writer：Defeng Wu, Yisheng Zhang, Lijuan Yuan, Ming Zhang, Weidong Zhou
keywords：polylactide (PLA); poly( -caprolactone) (PCL); blend; compatibilization; rheology.
source：期刊
Issue time：2010年

Journal of Polymer Science Part B: Polymer Physics, 2010, 48, 756-765.

ABSTRACT:

Polycaprolactone/polylactide blend (PCL/PLA) is an interesting biomaterial because the two component polymers show good complementarity in their physical properties. However, PCL and PLA are incompatible thermodynamically and hence the interfacial properties act as the important roles controlling the final properties of their blends. Thus, in this work, the PCL/PLA blends were prepared by melt mixing using the block copolymers as compatibilizer for the studies of interfacial properties. Several rheological methods and viscoelastic models were employed to establish the relations between improved phase morphologies and interfacial properties. The results show that the interfacial behaviors of the PCL/PLA blends highly depend on the interface-located copolymers. The presence of copolymers reduces the interfacial tension and emulsified the phase interface, leading to stabilization of the interface and retarding both the shape relaxation and the elastic interface relaxation. As a result, besides the relaxation of matrices and the shape relaxation of the dispersed PLA phase, a new relaxation behavior, which is attribute to the relaxation of Marangoni stresses tangential to the interface between dispersed PLA phase and matrix PCL, is observed on the compatibilized blends. In contrast to that of the diblock copolymers, the triblock copolymers show higher emulsifying level. But both can improve the overall interfacial properties and enhance the mechanical strength of the PCL/PLA blends as a result.

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http://www3.interscience.wiley.com/journal/123287185/abstract