Synthesis and characterization of new soluble polyamides from 1,1-bis[4-(4-carboxyphenoxy)phenyl]-4-tert-butylcyclohexane and various diamines

A new dicarboxylic acid monomer, 1,1-bis [4-(4-carboxyphenoxy)phenyl]-4-ter t-butylcyclohexane, bearing a pendent tert-butylcyclohexylidene group was p repared in three steps from 4-tert-butylcyclohexanone. The monomer was reac ted with various diamines to produce a series of new polyamides with triphe nyl phosphite and pyridine as condensing agents. These polyamides were prod uced with inherent viscosities of 0.74 to 1.02 dL g(-1). All the polymers w ere characterized by X-ray diffraction that revealed this amorphous nature. These polymers exhibited excellent solubility in a variety of solvents. Al most all the polymers could be dissolved in N-methyl-2-pyrrolidinone, N,N-d imethylacetamide (DMAc), N,N-dimethylformamide, dimethyl sulfoxide, pyridin e, and even in tetrahydrofuran and cyclohexanone. These polymers showed gla ss-transition temperatures between 223 and 256 degrees C and decomposition temperatures at 10% weight loss ranging from 468 to 491 degrees C and 469 t o 498 degrees C in nitrogen and air atmospheres, respectively. Transparent, tough, and flexible films of these polymers were cast from the DMAc soluti ons. These polymer films had tensile strengths ranging from 76 to 99 MPa, e longations at break from 7 to 19%, and initial moduli from 2.1 to 2.7 GPa. (C) 2000 John Wiley & Sons, Inc.