SYNTHESES AND PROPERTIES OF POLYAMIDES FROM ETHER DIACID HAVING THE SPIROBICHROMAN UNIT

A novel hexamethylspirobichroman (HMSBC) unit-containing dicarboxylic acid, oxy)-4,4,4',4',7,7'-hexamethyl-2,2'-spirobichroman (3), was deri ved from nucleophilic substitution of p -fluorobenzonitrile with the p henolate ion of roxy-4,4,4',4',7,7'-hexamethyl-2,2'-spirobichroman (1) , followed by alkaline hydrolysis of the intermediate bis(ether nitril e). Using TPP and pyridine as condensing agents, a series of polyamide s with inherent viscosities in the range of 0.82-1.14 dL/g were prepar ed by the direct polycondensation of dicarboxylic acid 3 with various aromatic diamines. All the obtained polymers were noncrystalline and s oluble in various organic solvents such as N,N-dimethylacetamide (DMAc ) and N-methyl-2-pyrrolidone (NMP). Except for the polymer derived fro m benzidine, the other polyamides could be solution cast into transpar ent and tough films, and their tensile strengths, elongations at break , and tensile moduli were in the range of 56-76 MPa, 4-59%, and 1.6-2. 0 GPa, respectively. These polyamides had glass transition temperature s in the range of 183-200 degrees C with 10% weight loss above 420 deg rees C. (C) 1997 John Wiley & Sons, Inc.