Investigation of the Rigid Amorphous Phase of Nylon 6/Montmorillonite Nanocomposites by Temperature-Modulated DSC

摘要

Glass transition, crystalline melting and exothermic transformations ofrnlaponite/montmorillonite-based nylon 6 nanocomposites were investigated byrntemperature-modulated differential scanning calorimeter (TMDSC). The disappearancernof the upper-Tg exotherm and the suppression of the heat capacity change (△DC_p) at thernglass transition suggested the formation of a rigid amorphous phase. The glass transitionrntemperatures of laponite and montmorillonite nanocomposites were examined. Therndramatic shift of the Tg in laponite nanocomposite is attributed to high level of particlerndispersion and low surface polarity of the laponite. The absence of any Tg shift inrnmontmorillonite nanocomposites, in contrast, is suggested to be a consequence ofrnincomplete platelet dispersion that create a montmorillonite-free amorphous phase. Inrncontrast to previous reports on the doublet melting peak of nylon 6 and nylon 6/clayrnnanocomposites, the occurrence of a single crystalline melting and simultaneous crystalrnreorganization was observed.