Desenvolvimento de nanocompósitos poliamida 11 / dióxido de titânio para aplicação na indústria petrolífera
Abstract
The depth at which explores offshore oil grew abruptly, forcing the
advancement of technology in relation to the knowledge acquired so far. For the
risers operating conditions, subject to internal relatively low pressures, but
exposed to high traction levels, the failure of the tensile armor connection due to
disruption of the outer plastic layer has been appointed as the main failure
mode to be investigated. The breakdown of protective layers allows the
passage of corrosive solutions (gas and sea water) into the duct, accelerating
the degradation process by the combination of factors associated with fatigue
and corrosion. As a result, the verification of useful life of these risers is
becoming increasingly important, justifying the development of reliable methods
of inspection and high technologies that increase the estimated life of the
components. In this study, the effects of the surface chemical modification of
titanium dioxide (TiO2) nanoparticles and their addition into polyamide 11
(PA11) on the mechanical, dynamic-mechanical, and tribological properties of
PA11/TiO2 nanocomposites were investigated, aiming the use in the outer
plastic layer of offshore risers. The nanoparticles were incorporated by means
of two different processes: by extrusion and by internal mixer Haake. The
results led to the conclusion that the incorporation of titanium dioxide
nanoparticles (TiO2) in a polyamide 11 (PA11) matrix has promising application
potential in increasing the life cycle of the outer layer, especially with regard to
increased the wear resistance. However, this conclusion is valid only if an
appropriate dispersive and distributive mixing is obtained, since the differences
between modified and non-modified composites are more strongly influenced by
the dispersion of load than by the chemical compatibility between the PA 11
matrix and the modifier.