The influence of reactive compatibilization on uniaxial large strain deformation and fracture behavior of polyamide 6 and poly (ethylene- co-butyl acrylate) blends

Abstract

The role of reactive compatibilization on the uniaxial tensile deformation and fracture resistance behavior of polyamide 6 (PA6) and ethylene- co-butyl acrylate (EBA) was systematically studied by using the maleated derivative of EBA containing two different MAH graft percentages of 0.49 (EBA-g-MAH 0.49) and 0.96 (EBA-g-MAH 0.96) as reactive compatibilizers. In the uncompatibilized PA6/EBA blends, debonding at the polymer/elastomer interface was observed during tensile deformation. At lower EBA concentrations, the interface cavitation resistance is relatively good with higher work of yield in these samples. This interface cavitation has generated extensive matrix shear yielding in the samples during cold drawing after localized necking. At higher EBA concentrations, cavitation resistance was relatively poor, leading to macro-voiding around the elastomer domains, and the stress–strain behavior of the samples showed rubber like deformation. In the compatibilized blends, the high interfacial adhesion achieved by reactive compatibilization prevented interface cavitation and arrested cold drawing of the samples at higher compatibilizer concentration. The essential work of fracture (EWF) method revealed that the compatibilized PA6/EBA blends show much better fracture resistance than the uncompatibilized blends. High interfacial adhesion with finer dispersion of EBA domains induced extensive shear yielding with the formation of thin ligaments during EWF testing in compatibilized blends, which is assigned to be responsible for the higher crack resistance behavior of these blends.