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Ionically Grafted Side‐Chain Polymers: Blends of an Acid‐Functionalized Mesogen with Poly(ethylene imine)
Author(s) -
Brandys F. A.,
Masson P.,
Guillon D.,
Bazuin C. G.
Publication year - 2001
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/1521-3935(20010301)202:6<856::aid-macp856>3.0.co;2-g
Subject(s) - mesogen , polymer chemistry , bilayer , lamellar structure , polymer , phase (matter) , chemistry , side chain , carboxylate , stoichiometry , salt (chemistry) , materials science , crystallography , organic chemistry , membrane , biochemistry , liquid crystalline
An acid‐functionalized dialkoxy biphenyl mesogen (LC‐4,6A) was mixed to varying proportions with linear poly(ethylene imine) (PEI). Infrared analysis indicates that extensive complexation occurs in these blends, primarily via proton transfer that leads to ion‐pair interactions, probably with acid‐salt structures present nearer stoichiometric compositions. This analysis also shows that carboxylate bands are intense only for blends with very low acid group content, where acid‐salt structures are essentially absent. An ordered phase of the smectic E type, similar to that of pure LC‐4,6A, is obtained in the blends. It melts at higher temperatures for the near‐stoichiometric blends than for pure LC‐4,6A. A primarily single‐layered phase is obtained in solution‐prepared samples. It is metastable, and transforms slowly and irreversibly into a bilayer phase at higher temperatures, beginning well before the melting temperature. The lamellar thickness is independent of composition, suggesting that the complexing sites are distributed along the polymer chain in blocky fashion. Single‐ and bilayer models are proposed where the latter can be obtained from the former by simple translational motion of the complexed segments.