Synthesis of cardo containing asymmetric poly(ether-naphthalimide-phthalimide)s

A series of cardo based asymmetric polyimides containing bulky rigid naphthalimide and phthalimide groups were prepared from asymmetric monomer bishaloimide and bisphenols by solution polycondensation. Bishalo(naphthalimide-phthalimide) monomers containing different terminal leaving groups (Cl, F, NO 2 ) were synthesized, and the reactivity difference of these monomers was compared for the successful synthesis of polyimides. The inherent viscosities of the polyimides were in the range 0.51 − 0.60 dL g −1 in N -methyl-2-pyrrolidone at 30 °C. These polyimides demonstrated good organosolubility and mechanical properties with tensile strengths of 93 − 120 MPa, tensile moduli of 3.5 − 5.3 GPa and elongations at break of 2.8% − 4.3%. The polyimides showed high glass transition temperatures ( T g ) ranging from 330 to 363 °C. The 10% weight loss ( T 10% ) of asymmetric polyimides reached 436 − 500 °C in nitrogen and 417 − 476 °C in air. The water uptake of the polyimides was in the range 0.35% − 0.72%. © 2017 Society of Chemical Industry