P. Masson et al., SYNTHESIS AND CHARACTERIZATION OF CRYSTALLINE POLY(ETHYLENEIMINE)S WITH MESOGENIC SIDE-CHAINS FORMING LIQUID-CRYSTALS ON QUATERNIZATION, Macromolecular chemistry and physics, 195(4), 1994, pp. 1199-1212
The synthesis and thermal properties of a new type of side-chain liqui
d-crystalline polysalts are described. The polymers are first obtained
by partial or complete alkylation of a linear poly(ethyleneimine) wit
h 6-(4-methoxy-4'-biphenylyloxy)hexyl bromide or 12-(4-methoxy-4'-biph
enylyloxy)dodecyl bromide. In a second step, polysalts are prepared by
partial or complete quaternization with acyl bromide or dimethyl sulf
ate. Differential scanning calorimetry, polarizing optical microscopy
and X-ray diffraction experiments show that the polymers and copolymer
s alkylated with the mesogenic groups are all crystalline. When quater
nized, they exhibit thermotropic smectic A phases. This behaviour conf
irms the smectogenic function of the ammonium units located in the bac
kbone, as already observed with poly(4-vinylpyridinium) salts.