Desenvolvimento de nanocompósitos de blendas PA6/ABS compatibilizadas com copolímeros funcionalizados
Abstract
Nanocomposites based on polyamide 6 (PA6) and acrylonitrile-butadienestyrene
(ABS) blends compatibilized with styrene-maleic anhydride-acrylonitrile
(SANMA) and methyl methacrylate-maleic anhydride (MA-MMA) were prepared
by melt blending in a twin screw extruder through different mixing protocols. The
nanoclay incorporation effect, different compatibilizing systems and components
mixing sequence were evaluated in morphological, mechanical, thermal, thermomechanical
and rheological properties. Evidences of chemical interactions
between PA6 and reactive copolymers were observed by torque rheometry. XRD
analysis indicates an exfoliated structure for all the nanocomposites due to the
good interaction between PA6/OMMT. The significant increase in
nanocomposites viscosity when compared with their respective ternary blends
corroborates the results obtained by XRD. TEM micrographs show a strong
influence of both reactive copolymers on polymer blends morphology, where the
presence of SANMA and MMA-MA is responsible for reducing the dispersed
phase particle size when compared to the uncompatibilized blend. TEM images
confirm the existence of an exfoliation structure in all nanocomposites. The
addition of both reactive copolymers significantly increased the ternary blends
toughness when compared with PA6/ABS. Furthermore, the nanoclay
incorporation enhanced the elasticity modulus and HDT of the nanocomposites
but also reduced the toughness and the elongation at break when compared with
their respective compatibilized blends.