The liquid crystalline behavior of anisotropic solutions in 100% sulphuric acid of aromatic copolyamide obtained by low-temperature solution copolycondensation of terephthalic acid chloride (TPC), p-phenylene diamine ...The liquid crystalline behavior of anisotropic solutions in 100% sulphuric acid of aromatic copolyamide obtained by low-temperature solution copolycondensation of terephthalic acid chloride (TPC), p-phenylene diamine (PPD) and 4, 4'-diamino-diphenylether (DAPE) has been studied by optical microscopy and X-ray diffraction. The effects of inherent viscosity, concentration of copolyamide in sulphuric acid, the content of the third monomer (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.展开更多
The synthesis and phase behavior of a series of 4'-alkyloxy -4-hydroxy biphenyls were discribed.The effects of reaction conditions on the yields of products were investigated.The characterizations of thermotropic ...The synthesis and phase behavior of a series of 4'-alkyloxy -4-hydroxy biphenyls were discribed.The effects of reaction conditions on the yields of products were investigated.The characterizations of thermotropic liquid crystalline products for the type and thermal properties are discussed through the use of differential scanning calorimetry,polarizing microscopy.展开更多
文摘The liquid crystalline behavior of anisotropic solutions in 100% sulphuric acid of aromatic copolyamide obtained by low-temperature solution copolycondensation of terephthalic acid chloride (TPC), p-phenylene diamine (PPD) and 4, 4'-diamino-diphenylether (DAPE) has been studied by optical microscopy and X-ray diffraction. The effects of inherent viscosity, concentration of copolyamide in sulphuric acid, the content of the third monomer (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.
文摘The synthesis and phase behavior of a series of 4'-alkyloxy -4-hydroxy biphenyls were discribed.The effects of reaction conditions on the yields of products were investigated.The characterizations of thermotropic liquid crystalline products for the type and thermal properties are discussed through the use of differential scanning calorimetry,polarizing microscopy.
