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Processing Degradation of Polyamide 6/Montmorillonite Clay Nanocomposites and Clay Organic Modifier.


pdf icon 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.