Structural engineering of polyurethane coatings for high performance applications

Recently, polymer nanocomposites reinforced with lower volume fraction of nanoceramics and carbon nanotubes have attracted steadily growing interest due to their peculiar and fascinating properties as well as their unique applications in commercial sectors. The incorporation of nanoceramics such as layered silicate clays, calcium carbonate or silica nanoparticles arranged on the nanometer scale with a high aspect ratio and/or an extremely large surface area into polymers improves their mechanical performances significantly. The properties of nanocomposites depend greatly on the chemistry of polymer matrices, nature of nanofillers, and the way in which they are prepared. The uniform dispersion of nanofillers in the polymer matrices is a general prerequisite for achieving desired mechanical and physical characteristics. In this review article, current development on the processing, structure, and mechanical properties of polymer nanocomposites reinforced with respective layered silicates, ceramic nanoparticles and carbon nanotubes will be addressed. Particular attention is paid on the structure–property relationship of such novel high-performance polymer nanocomposites.

Structural and mechanical properties of polymer nanocomposites

Artificial Molecular Rotors

Bipyridine: the most widely used ligand. A review of molecules comprising at least two 2,2'-bipyridine units.

Organoclays: Properties, preparation and applications

Synthese de composes crown azote, de diaza [3.3] meta- et paracyclophanes, de pyridinophanes

Reaction of tosylamide monosodium salt with bis(halomethyl) compounds: an easy entry to symmetrical N-tosyl aza macrocycles

Polystyrene/montmorillonite nanocomposites were prepared via in situ bulk polymerization. New imidazolium salts were used to modify montmorillonite obtaining an improvement in thermal stability in comparison with a montmorillonite modified with a standard alkylammonium cation. The synthesized cations facilitate the formation of partially exfoliated structures because of the presence in their structure of a polymerizable group. The polystyrene/ montmorillonite nanocomposites were characterized by X-ray diffraction, thermogravimetric analysis, scanning electron microscopy (SEM), and transmission electron microscopy (TEM).

Polystyrene-Clay Nanocomposites Prepared with Polymerizable Imidazolium Surfactants

La reaction de calix[4] arenes avec le chlorhydrate de chloromethyl-2 pyridine donne des tetrakis-[pyridyl-2 methoxy] calix[4] arenes

Calix[4]arenes with pyridine pendant groups. Regioselective proximal alkylation at the "lower rim"

Chemical modifications, mechanical properties and surface photo-oxidation of films of polystyrene (PS)

Seven variously substituted derivatives of polyhedral oligomeric silsesquioxanes (POSSs) with general formula R7R′1 (SiO1.5)8, where R- and R′- were a cyclopentyl and a substituted phenyl group, respectively, were prepared in this study, and their compositions were checked by elemental analysis, 1H NMR and 13C NMR spectroscopy. The compounds obtained were studied by TG and DTA techniques, in both flowing nitrogen and static air atmospheres, to draw useful information about their resistance to thermal degradation. Experiments, performed in the 35–700 °C temperature range, showed different behaviours between the two used atmospheres. The formation of volatile compounds only, with a near-complete mass loss, was observed under nitrogen; by contrast, in oxidative environment, a solid residue (≈50% in every case) was obtained because of the formation of SiO2 as indicated by the FTIR spectra performed. The results obtained for the various compounds investigated were discussed and compared with each other, and heat resistance classifications in the studied environments were made.

Francesco A. Bottino

Papers

Reaction of tosylamide monosodium salt with bis(halomethyl) compounds: an easy entry to symmetrical N-tosyl aza macrocycles

Polystyrene-Clay Nanocomposites Prepared with Polymerizable Imidazolium Surfactants

Calix[4]arenes with pyridine pendant groups. Regioselective proximal alkylation at the "lower rim"

Chemical modifications, mechanical properties and surface photo-oxidation of films of polystyrene (PS)

Thermal degradation of differently substituted Cyclopentyl Polyhedral Oligomeric Silsesquioxane (CP-POSS) nanoparticles