Preparation and characterization of matrix-graded polyimide composite along thickness direction

• Published in: Hang kong cai liao xue bao Vol. 42; no. 3; pp. 55 - 62
• Main Authors: Ni, Hongjiang, Li, Jun, Xing, Yu, Zhang, Daijun, Chen, Xiangbao
• Format: Journal Article
• Language: Chinese
• Published: Beijing Beijing Institute of Aeronautical Materials 01.06.2022; Journal of Aeronautical Materials
• Subjects: composites; Glass transition temperature; matrix gradation along thickness direction; Polyimide resins; polyimides; Process parameters; Resin transfer molding; resin-transfer-molding (rtm); Rheological properties; Rheology; Surface layers; Thermal resistance; Thermal stability; Thermogravimetry; Thickness; Viscosity
• ISSN: 1005-5053
• DOI: 10.11868/j.issn.1005-5053.2022.000023

A resin-transfer-molding (RTM) polyimide resin, RTM-PI, was developed, and the matrix-graded polyimide composite along thickness directions was fabricated with RTM processing. The matrix-graded composite was composed of surface layers with polyimide matrix having high thermal stability, and core layers with RTM-PI matrix. The RTM processing parameters were established based on thermogravimetry, rheology and curing data of PI resins. The results show that RTM-PI resin exhibits the properties of low viscosity, super long processable time, and high thermal resistance. The lowest viscosity is below 0.1 Pa·s, processable time is longer than 300 min, and glass-transition-temperature reaches 445 ℃. The internal quality of the matrix-graded polyimide composite along thickness direction is excellent, and the reduction of mass loss after the thermal ageing at 350 ℃ for 100 h is more than 48% lower than that of the pure RTM-PI composite.