Tensile properties and morphology of PP/EPDM/glass bead ternary composites

Abstract

AbstractThe tensile properties of three types of injection molded glass bead (GB) filled polypropylene (PP)/ethylene‐propylene‐diene monomer (EPDM) ternary composites have been determined at room temperature by using an Instron materials testing machine. The effects of the filler surface treatment, the glass bead (GBI) pretreated with a silane coupling agent and the EPDM (EPDM‐MA) modified with a maleic anhydride, and the filler content on the tensile mechanical properties of the ternary PP composites have been investigated. The Young's modulus (Ec) increases while the yield stress (σyc) and tensile fracture strength (σbc) of the composites decrease with increasing the volume fraction of glass beads (ϕg) when the volume fraction of EPDM is constant (ϕe = 10%). The (Ec) values of PP/EPDM/GBI and ϵbc for PP/EPDM‐MA/GB2 (no surface pretreated) systems are the highest at the same ϕg. The tensile fracture energy (Ebc) and tensile fracture strain (ϵbc) of PP/EPDM/GBI and PP/EPDM/GB2 systems appear to peak at ϕg = 25%. However, the Ebc and ϵbc of PP/EPDM‐MA/GB2 system show little changes with increasing ϕg. The fracture surfaces of ternary composites have been examined in a scanning electron microscope. The correlation between the tensile properties and morphologies of these materials have been discussed.