Investigation on Strain Rate Sensitivity of 3D Printed sPEEK-HAP/rGO Composites

Abstract Nanofillers can be added to polymers to improve their mechanical behavior. However, the yield behaviour of most polymer composites is influenced by strain rate. The majority of the research focused on the behaviour of polymer composites at high strain rates. This work aims to investigate how hydroxyapatite (HAP) and reduced Graphene Oxide (rGO) nanofillers affect the mechanical properties of sulphonated polyetheretherketone (sPEEK) at low (tensile and compression behaviour) and high strain rates (compression behaviour). The thermal, mechanical, and energy absorption responses of sPEEK filled with HAP and varying mass fraction (Mf) of rGO (0.5%, 1%, and 1.5%) at different strain are studied in detail. The strong strain rate effect was seen in HAp and rGO loaded sPEEK composites. The strain rate sensitivity factor of sPEEK-HAP/rGO improved as the strain rate increased, but decreased when the Mf of rGO increased. Under low strain rate compression, HAp and rGO loaded sPEEK absorbed more energy at Mf about 4%. SEM micrography was used to study the microstructures of the fractured interfaces of the components, revealing that the HAp and sPEEK materials formed a good compatibility in presence of rGO.