비페닐 구조를 가지는 액정폴리머의 합성과 특성 = Synthesis and Characterization of Thermotropic Liquid Crystalline Polyurethanes with Biphenyl Moiety

다국어 초록 (Multilingual Abstract)

A series of thermotropic polyurethanes containing biphenyl units was synthesized by polyaddition reaction of diisocyanates such as 2,6-tolylene diisocyanate, 2,5-tolylene diisocyanate, 2,4-tolylene diisocyanate, and 1,4-phenylene diisocyanate, and hexamethylene diisocyanate with 4,4'-Bis(9-hydroxynonoxy)biphenyl (BP9). Structures of the monomer and the corresponding polymers were identified using FT-IR and ^(1)H-NMR spectroscopies. Their phase transition temperatures and thermal stability were also investigated by differential scanning calorimetry and optical polarizing microscopy. 4,4'-bis(9-hydroxynonoxy)biphenyl exhibited a smectic type mesophase. Mesophase was found for all synthesized liquid crystalline polyurethanes except 1,4-PDI/BP9 based polyurethane.