High-T g Polyimide Matrix Composites via Backbone Ethynyl Crosslinking: Preparation and Short-Term High-Temperature Performance.
Saved in:
| Title: | High-T g Polyimide Matrix Composites via Backbone Ethynyl Crosslinking: Preparation and Short-Term High-Temperature Performance. |
|---|---|
| Authors: | Sun, Jinsong1 (AUTHOR), Huang, Chengyu1,2 (AUTHOR), Li, Shengxiong1,2 (AUTHOR), Liu, Hansong1,2 (AUTHOR), Yao, Lei1 (AUTHOR), Zhang, Peng1 (AUTHOR) lisx057@avic.com, Zhong, Xiangyu1 (AUTHOR), Bao, Jianwen1 (AUTHOR) baojianwen@sohu.com |
| Source: | Polymers (20734360). May2026, Vol. 18 Issue 9, p1016. 13p. |
| Subjects: | Glass transition temperature, Crosslinking (Polymerization), Aerospace materials, Thermal stability, Composite materials, Thermomechanical properties of metals, Polymer networks, Carbon fiber-reinforced plastics |
| Abstract: | Carbon fiber-reinforced polyimide composites are critical for aerospace applications in high-temperature environments of 300–500 °C. However, conventional PMR-15- and PEPA-terminated polyimides are limited by their insufficient glass transition temperatures (Tg) and low crosslinking densities. This study proposes a reactive backbone construction strategy by employing 4,4′-(ethyne-1,2-diyl)diphthalic anhydride (EBPA) as a difunctional monomer copolymerized with asymmetric 2,3,3′,4′-biphenyl tetracarboxylic dianhydride (α-BPDA) and 4,4′-oxydianiline to synthesize polyimide resins containing both backbone ethynyl and terminal phenylethynyl groups. The effects of EBPA content on the curing behavior, thermomechanical properties, and elevated temperature mechanical performance were systematically investigated. The incorporation of EBPA significantly elevated Tg from 378 °C to 486 °C. Compared to the EBPA-0 control, the optimized EBPA-2 composite exhibited 7.3% and 3.6% improvements in room temperature flexural strength and modulus, respectively. Notably, at 400 °C, EBPA-2 demonstrated retention rates of 69.9%, 93.7%, and 61.6% for flexural strength, flexural modulus, and interlaminar shear strength, exceeding EBPA-0 by 16.9, 8.9, and 18.6 percentage points. SEM analysis confirmed the effective suppression of interfacial debonding at elevated temperatures. These findings elucidate the structure–property relationships between molecular structure, Tg, and short-term high-temperature mechanical retention, providing a promising resin matrix for advanced aerospace carbon fiber composites. [ABSTRACT FROM AUTHOR] |
| Copyright of Polymers (20734360) is the property of MDPI and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
|
Full text is not displayed to guests.
Login for full access.
|
|
| Abstract: | Carbon fiber-reinforced polyimide composites are critical for aerospace applications in high-temperature environments of 300–500 °C. However, conventional PMR-15- and PEPA-terminated polyimides are limited by their insufficient glass transition temperatures (Tg) and low crosslinking densities. This study proposes a reactive backbone construction strategy by employing 4,4′-(ethyne-1,2-diyl)diphthalic anhydride (EBPA) as a difunctional monomer copolymerized with asymmetric 2,3,3′,4′-biphenyl tetracarboxylic dianhydride (α-BPDA) and 4,4′-oxydianiline to synthesize polyimide resins containing both backbone ethynyl and terminal phenylethynyl groups. The effects of EBPA content on the curing behavior, thermomechanical properties, and elevated temperature mechanical performance were systematically investigated. The incorporation of EBPA significantly elevated Tg from 378 °C to 486 °C. Compared to the EBPA-0 control, the optimized EBPA-2 composite exhibited 7.3% and 3.6% improvements in room temperature flexural strength and modulus, respectively. Notably, at 400 °C, EBPA-2 demonstrated retention rates of 69.9%, 93.7%, and 61.6% for flexural strength, flexural modulus, and interlaminar shear strength, exceeding EBPA-0 by 16.9, 8.9, and 18.6 percentage points. SEM analysis confirmed the effective suppression of interfacial debonding at elevated temperatures. These findings elucidate the structure–property relationships between molecular structure, Tg, and short-term high-temperature mechanical retention, providing a promising resin matrix for advanced aerospace carbon fiber composites. [ABSTRACT FROM AUTHOR] |
|---|---|
| ISSN: | 20734360 |
| DOI: | 10.3390/polym18091016 |
