utilizing polymeric materials for damping mechanical waves is of great importance in various fields of applications such as military camouflage, prevention of structural vibrational energy transfer, and noise attenuation. this ability originates from segmental dynamics of chain-like polymer molecules. damping properties of styrene-butadiene rubbercontaining 10 wt% of monosize polystyrene partic...

Fe3O4 nanostructures were synthesized via a facile hydrothermal reaction. The effect of various surfactants such as cationic and anionic on the morphology of the product was investigated. Magnetic nanoparticles were added to poly styrene for preparation of magnetic nanocomposite. Nanostructures were then characterized using X-ray diffraction, scanning electron microscopy and Fourier transform i...

w       ater born poly(styrene-butyl acrylate)/clay nanocomposite latexes were synthesized by a novel initiating system of activators generated by   electron transfer (aget) in a system of atom transfer radical polymerization   (atrp). initially, the clay was swelled in a mixture of styrene, butyl acrylate,   and hexadecane. the mixture was then sonicated to obtain a stable miniemulsion. to   s...

A facile synthetic route towards phenylene vinylene systems with methyl substituents at the vinyl linkages is demonstrated through palladium catalyzed Heck coupling of 1,4-diisopropenylbenzene with aryl bromides. The coupling leads to a series of model compounds that feature, in some cases, direct access to a trans-configuration at the double bonds. The oxidative stability of these systems is s...

The title compound, [PdCl(2)(C(8)H(11)O(2)P)(2)], has a comparable structure to those of related palladium dichloride complexes containing trimethyl phosphinite and methyl diphenyl phosphinite. The Pd atom is located on a crystallographic twofold rotation axis: thus, there is just one half-mol-ecule in the asymmetric unit. The structure is isomorphous with the platinum analogue cis-[PtCl(2){P(O...

A detailed investigation into the influence of phosphines, additives, bases and solvents on the Heck coupling reaction of 4-trifluoromethyl-1-chlorobenzene (2) is presented. It is shown that a number of catalyst systems exist for efficient cross coupling of electron-deficient aryl chlorides with various olefins. Basicity and steric demand of the ligand are two factors which determine the succes...

Surface wetting on polyelectrolyte multilayers (PEMs), prepared by alternating deposition of polydiallyldimethylammonium chloride (PDDA) and poly(styrene sulfonate) (PSS), was investigated mainly in water-solid-oil systems. The surface-wetting behavior of as-prepared PEMs was well correlated to the molecular structures of the uncompensated ionic groups on the PEMs as revealed by sum frequency g...

Removal of sulfur and nitrogen compounds from national commercial diesel through adsorption onto activated carbon was studied. Brazilian commercial activated carbon samples (AC) were modified by acid oxidation and, alternatively, were impregnated with palladium chloride. Modified carbon samples showed a significant increase in the quantity of acid sites, particularly those AC submitted to impre...