LC POLY(IMIDE)S .4. POLY(ESTER IMIDE)S DERIVED FROM NAPHTHALENE-1,4,5,8-TETRACARBOXYLIC ACID, OMEGA-AMINO ACIDS AND ALPHA,OMEGA-DIHYDROXY-ALKANES AND THEIR LOW-MOLECULAR-WEIGHT MODELS

Two series of poly(ester imide)s were synthesized from α,ω-dihydroxyalkanes. The first series was derived from N,N′-bis(carboxymethylene)naphthalene-1,4,5,8,-tetracarboxylic imide and the second from N,N′-bis(carboxypentamethylene)naphthalene-1,4,5,8-tetracarboxylic imide. These poly(ester imide)s were prepared by transesterification of the dimethylesters with the corresponding diols. The poly(ester imides)s were characterized by elemental analyses, inherent viscosities, DSC measurements, WAXS measurements, microscopic observation with crossed polarizers and thermomechanical analyses. All poly(ester imide)s possess a layered supermolecular structure in the solid state but they do not form a fluid mesophase. The high degree of order in the smectic solid state is demonstrated by WAXS measurements and thermomechanical analyses which yield heat-distortion temperatures related to the melting process. WAXS measurements conducted with synchrotron radiation at variable temperature indicate that low molecular weight model compounds also do not form a mobile smectic A or C phase but undergo a solid transition, between two crystalline smectic phases. © 1990.