engleski

Encapsulation phenomenon in PP hybrid composites

The multiphase systems very often take part in the development of new polymeric materials. Such multiphase systems are the hybrid polymer composites, which also contain (beside the basic polymer and filler) an elastomer component. Structure and properties of three-phase polymer composites depend very much on the properties of each component, their miscibility and processing properties, as well as the adhesion between the components. In the ternary polymer composites, three different microstructures can occur: separate microstructure, core-shell microstructure and combination of both (random microstructure). The existing microstructure can strongly affect the performance of the corresponding composites. The purpose of the research work was to study the structure of different polypropylene (PP) hybrid composites and to find out the impact of core-shell microstructure on mechanical properties of the composites. Ternary composites PP/talc/elastomer and PP/wollastonite/elastomer were investigated in our study. Different styrenic block copolymers poly(styrene-b-ethylene-co-butylene-b-styrene) (SEBS) and functionalized SEBS (SEBS grafted with maleic anhydride (SEBS-g-MA)) were used as elastomers. Scanning electron microscopy and optical microscopy were used to determine the structure, while tensile testing and notched impact testing were used to measure mechanical properties. The structure and mechanical properties are presented with emphasis on the interdependence of the core-shell microstructure and mechanical properties. The research showed that the appropriate choice of the components in the ternary composites could lead to the existence of the core-shell microstructure, which, in some cases, can prove to be favorable because of the improved mechanical properties.

polypropylene composites; structure; styrenic block copolymers; talc; wollastonite

nije evidentirano