Characterization of microstructure and compressive deformation behavior of reinforced porous poly(L-lactide)

Novel reinforcements such as beam, film, and porous frame were developed to improve the mechanical properties of poly(L-lactide) (PLLA) scaffolds. A solid-liquid phase separation method was used to fabricate porous structures such as core portions and porous frame of reinforced scaffolds. The beam and film reinforcements were also fabricated from PLLA pellets by applying the thermal-press technique. In the standard scaffold, the localized deformation was characterized as buckling of the pore structures. On the contrary, the primary microstructural deformation mechanism in the beam and the film reinforced scaffolds was characterized as buckling deformation and interfacial failure of the matrix and the reinforcement respectively. It is also seen that the inner porous structure could maintain the initial structure without local buckling of the pore structure. The compressive mechanical properties of the reinforced scaffolds were dramatically improved by about 2 - 5 times compared to the standard scaffold.