Manipulating the Morphology of Poly(ethylene terephthlate) Blends by Capillary Rheometry

摘要

The versatile nature of polymer blends has made them an object of research for many years. One of the application fields of polymer blends is food packaging where poly(ethylene terephthalate) (PET) blends with improved barrier properties have been of great importance. Poly(m-xylene adipamide) (MXD6) or poly(ethylene-co-vinyl alcohol) (EVOH) have been used as the supporting polymers in high gas barrier applications. In polymer blending systems, morphology control which is closely related to the rheological properties of the blend components is of prime importance since the final properties including barrier properties of polymer blends will depend, to a large extent, on the morphology of the dispersed phase, such as its size and shape [1]. In most studies [2-7, 8-16], blends prepared with different blend ratios have been deformed by using a rotational rheometer without damaging the microstructure and the resulting morphological changes have been correlated with the rheological properties of the blend components and the flow conditions. The purpose of this study is to reveal the possible co-continuous phase structure created by the minor component during real processing conditions. Capillary rheometer was chosen intentionally since rheological data obtained with its usage simulate the real processing conditions. In this regard, this study is the first work on the generation of a co-continuous microstructure by using the rheological data delivered by capillary rheometer for PET blends.