A number of methacrylate ionic monomers with different structures and mobilities of ionic centers were synthesized. The free-radical polymerization of these monomers in solution affords high-molecular-mass (M (sD) = 0.5 to 2.5 x 10(6)) thermally stable (T (dec) > 170A degrees C) polyelectrolytes or cationic or anionic "polymeric ionic liquids." The conductivities of polycation- and polyanion-derived coatings are (7.4 x 10(-10))-(7.6 x 10(-7)) and (4.9 x 10(-10))-(1.6 x 10(-7)) S/cm (25A degrees C), respectively. As exemplified by poly(1-[3-(methacryloyloxy)propyl]-3-methylimidazolium bis[(trifluoromethanesulfonyl)imide]), the molecular mass and glasstransition temperature of the polymer affect the ionic conductivity of the film coating. The transition from linear polyelectrolytes to crosslinked systems based on ionic monomers and poly(ethylene glycol dimethacrylate) 750 leads to the formation of elastic films featuring satisfactory strength, reduced glass-transition temperatures (-8 to +15A degrees C), and increased ionic conductivity (up to 3.2 x 10(-6) S/cm (25A degrees C)).