Effect of compounding procedure on mechanical properties and dispersed phase morphology of poly(lactic acid)/polycaprolactone blends containing peroxide

Side feeding technique was applied to poly (lactic acid) (PLA)/polycaprolactone (PCL) blends containing peroxide. Feeding procedures attempted were blanket and split feeding. In the former procedure, all the materials were fed into the main hopper at once. On the other hand, the feeding of materials was split by using main hopper and side feeder in the later procedure. The results indicated that static tensile properties were not dependent on feeding procedure, but the impact strength was superior in the case of the split feeding samples. It is noteworthy that the impact strength of the split feeding sample was considerably affected as it was four times better. Coarse dispersions such as continuous filament and layer dispersions were formed in the blend specimens without peroxide. On the other hand, fine dispersions were formed in the blend specimens containing peroxide which served as compatibilizer in this blend system. Peroxide addition through the side feeder brought about fine dispersions, promoted adhesion at the interface, and increased viscous nature of the PCL phase. (c) 2006 Wiley Periodicals, Inc.