Polyimide composite containing biphenyl structure

The ultra-high temperature composite was fabricated based on the polyimide composite containing biphenyl structure as the matrix resin and carbon fiber AS4. The rheology of polyimide precursor prepared by a modified polymerization of monomeric reactants (MPMR) approach was studied. The flexural strength and the flexural modulus of the composite at RT and 371°C are 1190 MPa, 763 MPa and 121 GPa, 116 GPa, respectively. The shear strength of the composite at RT and 371°C are 42 MPa and 26 MPa. The mechanical property of the composite at the temperature of 371°C can reach half of its mechanical property at room temperature. The glass transition temperature is up to 472°C by DMA. The weight losses of the resin and composite at 371°C for 100 h are 1.9% and 2.0%.