College of Materials Science and Engineering, Donghua University, Shanghai, China
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Influence of molecular weight on scaling exponents and critical concentrations of one soluble 6FDA-TFDB polyimide in solution. JOURNAL OF POLYMER RESEARCH 2017. [DOI: 10.1007/s10965-017-1204-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Chen L, Long Z, Zhang Y, Wang S, Li Z, Guo S, Wang B. Modification of dry-spun Suplon polyimide fibers by mixed-acid oxidation and their effects on the properties of polypropylene-resin-based composites. J Appl Polym Sci 2017. [DOI: 10.1002/app.44932] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Le Chen
- Key Laboratory of Ecotextiles (Ministry of Education); Jiangnan University; Wuxi 214122 Jiangsu China
| | - Zhu Long
- Key Laboratory of Ecotextiles (Ministry of Education); Jiangnan University; Wuxi 214122 Jiangsu China
| | - Yifan Zhang
- College of Chemistry; Jilin University; Changchun 130012 Jilin China
| | - Shihua Wang
- Lianyungang Industry Investment Group Company; Limited; Lianyungang 222002 Jiangsu China
| | - Zhiqiang Li
- Lianyungang Industry Investment Group Company; Limited; Lianyungang 222002 Jiangsu China
| | - Shuai Guo
- Lianyungang Industry Investment Group Company; Limited; Lianyungang 222002 Jiangsu China
| | - Bin Wang
- State Key Laboratory of Pulp and Paper Engineering; South China University of Technology; Guangzhou 510640 Guangdong China
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Zhang E, Dai X, Dong Z, Qiu X, Ji X. Critical concentration and scaling exponents of one soluble polyimide—from dilute to semidilute entangled solutions. POLYMER 2016. [DOI: 10.1016/j.polymer.2016.01.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Comparison of different methods for determining the imidization degree of polyimide fibers. CHINESE JOURNAL OF POLYMER SCIENCE 2015. [DOI: 10.1007/s10118-016-1749-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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