| 초록 |
Thermal liquid crystalline polymer (TLCP) of the rigid moiety terephthaloyl bis(4-oxybenzoyl) (triad) with butylene terephtalate flexible unit was solution-polymerized by a polycondensation method, and its sulfonated TLCP ionomers were prepared by subsequent sulfonation. The equivalent molecular weights of the polymer chains after sulfonation were found to be ca. 3580, 2900, and 2190. It was found that, upon the sulfonation, DSC melting and crystallization peaks of the TLCP shifted to slightly lower temperatures and typical optical textures found in cross polarized-light microscopy (i.e. 2- and 4-brush) became smaller. When the acid groups of the sulfonated TLCP was neutralized with Na, it was observed that the melting peak split into two and shifted to lower temperatures. It was also found that the crystallization peak and the optical textures vanished. These imply that the sulfonation introduced ionic characters to the TLCP polymer successfully; however, the sulfonation reduced the liquid crystalline characters of the TLCP significantly. |
