| 초록 |
Polyurethane-urea are industrially important polymers with various structures and wide applications. Liquid-crystalline polyurethane-urea were prepared using two step method from methoxypolylene glycol (Mw=550, 2000g/mol) (mPEG), diphenymethane-4,4’-diisocyanate (MDI), and 4,4’-azodianilline. In the 1st step, 4,4’-azodianilline and MDI were reacted to form NCO-terminated mesogenic unit. In the 2nd step, the mesogenic unit was reacted with the excess amount of mPEG to form OH-terminated polyurethane-urea. The liquid-crystalline properties of liquid-crystalline polyurethane-urea were investigated by DSC, POM, thermal analysis, tensile strength. After preparing liquid-crystalline polyurethane-urea, liquid-crystalline polyurethane-urea were self-assembled on the glass. First, 3-aminopropyl-trimethyoxysilane (APTMS) was coated with monolayer on the glass. Next, liquid-crystalline polyurethane-urea were assembled at an interval of APTMS. The self-assembly properties of liquid-crystalline polyurethane-urea were investigated SEM, AFM. The effect of reversible photo (UV) and thermal isomerization of 4,4’-azodianilline in mesogenic unit on liquid crystal behavior of the polyurethane-urea will be discussed. |
