AGRAWAL, P.; http://lattes.cnpq.br/0196840493849504; AGRAWAL, Pankaj.
Resumo:
The aim of this work is to develop polymer/clay nanocomposites from
polymer blends with polyamide 6 (PA6) matrix. First, the effect of polyethylene
grafted with acrylic acid (PEgAA) and polyethylene grafted with maleic
anhydride (PEgMA) functionalized polymers and Ethylene-Methyl Acrylate -
Glycidyl Methacrylate (EG) terpolymer on PA6 and PA6/Cloisite 20A (CL20A)
system. It was observed that PA6 presented higher reactivity with PA6.
However, in the presence of the clay, EG terpolymer showed better result and
was chosen to be used in the development of the nanocomposites. The blends
and the nanocomposites were characterized by X-Ray diffraction (XRD),
Thermogravimetry (TG), Dtfferential scanning calorimetry (DSC), Heat distortion
temperature (HDT), Oscillatory rheometry, Mechanical properties and Scanning
electron microscopy (SEM). XRD tests results indicated that the PA6/EG/CL20A
and PA6/EG/PEAD/CL20A systems presented a partially exfoliated structure.
TG tests showed that the PA6/CL20A and PA6/EG/CL20A systems were the CL
20A clay was premixed with PA6, showed higher thermal stability than that of
PA6 and other systems. DSC results revealed the presence of a melting peak at
~ 212 • C, in the binary and ternary systems were the clay was pre-mixed with
PA6, which was attributed to the y phase of PA6. The results of tensile and
impact tests showed that only the PA6/EG/CL20A ternary and
PA6/EG/PEAD/CL20A quaternary systems where the CL20A clay was premixed
with PA6, presented balanced mechanical properties when compared to
PA6. For the systems containing clay, it was observed by SEM that the clay
was well dispersed in either PA6 or in the blends without the presence of clay agglomerates. The results of XRD, DSC and HDT indicated that for systems
where the clay was premixed with PA6, the clay is preferably located in the PA6
phase. As for systems where the clay was premixed with the EG, the clay is
preferably located in the EG phase.
