shows the SEM images of PLLA/ABS blends without addition of any compatibilizers. For the PLLA/ABS = 70/30 blend, ABS forms domain dispersed in the PLLA matrix. The ABS domain size ranges from 1 to 10 lm. It is seen that the interface between the two phases is very weak, indicating a totally incompatible polymer blend. For the PLLA/ABS = 50/50 blend, ABS domains tend to connect each other and shape of the phase becomes irregular. The detail observation shows that ABS is still
the domains dispersed in PLLA matrix, which can be attributed to the higher ABS viscosity than PLLA even with the same content of the two components.