Crystallization behavior of poly [(butylene succinate)-co-adipate] nanocomposite

The unique crystallization behavior of a poly[ (butylene succinate)-co-adipate] (PBSA) nanocomposite is addressed. Nanocomposites have been prepared by melt blending PBSA and organically modified synthetic fluorine mica (OSFM) in a batch mixer. The structure of the nanocomposite is studied by using X-ray diffraction and transmission electron microscopy, which reveal a coexistence of exfoliated and intercalated silicate layers homogeneously dispersed in the PBSA matrix. The non-isothermal crystallization behavior of PBSA and the nanocomposite samples is studied by differential scanning calorimetry (DSC). Various models, namely the Avrami method, the Ozawa method, and the combined Avrami-Ozawa method, are applied to describe the kinetics of the non-isothermal crystallization. All analyses reveal that the incorporation of the OSFM alters the crystallization properties of PBSA but in ways unexpected from other polymer nanocomposite systems. Polarized optical microscopy is used to support this conclusion. The activation energy for the non-isothermal crystallization of both samples is evaluated by using three different methods. The results show that the absolute value of the activation energy for the nanocomposite is higher than that of the neat polymer. This indicates the slower crystallization kinetics of the nanocomposite. The effect of incorporation of OSFM on the cold crystallization behavior of neat PBSA is also studied by both conventional and temperature-modulated DSC.