MENEZES, P. C. F.; http://lattes.cnpq.br/4419234205228712; MENEZES, Patrícia Costa Fernandes de.
Résumé:
The load of nickel ferrite (NiFe204 ) had its particle size changed by firing,
for incorporation into the matrix of polyamide 6 with two mixing equipment.
Aiming to evaluate the effect of calcination temperature on particle size and
shape of the load of nickel ferrite (NiFe204 ) and its incorporation into the
polymer matrix of nylon 6, but also investigate the influence of changes in
processing conditions between load and matrix. The loading of nickel ferrite
(NiFe204) was used as synthesized by combustion reaction and after
calcination temperatures, 700, 900 and 1200oC and characterized by XRD - X,
X-ray fluorescence, infrared spectroscopy, adsorption nitrogen, scanning
electron microscopy, thermogravimetry and measuring the magnetic
characteristics. To form the composite, the load was incorporated at a
concentration of 50% by weight in a polyamide 6 matrix previously dried in an
oven at 240 0 C/48h by vacuum. The mixture was held at two facilities: a type of
internal mixer coupled to a torque rheometer and a homogenizes The resulting
mixture was characterized by X-ray diffraction, thermogravimetry, scanning
electron microscopy, and testing of selective absorption rate. The results show
that the load as synthesized phase consists of the inverse spinel nickel ferrite,
with traces of hematite (Fe203), and morphology consisting of irregular
clusters. The increase of calcination temperature led to the growth of clusters
and formation of single phase spinel ferrite nickel reverse. The X-ray diffraction
patterns of the composites showed that the increase in the calcination
temperature increased the crystallinity of the cargo, not being altered by
processing, and TG curves of the increase of calcination temperature increased
the thermal stability of the array. For a larger particle size using the
homogenizer promotes good dispersion, no change in particle size. The
selective absorption test showed that the composite produced with the load
synthesized, presented for the frequency attenuation DCS1800, which is used
in cellular telephony.