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Sivaev IB, Anufriev SA, Shmalko AV. How substituents at boron atoms affect the CH-acidity and the electron-withdrawing effect of the ortho-carborane cage: A close look on the 1H NMR spectra. Inorganica Chim Acta 2022. [DOI: 10.1016/j.ica.2022.121339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Toughening effect of self-assembled thermoplastic particles on phthalonitrile containing benzoxazine and improved mechanical properties in the presence of fibers reinforcement. POLYMER 2022. [DOI: 10.1016/j.polymer.2022.125355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Improved Melt Processabilities of Thermosetting Polyimide Matrix Resins for High Temperature Carbon Fiber Composite Applications. Polymers (Basel) 2022; 14:polym14050965. [PMID: 35267791 PMCID: PMC8912466 DOI: 10.3390/polym14050965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 02/22/2022] [Accepted: 02/22/2022] [Indexed: 11/29/2022] Open
Abstract
With the goal of improving processability of imide oligomers and achieving of high temperature carbon fiber composite, a series of Thermosetting Matrix Resin solutions (TMR) were prepared by polycondensation of aromatic diamine (3,4′-oxybisbenzenamine, 3,4-ODA) and diester of biphenylene diacid (BPDE) using monoester of 4-phenylethynylphthalic acid (PEPE) as end-capping agent in ethyl alcohol as solvent to afford phenylethynyl-endcapped poly(amic ester) resins with calculated molecular weight (Calc’d Mw) of 1500–10,000. Meanwhile, a series of reactive diluent solutions (RDm) with Calc’d Mw of 600–2100 were also prepared derived from aromatic diamine (4,4′-oxybisbenzenamine, 4,4-ODA), diester of asymmetrical biphenylene diacid (α-BPDE) and monoester of 4-phenylethynylphthalic acid (PEPE) in ethyl alcohol. Then, the TMR solution was mixed with the RDm solution at different weight ratios to afford a series of A-staged thermosetting blend resin (TMR/RDm) solutions for carbon fiber composites. Experimental results demonstrated that the thermosetting blend resins exhibited improved melt processability and excellent thermal stability. After being thermally treated at 200 °C/1 h, the B-staged TMR/RDm showed very low melt viscosities and wider processing window. The minimum melt viscosities of ≤50 Pa·s was measured at ≤368 °C and the temperature scale at melt viscosities of ≤100 Pa·s were detected at 310–390 °C, respectively. The thermally cured neat resins at 380 °C/2 h showed a great combination of mechanical and thermal properties, including tensile strength of 84.0 MPa, elongation at breakage of 4.1%, and glass transition temperature (Tg) of 423 °C, successively. The carbon fiber reinforced polyimide composite processed by autoclave technique exhibited excellent mechanical properties both at room temperature and 370 °C. This study paved the way for the development of high-temperature resistant carbon fiber resin composites for use in complicated aeronautical structures.
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Liu C, Qiao Y, Jia H, Li N, Chen Y, Jian X. Improved mechanical properties of basalt fiber/phthalonitrile composites modified by thermoplastic Poly(phthalazinone ether nitrile)s. POLYMER 2021. [DOI: 10.1016/j.polymer.2021.123947] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Xu L, He Y, Ma S, Hui L, Jia Y, Tu Y. Effects of aging process and testing temperature on the open-hole compressive properties of a carbon fiber composite. HIGH PERFORM POLYM 2020. [DOI: 10.1177/0954008319897291] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The properties of T800 carbon fiber–epoxy composite specimens with a hole were studied in terms of mass change, scanning electron microscopy, glass transition temperature ( T g), heat-resistant temperature, Fourier-transform infrared (FTIR) spectroscopy, open-hole compressive strength at different temperatures, and stereomicroscopic observations after being subjected to hygrothermal aging and thermal-oxidative aging processes. FTIR spectra indicated that after hygrothermal aging at 70°C and 85% relative humidity (RH), chemical aging did not occur, whereas after thermal-oxidative aging at 190°C, the specimens exhibited chemical aging. The unaged specimens had a T g of 229°C and an extreme heat-resistant temperature T gmod of 184°C; after hygrothermal aging, the specimens had a T g and T gmod of 207°C and 143°C, respectively; and after thermal-oxidative aging, the specimens had a T g and T gmod of 252°C and 215°C, respectively. The effects of temperature on open-hole compressive strength were evaluated at room temperature of 23°C, 50°C, 100°C, 150°C, and 200°C. The compressive strengths of the specimens decreased after aging and with the increasing test temperature. At the highest test temperature, the unaged specimens, hygrothermal-aged, and thermal-oxidative-aged specimens retained over 73.7%, 65.5%, and 67.9%, respectively, of their compressive strength. Thus, the T800 carbon fiber–epoxy composite evaluated in this study exhibited good resistance to the effects of aging and high temperature. These results should be beneficial to the understanding of the long-term performance of composites.
