The Selective Localization of Nanofiller and Its Effect on the Morphology and Crystallization of Polylactide/Poly( -caprolactone) Blend.
writer：Defeng Wu, Dongpo Lin, Jie Zhang, Yisheng Zhang, Dongmei Wang, Ming Zhang.
keywords：polylactide; poly( -caprolactone); blend; clay; carbon nanotubes; crystallization.
source：期刊
specific source：Macromolecular Chemistry & Physics, 202(6), 613-626
Issue time：2011年
Macromolecular Chemistry & Physics, 202(6), 613-626
ABSTRACT:
Polylactide/poly( -caprolactone) blend (PLA/PCL) is an interesting biomaterial because of good property complementarity between PLA and PCL. The incompatibility between these two polymers, however, highly restricts their property combinations. Adding the nanofiller to change the surface and interface properties of the PLA/PCL blend is found as a new way to improve its phase morphology. In this case, the selective localization of nanofiller is very important to the morphological design and control. In this work, therefore, two types of nanofiller, carbon nanotubes (CNTs) and organoclay were used as the third component to be compounded with the PLA/PCL blend by melt mixing for the selective localization study. It is interesting that these two types of nanofiller present different selective localization behaviors in the ternary systems: clay is selectively localized in the PLA phase and phase interface, which agrees well with thermodynamical prediction; while CNTs mainly dispersed in the PCL phase and phase interface, contrary to thermodynamical estimation. But with reduced viscosity ratio of the blend matrices, the CNTs change their localization from PCL to PLA phase. The effects of the different selective localization behaviors of clay and CNTs on the morphologies were then further studied. Compared with those of the blank blend, the phase morphologies of the ternary systems are improved remarkably although these improvements follow different mechanisms with different selective localizations. Besides, the crystallization behaviors of ternary systems also show high dependence on the selective localizations of nanofiller: for the melt crystallization of PCL component, only in the case of PCL phase localization can the nanofiller have strong nucleating effect; while for the cold crystallization of PLA component, not only the PLA phase localized clay tactoids, the phase interface localized CNTs can also promote crystallization of the PLA.
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http://onlinelibrary.wiley.com/doi/10.1002/macp.201000579/abstract