Mechanical properties and porosity of polylactide for biomedical applications

In this study, the strength, ductility, and porosity of polylactide films prepared by immersion precipitation and film casting in air were investigated. To induce extra porosity in the films, dodecane was added to the polymer casting solution. The structure, porosity, and mechanical properties of the films were evaluated. The ultimate strength and elastic modulus of neat poly(L-lactide) prepared by film casting were at least twice those of the same film prepared in methanol, whereas the ductility of these films was considerably higher than that for air. The porosity, size of pores, and interconnectivity of pores increased gradually with increasing dodecane concentration. This dodecane-induced porosity (as high as 80%), progressively reduced the ultimate strength and modulus of practically all films but remarkably improved the ductility of films prepared in air, and this can be related to a decrease in the crystallization temperature. For films prepared in water or poly(D,L-lactide) films in general, the ultimate strength, modulus, and ductility of films prepared in water were significantly lower than those of air-cast poly(L-lactide) films. In summary, the results obtained in this research show that it is possible to tailor the properties of films for various biomedical applications through the use of the polymer type, preparation method, and dodecane-induced porosity as tool