Synthesis and characterization of norbornane-containing cardo polyamides

A new diamine, 2,2-bis [4-(4-aminophenoxy)phenyl] norbornane (BAPN), containing both ether and norbornane cardo groups, was synthesized in three steps started from norcamphor. A series of cardo polyamides were obtained by the direct polycondensation of BAPN and various aromatic dicarboxylic acids in N-methyl-2-pyrrolidinone (NMP) using triphenyl phosphite and pyridine as condensing agents. Polyamides had inherent viscosities in the range of 0.82-1.58 dL g(-1), and were readily soluble in polar aprotic solvents such as NMP, N,N-dimethylacetamide (DMAc) and N,N-dimethylformamide and dimethyl sulfoxide. These polymers were cast in DMAc solution into transparent, flexible, and tough films that were further characterized by X-ray and mechanical analysis. All the polymers were amorphous, and the polyamide films had a tensile strength range of 71-89 MPa, an elongation at break range of 5-9%, and a tensile modulus range of 2.0-2.3 GPa. Polyamides showed glass transition temperatures in the range of 256-296 degrees C as measured by DSC and thermogravimetric analysis indicated no weight loss below 450 degrees C in nitrogen and air atmosphere. (C) 1999 John Wiley & Sons, Inc.