Influence of sintering temperature on the mechanical properties of ϵ-PCL-impregnated 45S5 bioglass-derived scaffolds fabricated by robocasting

The effect of sintering temperature on the mechanical performance of 45S5 Bioglass® scaffolds fabricated by robocasting and infiltrated by ϵ-polycaprolactone (ϵ-PCL) has been investigated in this work. Infiltration was made by immersion of the robocast scaffolds in a polymer melt to produce fully impregnated, dense co-continuous composites, or in a polymeric solution to produce a polymer-coated bioceramic structure. Polymer infiltration produced a significant increase in the strength and toughness of the scaffolds, both under compression and bending. The strengthening and toughening provided by the polymer was larger in fully impregnated structures than in coated scaffolds, and the toughening was especially dramatic (up to more than two orders of magnitude) under flexural stresses. The strengthening and toughening produced by polymer infiltration increased monotonically with the level of microporosity in the ceramic struts, i.e., they decreased with the sintering temperature. In spite of that, denser ceramic struts yield stronger and tougher hybrid structures after polymer infiltration.