INTERFACIAL MODIFICATION IN POLYOLEFIN BLENDS

摘要

Blending of thermoplastic polymers is of great commercial interest since the resultant material combines the properties of the different polymeric phases. The mechanical properties of these multiphasic blends are to a large extent determined by the morphology, i.e., the size, shape and distribution, of the components. One of the key factors for controlling morphology is modifying the adhesion between the phases since the interface represents a weakness across which stress may be poorly transmitted. Graft or block copolymers which locate preferentially at the interface, referred to as compatibilizers, are used to modify the blend morphology. In this work, we have evaluated a new type of interphasic polymer, formed in a two-stage process which results in a segmented compatibilizer with a linear molecular structure for each segment and narrow molecular weight and composition distributions. Improvements in the mechanical properties of blends, as well as changes in the morphology, are presented.