The liquid crystalline behavior of anisotropic solutions in 100% sulphuric acid ofaromatic copolyamide obtained by low-temperature solution copolycondensation of tere-phthalic acid chloride (TPC)

p-phenylene diamine (PPD) and 4

4'-diamino-diphenylether(DAPE) has been studied by optical microscopy and X-ray diffeaction. The effects ofinherent viscosity

concentration of copolyamide in sulphuric acid

the content of the thirdmonomer (DAPE) and sequence distribution of copolyamide on the critical concentration

isotropic temperature

phase diagram and texture of liquid crystal were investigated.The schlieren texture was observed and the results of X-ray diffraction indicate that the concentrated solutions of copolyamide exhibit nematic liquid crystalline behavior.