| 초록 |
The phase transition behavior of side chain liquid crystalline polymers (LCPs), poly[oxy(octylsulfonylhexylthiomethyl)ethylene] (8S6EO), poly[oxy(tetradecyl-sulfonylmethyl)ethylene] (14SEO) and poly[oxy(hexadecylsulfonylmethyl)-ethylene] (16SEO), was investigated by using DSC, POM, synchrotron X-ray scattering and rheological measurements. In the case of 8S6EO, the presence of sulfone group located at intermediate position in side chain made it possible to obtain a highly ordered crystalline phase with lateral packing order in side chains. The scattering patterns completely disappeared in the isotropic state. On the other hand, 14SEO and 16SEO containing sulfone groups near the polar backbone showed the evident mesophase stability compared with the 8S6EO due to its amphiphilic character. Interestingly, it is clearly observed for both of them that a broad scattering, relating to the correlation hole peak due to the presence of dynamic density inhomogeneity in the disordered state, still persisted even above the Ti phase transition in contrast to the 8S6EO. We also investigated on the effect of alkyl side chains on phase behavior of LCP with 14SEO and 16SEO, which showed layer structures with the periodic undulation of backbone chains for 16SEO due to the increase in the length of hydrophobic alkyl side chains. |
