The miscibility and biodegradability of poly(3-hydroxybutyrate) blends with poly(butylene succinate-co-butylene adipate) and poly(butylene succinate-co-epsilon-caprolactone)

The solid-phase structure and biodegradability were investigated for a seri es of binary blends of bacterial poly(3-hydroxybutylate) with chemosyntheti c poly(butylene succinate-co-butylene adipate) (PBSA) and poly(butylene suc cinate-co-epsilon-caprolactone) (PBSC) prepared via compression molding of solution cast films. By high-resolution solid-state C-13 NMR and wide-angle X-ray diffractometer, the solid-state structures of both binary blend syst ems were studied. It was clearly demonstrated that these blends were immisc ible systems on an observation scale of TP (several tens of nm) over the wh ole range of the blend composition. Further, it was suggested that the crys talline structure and degree of crystallinity of each component in these bl ends almost remained the same as those in the pure state. Enzymatic hydroly sis in the presence of lipase and environment degradation in river water we re also studied for these blend systems. The biodegradability of aliphatic polyester is suggested to be controllable by blending. (C) 2000 Elsevier Sc ience Ltd. All lights reserved.