Session L36 - General Poster Session II.
POSTER session, Wednesday morning, March 22
Exhibit Hall, MCC
A series of polynorbornenes (PNBEs) with 1,4-bis[(3´-fluoro-4´-n-alkoxyphenyl)ethynyl] benzene mesogens (n = 9-12) laterally attached to the polymer backbone through a one-carbon spacer was synthesized by ring-opening metathesis polymerization of the corresponding norbornene-based monomers. Wide angle X-ray diffraction experiments demonstrate that the mesogens organize into the tilted layer structure of a smectic C phase at room temperature, and polarized light microscopy demonstrates that the highest temperature phase is a nematic phase. Upon heating above room temperature, the tilt angle of the smectic C phase of all of the PNBEs (n = 9 - 12) continuously decreases, especially at temperatures above 60°C. However, the smectic C phase of PNBE (n = 12) transforms to a smectic A phase at 85 °C, whereas the smectic C phase of the PNBEs (n = 9 - 11) transforms to a N phase. The phase transformation between the smectic C and the smectic A phases is characterized by a second-order transition.