Mechanical and Optical Properties of Polyamide 6/Clay Nanocomposite Cast Films: Influence of the Degree of Exfoliation

PA6 nanocomposite films with different nanoclay dispersion degrees are prepared by melt compounding and cast extrusion. The dispersion of the MMT platelets (homogeneity and degree of exfoliation) is evaluated qualitatively by TEM and quantitatively by rheology and NMR; it ranges from microcomposites to highly exfoliated nanocomposites. Compared to neat PA6, the optical properties (clarity, gloss, haze) are worse for the microcomposites and better for the nanocomposites. The mechanical properties depend strongly on the exfoliation level. Better exfoliation leads to higher stiffness. The strain at break decreases compared to neat PA6 films even in the case of highly exfoliated nanocomposites films. At low MMT content, the microcomposite has a higher ductility than well exfoliated nanocomposites films.