The effect of clay on the thermal degradation of polyamide 6 in polyamide 6/clay nanocomposites

• Published in: Polymer (Guilford) Vol. 46; no. 10; pp. 3264 - 3274
• Main Authors: Jang, Bok Nam, Wilkie, Charles A.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 25.04.2005; Elsevier
• Subjects: Applied sciences; Clay; Composites; Exact sciences and technology; Forms of application and semi-finished materials; Nanocomposite; Polyamide 6; Polymer industry, paints, wood; Technology of polymers; Polyamide 6; Clay; Nanocomposite; Amide 6 polymer; Organic clay; Montmorillonite; Dispersion degree; Concentration effect; Reaction mechanism; Experimental study; Thermal stability; Thermal degradation
• ISSN: 0032-3861; 1873-2291
• DOI: 10.1016/j.polymer.2005.02.078

The degradation pathway of polyamide 6/clay nanocomposites was studied as a function of clay content. Well-dispersed polymer–clay nanocomposites can be easily obtained by simple melt blending between organically-modified clays and polyamide 6. Polyamide 6–clay nanocomposites exhibit a large reduction in the peak heat release rate, 60%, measured by cone calorimetry. There are no significant differences in the evolved products during thermal degradation of polyamide 6 and polyamide 6/clay nanocomposites in terms of composition and functionality. The main degradation pathway of polyamide 6 is aminolysis and/or acidolysis, primarily through an intra-chain reaction, producing ε-carprolactam, which is the monomer of polyamide 6. As the clay loading is increased, the relative quantity of ε-carprolactam in the evolved products decreases and the viscosity of the soluble solid residues increases. It is thought that inter-chain reactions become significant in the presence of clay because the degrading polymer chains are trapped in the gallery space of the clay during thermal degradation.