Journal of Applied Polymer Science, Vol.82, No.3, 577-583, 2001
Synthesis and characterization of a novel kind of thermotropic liquid crystalline poly(urea-ester)s based on bis(4 '-hydroxyphenyl)-tolyene-2,4-diurea
A new diphenol monomer bis(4 ' -hydroxy-phenyl)-tolyene-2,4-diurea was synthesized by reaction of 2,4-toylene diisocyanate with p-aminophenol in N,N-dimethylformamide (DMF). The product was characterized by elemental analysis (EA), differential scanning calorimetry (DSC), and H-1-NMR. And a novel kind of liquid crystalline poly(urea-ester)s were obtained by using this monomer. By using a polarizing microscope with hot stage (POM), wide-angle X-ray diffraction (WAXD) and small-angle X-ray diffraction (SAXD) the polymers were proven to be nematic liquid crystal. The result of DSC showed that the effect of the monomer composition on the melting point of poly(urea-ester)s was significant.
Keywords:liquid crystalline polymer;poly(urea-ester)s;bis(4 '-hydroxy-phenyl)-tolyene-2,4-diurea;nematic