This research shows the fungal degradation behavior of two series of composites: a series obtained with silver powder incorporated in sulfadiazine (SD)-based polyurethane urea and another series of composites that incorporates silver through polyurethane chain extension with silver SD. This article reports on the chemical structure variations characterized by Fourier transform infrared (FTIR) spectroscopy and the mechanical properties of these polymers before and after fungal exposure. Although silver SD—used as a chain-extender—ensures a more orderly dispersion of the silver throughout the hard segment of the polyurethane urea main chain, the FTIR results showed some changes on the surface of these composite films. Both silver composites exhibited higher fungal biodegradation resistance.