In recent years, considerable interest has been focused on biodegradable polymers due to their obvious environment friendly property comparing to conventional nondegradable
or slowly degradable synthetic petrochemical-based polymeric materials [1, 2]. Biodegradable polymers degrade in a physiological environment by macromolecular chain
scission into smaller fragments, and ultimately into simple stable end-products [3]. The degradation may occur via different pathway, such as catalysis of aerobic or anaerobic microorganisms, biologically active processes (e.g., enzyme reactions), and hydrolytic cleavage [4]. Poly(lactic acid)(PLA) is the most important plastic derived from renewable resources [5]. PLA-based products (e.g., NatureWork) have been extensively used for their application in biomedical field [6]. However, disadvantages of PLA are inherent brittleness and low toughness despite high tensile modulus and strength