Properties of Novel Fibrous Foam Composites Based on Nano‐Modified Prepolymers

ABSTRACT Foaming prepolymer compositions were synthesized on the basis of 3,3′,4,4′‐benzophenone tetracarboxylic dianhydride (BTDA) esterified with ethanol, 4,4′‐methylenedianiline (MDA), and various amounts of single‐walled carbon nanotubes (SWCNT). These prepolymers modified with nanotubes were used as foaming binding agents to obtain new polyimide composite materials (foam composites) reinforced with carbon‐containing polyimide fibers Arimid. The results of comparative studies of thermal and mechanical properties of the obtained nano‐modified foam composites are presented. The investigated samples demonstrated high thermal stability (the onset of mass loss was observed at 546°C–555°C) and low density (0.23–0.24 kg/m 3 ); the values of flexural modulus of elasticity varied from 147 to 260 kPa, the longitudinal and transverse compression moduli were equal to 35–70 and 5–7 MPa, respectively. It was shown that the prepared foam composites were fire resistant. The samples retained their characteristics at −50°C without any increase in brittleness or deterioration of their mechanical properties, which makes them suitable for use in building structures operated in northern regions.