Abstract:
Summary: Polymeric betaines containing long alkyl chains (C12H25, C13H27, C14H29,
C16H33 and C18H37) were synthesized by Michael addition reaction of alkylaminocrotonates
and methacrylic acid. They were characterized by FTIR, 13C NMR, DLS, TEM,
viscometry and zeta-potential measurements. In aqueous KOH and DMSO solutions
the hydrophobically modified polymeric betaines behave polyelectrolyte character.
The average hydrodynamic size and zeta potential of diluted aqueous solutions of
hydrophobic polybetaines containing tetradecyl- and octadecyl groupswere studied as
a function of pH. Anomalous low values of the isoelectric point (IEP) of amphoteric
macromolecules were found to be in the range of pH 2.7–3.4. The TEM results revealed
that in both aqueous KOH and DMSO media the nano- and microsized micelles and
vesicles are existed. The structural organization of micelles and vesicles in water
and water DMSO mixture is discussed. Langmuir-Blodgett (LB) monolayers on the
water-air interface were obtained by spreading of hydrophobic polybetaines
containing tetradecyl- and octadecyl groups dissolved in THF on the subphase
surface. The LB films on the subphase surface are characterized by the specific areas
of 0.6 0.05nm2 monomeric unit
1 at collapsed state. In the spectra of Langmuir-
Blodgett filmthe absorption band with the maximumat 255 and 270nmwas observed.
