Selective Localization of Nanofillers: Effect on Morphology and Crystallization of PLA/PCL Blends

Adding nanofillers to PLA/PCL blends to change their surface and interface properties can improve their phase morphology. Here the selective localization of CNTs and organoclays as the third component in the blend is studied. It is found that clay is selectively localized in the PLA phase and at the phase interface whereas CNTs are mainly found in the PCL phase and at the phase interface. With a reduced viscosity ratio of the blend matrices, the CNTs change their preferred localization from PCL to PLA. The effects of the different selective localization of clay and CNTs on the morphologies are studied. In addition, the crystallization behavior of ternary systems also shows a strong dependence on the selective localization of nanofillers. In biodegradable PLA/PCL immiscible blend systems, clay and carbon nanotubes present different selective localization behaviors. The former is selectively localized in the PLA phase and phase interface, while the latter is mainly dispersed in the PCL phase and phase interface. These two selective localizations can be used as powerful tools to design phase morphology of the matrix blends and to control crystallization of the component polymers.