Synthesis and characterization of new organosoluble polyamides derived from bis[4-(4-carboxyphenoxy) phenyl]diphenylmethane

A new dicarboxylic acid containing a diphenylmethylene linkage, bis[4-(4-ca rboxyphenoxy)phenyl] diphenylmethane (BCAPD), was prepared from bis(4-hydro xphenyl)diphenylmethane and p-fluorobenzonitrile via an aromatic nucleophil ic substitution reaction followed by hydrolysis. A series of novel polyamid es were prepared by the direct polycondensation of BCAPD and various aromat ic diamines. The polymers were produced with moderate to high inherent visc osities of 0.80-0.85 dL g(-1). Nearly all the polymers were readily soluble in polar solvents such as N-methyl-2-pyrrolidinone, N,N-dimethylacetamide, N,N-dimethylformamide, and dimethyl sulfoxide, in less polar solvents such as pyridine and cyclohexanone, and in tetrahydrofuran. All the polymers we re amorphous, and the polyamide films had a tensile strength and a tensile modulus greater than 80 MPa and 2.0 GPa, respectively. These polyamides had glass-transition temperatures between 249 and 274 degreesC, and their temp eratures at a 10% weight loss were 477-538 and 483-540 degreesC in nitrogen and air atmospheres, respectively. (C) 2001 John Wiley & Sons, Inc.