Retraction Note to: Investigation on the improvement of physico-mechanical, viscoelastic and morphological properties of isotactic polypropylene (iPP)/ethylene-propylene diene rubber (EPDM)/nitrile rubber (NBR) elastomeric blends

Abstract

An attempt has been made to study the mechanical, viscoelastic and morphological behavior of various dynamically cross-linked blends of isotactic polypropylene (iPP) with ethylene-propylene diene rubber (EPDM) and nitrile rubber (NBR) were examined and compared with these of uncross-linked blends of iPP/EPDM/NBR. These blends were prepared by melt blending in an internal mixer at 190 °C in the composition range of 10–40 wt. % EPDM/NBR elastomeric content. The variation in the strength of fibrils of the craze, yield stress and the number density of the EPDM/NBR elastomeric domains (morphology) which are important factors for enhancing the interfacial adhesion and toughness in dynamically cross-linked blends were determined. The toughness and ductility of these blends were discussed with main emphasis on the composition between crack formation and the degree of plastic deformation through crazing and shear yielding. The physico-mechanical properties such as hardness, impact strength, flexural strength and flexural modulus of dynamically cross-linked blends were found to be consistent and displayed enhanced mechanical properties values as compared with uncross-linked blends. The decreases in crystallinity and nucleation effect in cross-linked blends of iPP/EPDM/NBR were considered to contribute in the improvement in the impact strength behavior of the blends prepared.