OLIVEIRA, S. V.; http://lattes.cnpq.br/2988178262762974; OLIVEIRA, Sara Verusca de.
Resumo:
HOPE nanocomposites were prepared by melt intercalation, in order to
examine the fiame retardant effect of this material For the development of
nanocomposites were used the clay montmoriilonite (MMT), organoclay
(OMMT) and flame retardant (RCP) with the percentage of 1, 3, 6 and 9 wt%.
Grafted polyethylene with maleic anhydride (PE-g-MA) was used as a
compattbilizer of the systems. HOPE and its systems were evaluated: XRD,
TEM, SEM, mechanical properties (tensile and impact), HDT, DSC, TG and
fiammability (UL94HB, oxygen index (LOI) and cone calorimetry). The X-ray
diffraction showed an apparent partial intercalation and exfoliation as well as
formation of rnicrocomposite. The phase morphology of the systems obtained
from the SEM showed dispersion and distribution of clay and flame retardancy.
By TEM it was observed that the system with 1% OMMT clay showed a
predominance of exfoliation. Already the system with 3% OMMT showed partial
exfoliation and exfoliation is reducing as the clay content increased. Comparing
the mechanical properties of the HDPE to systems it was found that the elastic
modulus practically was not changed. By TG it was seen that MMT, OMMT and
RCP acted improving the thermal behavior of the nanocomposites compared to
HDPE matrix. By DSC it was observed that the presence of clay altered the
crystallinity of the matrix. The results obtained for the oxygen index revealed
that both HDPE and their systems presented flame retardant properties. By
means of the horizontal fiammability tests, it was found that the presence of 1 %
MMT clay reduced 25% the fiammability of HDPE. By cone calorimetry was
found that the system contains 9% of OMMT clay decreased by 33% the
fiammability of nanocomposites.