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Abstract
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A trifunctional organo alkoxysilane (3-aminopropyl)
triethoxysilane (c-APS) has been used as reagent
for the chemical modification of montmorillonite clay. Silane
grafting was taken place in dry and hydrolyzing conditions.
Silane grafted and pristine clay took part in
interfacial polycondensation process to deposit a layer of
nylon-66 onto the clay lamellae and therefore, enhance
their affinity with nylon-66 matrix. Evidence of presence
of grafted silane molecules and deposition of nylon-66 on
clay particles were provided by Fourier transform-infrared,
thermogravimetric analysis (TGA), and X-ray diffraction
(XRD). Such modified clays and pristine clays were
melt compounded with nylon-66. The structures of the
resulting nylon composites were characterized using XRD
and transmission electron microscopy and the results showed presence of both intercalation and exfoliation.
TGA thermograms of nanocomposites indicated improved
thermal stability upon the incorporation of silane grafted
montmorillonite. Furthermore, differential scanning calorimetry
scans showed that silane modified clays promoted
crystallization in nanocomposites. Increase of storage modulus
and depression of tan d peak in nanocomposites in
dynamical mechanical thermal analysis were observed.
The rheological properties of nylon-66 and nanocomposites
were also evaluated and differences in values of complex
viscosity of samples were noticed.
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