부산대학교 도서관

Among the various kinds of copolymers that can be used as compatibilizers in poly (lactic acid) (PLA) and poly(ε‐caprolactone) (PCL) blends, copolymers containing segments of ε‐caprolactone and ethylene glycol (PEG) are an interesting choice because they are also biodegradable and biocompatible. A multiblock copolymer containing PEG and PCL segments, synthesized via one‐step bulk polycondensation, is added into PLA/PCL blend (80/20 wt%) at 1 and 5 wt% from the molten state, using a twin‐screw extruder. The effect of the PEG‐b‐PCL copolymer on the mechanical properties of PLA/PCL blends is investigated by tensile and Izod impact tests. The mixing of PCL with PLA does not promote adequate matrix toughness due to the incompatibility between the phases. The addition of only 1 wt% of the multiblock copolymer little changes the mechanical behavior of the blend. Only the compatibilized PLA/PCL blend with 5 wt% of the multiblock copolymer exhibits a significant increase in strain at break and notches Izod impact resistance in comparison with uncompatibilized PLA/PCL blends or neat PLA. Therefore, the addition of the PEG‐b‐PCL multiblock copolymer results in a marked change in the mechanical behavior, from brittle to ductile at room temperature, and confirms its compatibilization potential for the PLA/PCL immiscible blends. [ABSTRACT FROM AUTHOR]