Preparation and characterization of Bioglass~R-based scaffolds reinforced by poly-vinyl alcohol/microfibrillated cellulose composite coating

摘要

The present work deals with the preparation and mechanical characterization of Bioglass~R-based porous scaffolds reinforced by a composite coating constituted by polyvinyl alcohol (PVA) and microfibrillated cellulose (MFC). Samples were produced by foam replication process, using a novel ethanol-based Bioglass~R slurry. The addition of PVA/MFC coating led to a 10 fold increase of compressive strength and a 20 fold increase of tensile strength in comparison with non-coated scaffolds. SEM observations of broken struts surfaces proved the reinforcing and toughening effect of the composite coating which were ascribed to crack bridging and fracture of cellulose fibrils. The mechanical properties of the coatings were investigated by tensile testing of PVA/MFC composite stripes. The stirring time of the PVA/MFC solution came out as a crucial parameter in order to achieve a more homogeneous dispersion of the fibers and therefore enhanced strength and stiffness.