Preparation and Properties of Lightweight Heat‐Resistant Porous Continuous Polyimide Fiber Composites

ABSTRACT The development of new lightweight materials that are also highly durable and heat‐resistant is one of the most pressing issues in areas such as aircraft and shipbuilding. In this work, highly heat‐resistant polyimide (PI) foam composites were obtained from prepolymers based on dianhydrides (3,3′,4,4′‐benzophenone tetracarboxylic dianhydride (BTDA), 4,4′‐oxydiphthalic anhydride (ODPA)), diamine (4,4′‐methylenedianiline (MDA)), and Arimid polyimide fibers. It has been shown that synthesized materials have low density (≈0.2 g/cm 3 ) due to a porous structure and high durability due to the reinforcement with polyamide fiber. High glass transition temperature (≈260°C) in combination with high thermal stability (the temperature of the beginning of mass loss of the prepared foam composites exceeds 550°C) facilitates the preservation of mechanical properties of such composites at both low and elevated temperatures. Excellent mechanical properties and high thermal stability of the developed lightweight polyimide foam composites together with their exceptional flame retardancy make them promising materials for application in advanced technologies, such as aircraft and shipbuilding industries, aerospace engineering, and building in northern regions.