Tailoring Mechanical Behavior of PVA-Bioactive Glass Hybrid Foams
Porous scaffolds have been developed in many forms and materials, but few have reached the combination of adequate physical, biological and mechanical properties. In previous works hybrid foams bioactive glass polyvinyl alcohol (PVA) were prepared by the sol-gel process for application as scaffold for bone tissue engineering. We observed that synthesis parameters such as PVA hydrolysis grade, PVA solution concentration, and PVA content in the hybrids affected both synthesis results and structural characteristics of the obtained foams. A marked change in foaming behavior occurs for PVA contents around 60%. In this work we analyze the effect of different compositions and synthesis parameters on the mechanical behavior of PVA-bioative glass foams. The compression tests showed that an increase of PVA fraction changes the mechanical behavior due to different mechanisms leading to cell collapse. For hybrids with lower PVA contents (20 to 30%) the cell collapse is due to brittle crushing. For intermediate polymer content (40-60%) the contribution of plastic yielding in the plateau region increases and it becomes the predominant mechanism of cell collapse for samples with higher polymer content (70-80%).
Guy Daculsi and Pierre Layrolle
H. S. Costa et al., "Tailoring Mechanical Behavior of PVA-Bioactive Glass Hybrid Foams", Key Engineering Materials, Vols. 361-363, pp. 289-292, 2008