SYNTHESIS AND PROPERTIES OF OPTICALLY-ACTIVE AROMATIC POLYIMIDES DERIVED FROM OPTICALLY PURE 1,1'-BI-2-NAPHTHOL

A series of new optically active aromatic polyimides containing axiall y dissymmetric 1,1'-binaphthalene-2,2-diyl units were prepared from op tically pure (R)-(+)-or -2,2'-bis(3,4-dicarboxyphenoxy)-1,1'-binaphtha lene dianhydrides and various aromatic diamines via a conventional two -step procedure that included ring-opening polycondensation and chemic al cyclodehydration. The optically pure isomer of dianhydride was prep ared by a nucleophilic substitution of optically pure (R)-(+)or (S)-(- )1,1'-bi-2-naphthol with 4-nitrophthalonitrile in aprotic polar solven t and subsequent hydrolysis of the resultant tetranitrile derivatives, followed by the dehydration of the corresponding tetracarboxylic acid s to obtain the dianhydrides. These polymers were readily soluble in c ommon organic solvents such as N,N-dimethylacetamide, N-methyl-2-pyrro lidone, and m-cresol, etc., and have glass transition temperatures of 251-296 degrees C, and 5% weight loss occurs not lower than 480 degree s C. The specific rotations of the optically active polyimides ranged from +196 degrees to +263 degrees, and the optical stability and chiro ptical properties of them were also studied. (C) 1997 John Wiley & Son s, Inc.