Structure to Properties Relations of Polyimide Foams Derived from Various Dianhydride Components

This work focuses on the influence of chain structure on properties such as the structural, thermal, morphological, and mechanical properties of polyimide foams (PIFs) which were prepared by polyester ammonium salt powder foaming process. Results showed that the melt viscosity of PEAS is affected by the structure of dianhydrides, which can greatly determine the foaming process, cell structure, and final properties of PIFs. PIF which was derived from 3,3′,4,4′-benzophenonetetracarboxylic dianhydride and 4,4′-diaminodiphenylmethane exhibited the highest compressive strength (0.374 MPa-RT, 0.194 MPa-200 °C) and compressive modulus (9.24 MPa-RT, 7.37 MPa-200 °C). All PIFs exhibited excellent thermal stability as the initial thermal decomposition temperature reached as high as 544 °C. In addition, the thermal conductivity of the as-prepared PIFs fell in a range of 38–42 mW m^–1K^–1, which show potential applications in areas of aerospace, aeronautics, marine use, and transportation among others.