Five series of novel polyurethanes were synthesized by the polyaddition reaction of diisocyanates: 2,6-tolylene diisocyanate (2,6-TDI), 2,5-tolylene diisocyanate (2,5-TDI), 2,4-tolylene diisocyanate (2,4-TDI), and 1,4-phenylene diisocyanate (1,4-PDI), hexamethylene diisocyanate (HDI) with 4,4`-Bis(7-hydroxyheptoxy) biphenyl (BP7). 4,4`-bis(7-hydroxyheptoxy) biphenyl exhibited a smectic type mesophase. All synthesized liquid crystalline polyurethanes except 1,4-PDI/BP7 exhibit liquid crystalline behavior. The structures and the thermal properties of polyurethanes were studied by using FT-IR and ^1H NMR spectroscopy, DSC measurements and a polarizing microscope equipped with a heating stage.

다섯 종류의 새로운 형태의 액정성 폴리우레탄을 4,4`-bis(7-hydroxyheptoxy)biphenyl (BP7)와 2,6-tolylene diisocyanate (2,6-TDI), 2,5-tolylene diisocyanate (2,5-TDI), 2,4-tolylene diisocyanate (2,4-TDI), 1,4-phenylene diisocyanate (1,4-PDI) 및 hexamethylene diisocyanate (HDI)의 중부가 반응에 의해 합성하였다. 단량체 BP7은 스멕틱상을 형성하였으며 1.4PDI/BP7을 제외한 나머지 폴리우레탄에서는 모두 액정성을 나타내었다. 생성된 폴리우레탄의 구조는 IR과 ^1H NMR 스펙트럼에 의해 확인하였고 열적 성질은 DSC와 편광현미경으로 관찰하였다.