Comparative studies have been made on the rheological and mechanical properties of polypropylene(PP)/high density polyethylene (HDPE) binary blends or PP/HDPE/ethylene-propylene-diene terpolymer(EPDM) ternary blends and PP/low density polyethylene(LDPE) binary blends or PP/LDPE/EPDM ternary blends. Morphological analysis has been also performed using scanning electron microscopy. Blends have been prepared by melt mixing in an extruder. The rheological measurement and morphology showed that the interfacial adhesion between PP and HDPE was better than between PP and LDPE, even though both the PP/HDPE and PP/LDPE binary blends were typical incompatible systems. The viscosity of binary blends of PP with HDPE or LDPE increased with the addition of EPDM. The impact strength of the PP/PE binary blends were strongly improved by the addition of the EPDM at the expense of slight loss in yield strength and initial elastic modulus. It was found that the toughening effect by EPDM was more prominent in PP/HDPE blends than PP/LDPE blends, due to the better interfacial adhesion between EPDM and HDPE than EDPM and LDPE.

폴리프로필렌(PP)과 고밀도폴리에틸렌(HDPE) 혹은 저밀도폴리에틴렌(LDPE) 이성분계 및 PP/HDPE/EPDM 혹은 PP/LDPE/EPDM 삼성분계 블렌드의 유변학적 및 기계적 물성에 대한 비교연구를 행하였다. 블렌드는 압출기를 이용하여 용융혼합하여 제조하였다. PP/HDPE 및 PP/LDPE 이성분계 블렌드는 전형적인 불상용성을 보였지만 PP와 HDPE간의 계면점착력이 PP와 LDPE간의 그것보다는 양호한 것으로 나타났다. 블렌드의 점도는 EPDM 함량의 증가에 따라 증가하였다. EPDM 함량의 증가에 따라 PP/PE 이성분 블렌드의 항복응력과 탄성율은 약간 감소하였지만 충격강도는 상당히 개선되었다. EPDM에 의한 이러한 강인화 효과는 EPDM이 LDPE보다 HDPE와의 계면점착성이 좋음으로 인해 PP/LDPE 블렌드 보다 PP/HDPE 블렌드의 경우가 더 크게 나타났다.