Polymorphism in nylon 6/clay nanocomposites

X-ray diffraction methods and DSC thermal analysis have been used to invest igate the structural change of nylon 6/clay nanocomposites. Nylon 6/clay ha s been prepared by the intercalation of epsilon -caprolactam and then exfol iating the layered synthetic saponite by subsequent polymerization. Both X- ray diffraction data and DSC results indicate the presence of polymorphism in nylon 6 as well as in nylon 6/clay nanocomposites. This polymorphic beha vior is dependent on the cooling rate of nylon 6/clay nanocomposites From t he melt and on the content of synthetic saponite in nylon 6/clay nanocompos ites. The quenching from the melt induces the crystallization into the gamm a crystalline form. The addition of synthetic saponite may increase the cry stallization fate of the alpha crystalline form at lower synthetic saponite content and promote the heterophase nucleation of gamma crystalline form a t higher synthetic saponite content. The effect of thermal annealing on the crystalline structure of nylon 6/clay nanocomposites in the range between T-g and T-m is also discussed.