The intercalation of organic anions, namely acrylate, methacrylate, 2-acrylamido-2-me thyl-1-propanesulfonate (AMPS), 4-vinylbenzoate, and 4,4’-azobis(4-cyanopentanoate) into Mg-Al and Zn-Al layered double hydroxides (LDHs) was studied. The coprecipitated Mg-Al-NO 3 and Zn-Al-NO 3 hydrotalcite-like compounds with M II /Al molar ratio of 2 were used as precursors. The anion exchange and rehydration of calcined LDH precursors were applied for the intercalation. The anion exchange appeared to be the most effective method; all examined organicanions were intercalated successfully by this way both in Mg-Al and Zn-Al host structur es. The intercalated LDHs were us ed as comonomer and initiator for preparation o f LDH/polymethacrylate nanocomposites: mixture of monomer and LDHs intercalated with organic anions were dispersed in aqueous phase and then the emulsion polym erization was performed in the presence of inorganic (nano)particles to obtain polybutylmethacrylate hybrid latexes. Na nostructured hybrid materials containing a low amount (1 - 3 wt%) of inorganic nanofiller were prepared. Particles with size of 60 - 100 nm were detected by dynamic light scattering and small-angle X-ray scattering methods. Furthermore, a hydrophobization of LDH nanof illers with dodecylsulfate (DS) was tested in order to facilitate their dispersion in the polymer matrix. A minor part of AMPS anions was incorporated into Mg-Al-DS LDH during anion exchange in the aqueous solution containing AMPS. Us ing Mg-Al-DS LDH modified w ith AMPS, the nanocomposites were obtained by emulsion polymerization and also by the solution polymer ization in 1-methyl-2-pyrolidone., František Kovanda, Eva Jindová, Barbora Doušová, David Koloušek, Josef Pleštil and Zdeňka Sedláková., and Obsahuje bibliografické odkazy
Films of aliphatic polyurethane-silica nanocomposite containing up to 27.3 mol. % of silica were obtained by the parallel synthesis of both composite components in one common process. This method permits to obtain the nanocomposite materials with the uniform distribution of nanoparticles in the polymer matrix volume. The rise of the silica concentration in the nanocomposite film was shown to lead from one hand to the progressive fall of both the Young’s modulus and yield stress and from another hand to the rise of the ultimate deformation and thermal expansion coefficient values. These effects were ascribed to the formation of the excessive free volume in the material along with the raise of silica concentration., Josif V. Gofman and Ivan V. Abalov., and Obsahuje bibliografii