Morphology and Mechanical Properties of Polyketone/Polycarbonate Blends Compatibilized with SEBS and Polyamide

Abstract

To enhance the impact strength of polyketone (PK) without the decrease in its stiffness, PK was blended with polycarbonate (PC). For the effective toughening of PK/PC blends, polyamide 6 (PA6) and mixtures of unmodified poly[styrene-b-(ethylene-co-butylene)-b-styrene] (unSEBS) and maleic anhydride (MA)-grafted SEBS (SEBS-g-MA) were added to the blends as compatibilizers. Examining the fracture surface, it was observed that, by varying the SEBS-g-MA/unSEBS ratio in the compatibilizer, the phase morphology and interphase structure were changed. While PK/PC/SEBS-g-MA/PA6 blend had completely encapsulated PC domains, PK/PC/(SEBS-g-MA/unSEBS)/PA6 blends showed a morphology in which the PC was incompletely encapsulated by SEBS. Morphological differences, such as complete or incomplete PC encapsulation, led to differences in the impact strength. The impact strength of the blends with incomplete encapsulation of PC was higher than that with complete encapsulation of PC. Through the investigation of fracture behaviors, it was confirmed that the impact strength of PK/PC/(SEBS-g-MA/unSEBS)/PA6 was enhanced due to debonding around the incompletely encapsulated PC particles and matrix shear yielding.