Miscibility and morphology of blends of isotactic and atactic poly(3-hydroxybutyrate)

Blends of microbial isotactic poly[(R)-3-hydroxybutyrate] (P[(R)-3HB]) (M n =650 000) and synthetic atactic poly[(R,S)-3-hydroxybutyrate] (P[(R,S)-3HB]) (M n =56 000 and 3400) were investigated by optical microscopy and SAXS. The spherulites of isotactic P[(R)-3HB] were volume-filled, indicating the inclusion of P[(R,S)-3HB] within the spherulites. The radial growth rate of P[(R)-3HB] spherulites decreased with increased content of P[(R,S)-3HB]