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Affiliation(s)
- Liang Xu
- College of Electromechanical Engineering, Shenyang Aerospace University, Shenyan, China
| | - Yi He
- College of Electromechanical Engineering, Shenyang Aerospace University, Shenyan, China
| | - Shaohua Ma
- College of Electromechanical Engineering, Shenyang Aerospace University, Shenyan, China
| | - Li Hui
- Key Laboratory of Fundamental Science for National Defense of Aeronautical Digital Manufacturing Process, Shenyang Aerospace University, Shenyang, China
| | - Yaoxiong Jia
- College of Electromechanical Engineering, Shenyang Aerospace University, Shenyan, China
| | - Yiming Tu
- College of Electromechanical Engineering, Shenyang Aerospace University, Shenyan, China
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Xu L, He Y, Jia Y, Ma S, Hui L. Effects of thermal–oxidative aging on the mechanical properties of open-hole T800 carbon fiber/high-temperature epoxy composites. HIGH PERFORM POLYM 2019. [DOI: 10.1177/0954008319883691] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
T800 carbon fiber/high-temperature epoxy resin composites with holes were subjected to thermal–oxidative aging, and the effects of different aging temperatures and times on the composite properties were investigated. The mass loss, surface topography, open-hole tensile performance, fracture morphologies, dynamic mechanical properties, and infrared spectra were analyzed. The results showed that chemical aging did not occur with thermal–oxidative aging at 70°C and 130°C. However, chemical aging occurred at 190°C. At 70°C, 130°C, and 190°C, all samples showed a slight increase followed by a slight decrease and stabilization in the open-hole tensile strength. The open-hole tensile strength was maximized after 240 h aging at different temperatures; the open-hole tensile strength after 1920 h aging exceeded that of the unaged samples. All composites experienced through-hole failure. With aging, the glass transition temperature ( T g) was gradually increased and then decreased. After 960 h aging at different temperatures, T g was maximized.
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Affiliation(s)
- Liang Xu
- College of Electromechanical Engineering, Shenyang Aerospace University, Shenyang, China
| | - Yi He
- College of Electromechanical Engineering, Shenyang Aerospace University, Shenyang, China
| | - Yaoxiong Jia
- College of Electromechanical Engineering, Shenyang Aerospace University, Shenyang, China
| | - Shaohua Ma
- College of Electromechanical Engineering, Shenyang Aerospace University, Shenyang, China
| | - Li Hui
- Key Laboratory of Fundamental Science for National Defense of Aeronautical Digital Manufacturing Process, Shenyang Aerospace University, Shenyang, China
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Zhuo L, Tang S, Zhao K, Xie F, Bai Y. Green facile fabrication of polyimide by microwave‐assisted hydrothermal method and its decomposition dynamics. J Appl Polym Sci 2019. [DOI: 10.1002/app.48484] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Longhai Zhuo
- Shaanxi Collaborative Innovation Center of Industrial Auxiliary Chemistry and TechnologyShaanxi University of Science and Technology Xi'an 710021 China
| | - Shulin Tang
- College of Chemistry and Chemical EngineeringShaanxi University of Science and Technology Xi'an 710021 China
| | - Kaiyan Zhao
- College of Chemistry and Chemical EngineeringShaanxi University of Science and Technology Xi'an 710021 China
| | - Fan Xie
- College of Bioresources Chemical and Materials EngineeringShaanxi University of Science and Technology Xi'an 710021 China
| | - Yang Bai
- College of Chemistry and Chemical EngineeringShaanxi University of Science and Technology Xi'an 710021 China
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Li K, Zhou L, Wu S, Yu Q, Yang L. A facile synthesis of soluble polyimides with high glass transition temperature and excellent mechanical properties due to intermolecular hydrogen bonds. HIGH PERFORM POLYM 2019. [DOI: 10.1177/0954008319861141] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
An unsymmetrical heterocyclic diamine monomer containing proton donor (–NH–), 2-(4-aminophenyl)-5-aminobenzimidazole (PABZ), which can form hydrogen bond interactions with carbonyl functional group, was copolymerized with 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) and 2,2′-bis(trifluoromethyl)-4,4′-diaminobiphenyl (TFMB) through two-step synthetic methods to obtain a series of homo- and co-polyimide (PI). The corresponding homo- and co-PI both exhibited good solubility in aprotic polar solvents, such as N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N, N-dimethylformamide, pyridine, and dimethyl sulfoxide. In addition, the PI-containing PABZ units showed excellent tensile strength ranging from 83 to 164 MPa, 130–260% higher than 6FDA/TFMB homo-PIa films. These PIs, especially PABZ/6FDA, showed very high glass transition temperatures, 430°C.
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Affiliation(s)
- Ke Li
- College of Materials Science and Engineering, Sichuan University of Science and Engineering, Zigong, Sichuan, People’s Republic of China
| | - Lan Zhou
- College of Materials Science and Engineering, Sichuan University of Science and Engineering, Zigong, Sichuan, People’s Republic of China
| | - Simin Wu
- College of Materials Science and Engineering, Sichuan University of Science and Engineering, Zigong, Sichuan, People’s Republic of China
| | - Qiyu Yu
- College of Materials Science and Engineering, Sichuan University of Science and Engineering, Zigong, Sichuan, People’s Republic of China
| | - Long Yang
- State Key Laboratory of Environmental Friendly Energy Materials, School of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang, Sichuan, People’s Republic of China
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