Material extrusion additive manufacturing of bioactive glass/high density polyethylene composites

Abstract

Bioactive glasses (BAG) are renowned for their unique ability to bond with tissues and therefore are used extensively for bone repair and functional recovery. In this work, high density polyethylene (HDPE) reinforced with BAG is processed using material extrusion additive manufacturing (MEAM) for potential orthopaedic applications. The constituents are melt compounded by varying BAG proportions (5, 10, and 20 wt %) and subsequently extruded into filaments. DSC curves show an insignificant change in the peak melting temperature, increase in crystallization temperature, and a decrease in the crystallinity of HDPE with BAG addition. Warpage analysis confirms that the enhanced temperature parameters and BAG addition result in reduced warpage and improved dimensional stability. Rheological results show that the addition of BAG increases complex viscosity, storage and loss modulus. Melt behavior and print parameters are tailored to improve first layer adhesion and interfacial bonding rendering dimensionally stable prints without any print induced defects. Dynamic mechanical analysis (DMA) of printed samples show an increase in storage (E′), loss (E″) modulus, and a decrease in damping factor (Tan δ) with BAG addition. MEAM of the developed H/BAG composites shows a strong potential for developing customizable scaffolds and implants as bone replacements.