RAMOS FILHO, F. G.; http://lattes.cnpq.br/0101527673628570; RAMOS FILHO, Florêncio Gomes de.
Resumen:
In this work, polypropylene nanocomposites (PP) / bentonite were
prepared by the melt intercalation method, employing an extruder
coupled to the Haake torque rheometer. Initially, two
bentonites, a commercial sodium - Brasgei (BRG) and a partially sodium -
Sludge Green (VDL) - were modified with a quaternary ammonium salt aimed at
synthesize organophilic clays. These clays were characterized by
chemistry, infrared spectroscopy (FTIR), X-ray diffraction (XRD) and
thermogravimetry (TG). The results of these analyzes showed that the salt was
incorporated into the clays, thus obtaining organophilic clays. A
study of the best method of incorporating clay into polypropylene. Two
methods were studied. One employing direct extrusion of the cold
PP / bentonite and another using extrusion of a PP / bentonite concentrate in
concentration of 1: 1, which was prepared in an internal mixer (Rheomix 600)
coupled to the Haake torque rheometer. This last method contributed to the
better dispersion of the clay in PP. It was also evaluated the effect of the
processing on the properties of PP / bentonite systems. Two temperatures
were studied (210 ° C and 180 ° C). Systems processed at 210 ° C
presented better mechanical properties. Thus,
PP / bentonite containing BRG (unmodified and modified) sodium bentonite and
VDL polycationic bentonite (unmodified and modified), in contents of 1 to 5%
by weight, were processed at 210 ° C using the
focused. The results obtained showed that the type and content of bentonite
had influence on the mechanical and thermal properties of PP. The best
bentonite-containing systems and
low levels (1-3% by mass). The results also showed that, in a
In general, the modification of bentonites had little influence on
mechanical properties of PP / bentonite systems. On the other hand, thermal stability was
strongly affected. The PP / bentonite systems, containing modified bentonite,
thermal stability considerably higher than
containing unmodified bentonite. The result was attributed to the formation of
nanocomposite as indicated by the XRD data.