Reinforcement and environmental degradation of nylon-6/clay nanocomposites

Hybrid organic/inorganic nanocomposites are being developed to improve the physical and mechanical properties of polymeric materials without adversely effecting their processing characteristics. One such nanocomposite develop ed by Toyota and commercialized by Ube Industries is the nylon-6/montmorill onite clay nanocomposite. The mechanism of reinforcement in nylon-6/clay na nocomposite materials is investigated through tensile experiments, infrared absorption spectrography, and dynamic mechanical analysis. 200% improvemen ts in modulus and 175% improvements in yield stress are attributed to the c omplexation of mid-chain carbonyl groups with the exfoliated clay lamellae. Because of the initial use of these materials in automotive components, an d the known deleterious effects of the air pollutant NOx on nylon-6, the de gradation of the nanocomposites in NOx was examined through post-exposure t ensile experiments. It was found that NOx degrades the mechanical performan ce of the nanocomposites regardless of the constraining effect of clay lame llae. (C) 2001 Elsevier Science Ltd. All rights reserved.