Hydrogen peroxide/UV treatment on polylactide/polyurethane blends for biomedical applications

Biodegradable polymers should be non-toxic, possess low immunogenicity and good mechanical properties. Due to their hydrophobicity and their low surface energy cells only poorly attach, spread and proliferate on these biodegradable polyesters. Therefore, the surface of these polyesters should usually be modified and already several approaches have been presented to increase their cell affinity. In this research the influence of hydrogen peroxide combined with ultra violet irradiation on wettability, morphology and mechanical properties of PU/PLA blends as well as their pure components. It was clearly visible that both pure PU and PLA acted completely different form PU/PLA blend during treatment. The wettability of pure polymers changed after H2O2/UV, PU surface became more hydrophilic, whereas PLA becomes slightly hydrophobic. Due to micropores and microcracks visible on surfaces resulted from breaking ester linkage, deterioration of their mechanical properties was also observed. The exposure of PU/PLA films to H2O2/UV irradiation showed the change of wettability toward more hydrophilic and increase of mechanical properties because of specific affinity to the etching process.