Chemical modification of hybrid nanostructures (POSS) for application as lubricant

Polyhedral oligomeric silsesquioxanes (POSS) are hybrid structures type RSiO15 n , with n organic groups R. These molecules can be easily functionalized by simply changing the chemical constitution of the organic groups. In this work, chemical modification of POSS-NH 2 was performed by amidation reaction with butyric acid at elevated temperature, 160°C. The formation of the amide group is evinced by the appearance of NH angular deformation band at 1540 cm -1 in the FTIR spectra. Approximately 40% of the amino groups reacted, according to titration results. The formation of the amide groups resulted in a shift of the glass transition temperature ( T g ) from -36.9°C to -25.6°C for the modified-POSS sample. Both POSS-NH 2 and modified-POSS samples exhibited similar thermal degradation pattern. Analysis of the pairs distribution function (PDF) has determined that the hybrid nanoparticles are separated by a periodic distance of approximately 1.32 nm. POSS-NH 2 and modified-POSS exhibit newtonian behavior, which will range from 10 -1 s -1 and 1000 s -1 . The viscosity decreased with increasing temperature, a typical behavior of liquid lubricants. http://dx.doi.org/10.18226/23185279.v2iss1p19