Synthesis and Characterization of Thermotropic Liquid Crystalline Polyurethanes

액정폴리우레탄의 합성 및 특성

  • Published : 2009.09.30

Abstract

Four series of novel liquid crystalline polyurethanes were synthesized by the polyaddition reaction of diisocyanates such as 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) with 4,4'-bis(5-hydroxypentoxy)biphenyl (BP5). 4,4'-bis(5-hydroxypentoxy)biphenyl exhibited a smectic type mesophase. Mesophase was found for all synthesized liquid crystalline polyurethanes except 1,4-PDI/BP5. 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.

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