Polymerization of the 12‐methacryloyloxydodecanoic acid and a corresponding phospholipid in monolayers at the liquid/gas interfaces

Abstract

AbstractThe following surface‐active monomers with methacrylic group at the end of hydrophobic tail: 12‐methacryloyloxydodecanoic acid (12‐MAODA) and 12‐(methacryloyloxydodecanoyl)‐glycerophosphatidylcholine 12‐MAODPC) were synthesized and investigated. Both monomers are forming monolayers at the liquid/gas interfaces with liquid‐expanded and liquid‐condensed states at low and high surface pressures, respectively. These monomers have been polymerized in the monolayers just by soft UV‐irradiation (254 nm). Dependences of polymerization rate vs. surface pressure for both monomers have maxima (3.33*10−4 s−1 for 12‐MAODPC and 4.89*10−4 s−1 for 12‐MAODA) at about 8–10 mN/m. The higher polymerization rate of 12‐MAODA polymerization as compared to 12‐MAODPC is due to the more dense packing of the acid molecules in monolayers as compared to the lipid. Areas per monomer unit in the obtained polymeric monolayers are much smaller than those for the monomer one. The collapse pressures increase after monomer polymerization that evidences the increase of the monolayer stability in case of polymer as compared to monomer.