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A series of novel liquid crystalline monomers based on N-
substituted and 3-substituted pyrrole with varying the spacer
length of alkylene and pentyl- or cyano- tail group on biphenyl
mesogenic cores were synthesized. These monomers were
polymerized by electrochemical method to yield conjugative
polypyrrole with biphenyl-based mesogenic cores as the side
groups.All the eight prepared monomers can be classified into
two series; the first series is the N-substituted pyrrole: MPe-
P-n (R = C5H11, n = 6,8 and 10) and MCN-P-n (R = CN, n = 6,8 and
10); the second series is the 3-substituted pyrrole: MAC-P (R =
C5H11, n = 6) and MACCN-P (R = CN, n = 6). All the monomers,
MCN-P-n and MACCN-P with cyano- tail groups exhibited nematic
mesophase. In contrast, all the monomers, MPe-P-n and MAC-P with
pentyl- tail groups showed smectic mesophase. Moreover, the
monomer with cyano- group showed higher Ti than the respective
monomer with pentyl- tail group.The polymers were formed
electrochemically by cyclic voltammetry. For the reason of their
insoluble and infusible. Structure of the polymers could only be
determined by UV and IR spectra. Comparison with the current
response indicated that N-substituted pyrrole forms
electroactive polymer about 40 times faster than 3-substituted
pyrrole. It was reversible and diffusion-controlled during
polymerization. However, comparison with the time maintain
electroactivity of polymer film showed that 3-substituted
pyrrole was longer than N-substituted pyrrole.
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