In this work, "in vitro" degradation of poly(beta-hydroxybutyrate) (PHB) / poly(L-lactic acid) (PLLA) blends was evaluated. Films of PHB/PLLA blends, in the compositions 0/100, 30/70, 50/50, 70/30 and 100/0 (% weight), were fabricated by casting. The films obtained were immersed in a phosphate buffer solution, PBS (pH 7.4) for 12 months. The samples were characterized by MDSC, TG, DMA, SEM, WAXS and SAXS, before and after the degradation process. The results showed that the PHB/PLLA blends are immiscible and present phase separation as indicated by microscopy. The PLLA loses mechanical properties faster than PHB, during the degradation process. It was observed that the blends increased their crystallinity degree and long period thickness as a function of degradation time.
Blends; bioreabsorbable polymers; biomaterials; poly(beta-hydroxybutyrate) (PHB); poly(L-lactic acid) (PLLA)
