| Abstract: | Copolycondensation of isophthalic (IPA) and terephthalic (TPA) acids, methylhydroquinone (MeHQ), and aromatic diamines with diphenyl chlorophosphate (DPCP) in pyridine were investigated. The resulting copoly(ester-amides) showed optical anisotropy, which was discussed in terms of the ester and amide sequence lengths in the copolymers. The temperature above which the anisotropy was observed varied in the 225 to 300°C range by changing addition time of a mixture of MeHQ and diamines, initial reaction with MeHQ, and the further reaction with diamines. |
