Miscibility of poly(lactic acid)(PLA) and poly(ethylene oxide) (PEO) was investigated by DSC, FT-IR, and SEM. The PLA/PEO blends had two melting temperatures ; the one due to the PEO phase decreased as the amount of PLA was increased, while the other due to the PLA phase did not change much as PEO was added. The change in the position of the stretching vibration of the carbonyl group was negligible. AB-type diblock and ABA-type triblock copolymers of PEO and PLA were synthesized and were used as compatibilizer for PLA/PEO 60 : 40 blend. As PLA/PEO blends were compatibilized by either diblock or triblock copolymers, the size of the PEO domain of blends was diminished, the tensile strength was increased, and the melting point was depressed. The effect was more pronounced in blends compatibilized by diblock copolymers than those containing triblock copolymers.

Poly(lactic acid) (PLA)와 poly(ethylene oxide) (PEO)블렌드의 상용성을 DSC, FT-IR 및 SEM을 이용하여 조사하였다. 블렌드는 두 개의 용융 피이크를 나타내었으며, PEO상의 용응 온도는 PLA를 첨가함에 따라 감소하였으나, PLA상의 용응 온도는 거의 변화하지 않았고, FT-IR로 관찰한 블렌드의 카르보닐기 피이크의 위치는 블렌드의 조성에 따라 거의 이동하지 않았다. PLA/PEO의 AB형 diblock 및 ABA형 triblock 공중합체를 합성하여 PLA/PEO 블렌드의 상용화제로 사용한 결과, PLA상의 용융 온도가 변화할 뿐만 아니라 PEO domain의 크기와 모양이 변화하고, 인장 강도가 증가하는 거동을 보였으며, 이와 같은 현상은 triblock 공중합체에 비하여 diblock 공중합체에서 더 현저하게 나타났다.

Keywords: poly(lactic acid)(PLA); poly(ethylene oxide)(PEO); PLA/PEO blends; compatibilizer; PLA-PEO block copolymer