|
Descripción
|
|
|---|---|
| The scaled up high-temperature synthesis of a pure phase of multiwall inorganic nanotubes (INT) and inorganic fullerene-like (IF) nanoparticles of WS2 was recently reported. The majority of the nanotubes range from 1 to 20micron in length and 30 to 120nm in diameter, while the diameter of the IF nanoparticles varies from 50 to 150nm. The nanotubes were shown to exhibit very favorable mechanical properties, i.e. strength of up to 20GPa and maximum strain of about 10%, offering the possibility to use them for reinforcing polymer nanocomposites. Special efforts were committed to produce loosely agglomerated nanoparticles that can be easily dispersed in organic solvents and different polymer matrices. In particular, nanocomposites with IF and INT based on engineering polymers like PEEK, PMMA and epoxy were studied. Tiny amounts of INT/IF (0.5-2.5%) were used to strengthen these polymers. The mechanical and thermal properties of the polymers were significantly improved by using these closed-cage nanoparticles. For instance, PEEK/IF-WS2 composite obtained at different concentartions demonstrated 31% improvement of the storage modulus, 17°C increase of Tg and 60°C increase in the thermal stability of the composite[1]. In another study IF-WS2 were used for obtaining self-lubricating surface of PEEK coatings[2]. It was shown that the addition of 2.5wt% of IF-WS2 reduce the surface coefficent of friction (CoF) of this composite by up to 70%. Electrospun fibers of PMMA composite compounded with INT-WS2 were recently prepared and studied. Their elastic modulus increased 10-20 fold by adding 1-2wt% of INT and this without compromising their tensile strength. Epoxy composite impregnated with 0.5wt% IF-WS2 nanoprticles exhibited enhanced shear strengths and shear moduli together with a significant increase in the peel strengths (up to 100%). The formation of a chemical interaction between the nanoparticles and the epoxy resin was confirmed by FTIR explaining the good adhesion between the IF-WS2 nanoparticles and the polymer matrix. Recently, the tribological properties of epoxy composites with nanoparticles of different geometries like microscopic platelets (2H), quasi-spherical IF and nanotubes were studied. Mainly, all the investigated nanocomposites demonstrated a reduction of the CoF and wear compared to the neat epoxy. However, the improvement was not uniform and varied according to the particles? shape, concentration and experimental conditions. The lowest value of the wear was obtained for INT/epoxy composite, while the lowest coefficient of friction - for IF/epoxy composite. Composites with 2H consistently showed the worst results with respect to both the CoF and wear. Low friction and wear of IF/INT - nanocomposites is associated with the lubricating properties of the INP and their capability to reinforce the polymers matrix. [1] M.Naffakh et al., J. Phys. Chem. B 2010, 114, 11444 [2] X. Hou et al., Surf. Coat. Tech. 2008, 202, 2287 | |
|
Internacional
|
Si |
|
Nombre congreso
|
(MATERIALS RESEARCH SOCIETY) Fall Meeting & Exhibit |
|
Tipo de participación
|
960 |
|
Lugar del congreso
|
Boston, Massachusetts (USA) |
|
Revisores
|
Si |
|
ISBN o ISSN
|
|
|
DOI
|
http://www.mrs.org/fall2013/ |
|
Fecha inicio congreso
|
01/12/2013 |
|
Fecha fin congreso
|
06/12/2013 |
|
Desde la página
|
|
|
Hasta la página
|
|
|
Título de las actas
|
|