Processing Degradation of Polyamide 6/Montmorillonite Clay Nanocomposites and Clay Organic Modifier.
Processing Degradation of Polyamide 6/Montmorillonite
Clay Nanocomposites and Clay Organic Modifier.
(983 K)
Davis, R. D.; Gilman, J. W.; Vanderhart, D. L.
Polymer Degradation and Stability, Vol. 79, 111-121,
2003.
Keywords:
polyamides; spectroscopy; degradation; nanocomposites;
clay
Abstract:
Under injection molding conditions, typical of
industrial processing, in situ polymerized
montmorillonite/polyamide 6 nanocomposites significantly
degraded, producing a four-fold increase in -caprolactam
(monomer) content and a significant reduction in number
average molecular mass, as compared to the as-received
nanocomposite. Degradation was believed to occur via
peptide bond scission following attack by water that is
most likely released from the polymer and the
montmorillonite clay surface at the 300 C (12.5 min)
processing conditions. Under identical injection molding
conditions, virgin polyamide 6 number average molecular
mass did not decrease (within experimental uncertainty);
however, a small increase in monomer content was
observed. Characterization methods included solution 13C
nuclear magnetic resonance spectroscopy, infrared
spectroscopy, gel-permeation chromatography, and thermal
gravimetric analysis.
