Improving mechanical properties of 13-93 bioactive glass robocast scaffold by poly (lactic acid) and poly (ε-caprolactone) melt infiltration

The effect of polymer infiltration on the mechanical properties of 13-93 bioactive glass scaffolds fabricated by robocasting has been investigated. Biodegradable polymers-poly (lactic acid) (PLA) and poly (ε-caprolactone) (PCL)-were infiltrated into selected robocast scaffolds by immersion of the structure in a polymer melt. The mechanical enhancement achieved upon impregnation on robocast 13-93 structures with fully-dense struts was found to be lower than in the currently existing literature due to the absence of microporosity. The modulus increase is negligible and the strengthening achieved is limited (< 40% in the most favorable case of PLA impregnation under bending). However, the toughening produced by the polymer infiltrate, while lower than previously reported values in microporous structures, is still large (over one order of magnitude); especially when a ductile polymer infiltrate such as PCL is used. Indeed, the 13-93/PCL co-continuous composites were able to survive large strains with significant load-bearing capacity, even under bending stresses, or a rough, manual milling. On the other hand, the dense 13-93 frames fabricated by robocasting acted as good mechanical reinforcements for both polymers, with the exception of PLA under bending stresses.