LC polyimides. XXXVI. Poly(ester imide)s derived from N,N '-bis(4-hydroxyphenyl)biphenyl-3,3 ',4,4 '-tetracarboxylic diimide and aliphatic dicarboxylic acids

A new mesogenic monomer was prepared from biphenyl-3,3',4,4' -tetracarboxyl ic dianhydride and 4-aminophenol followed by the acylation of OH groups wit h propionic anhydride. This diphenol propionate was polycondensed by transe sterification with decane-1,10-dicarboxylic acid, dodecane-1,12-dicarboxyli c acid, and eicosane-1,20-dicarboxylic acid or with equimolar mixtures of t wo dicarboxylic acids. The resulting poly(ester imide)s were characterized by elemental analyses, H-1 NMR spectra, inherent viscosities, DSC measureme nts, optical microscopy, and X-ray measurements with synchrotron radiation at variable temperatures. An enantiotropic smectic A phase in the molten st ate and a crystalline smectic E (or H) phase in the solid state were found in all cases. (C) 2000 John Wiley & Sons, Inc.