POLY(HYDROXYBUTYRATE) INVIVO - NMR AND X-RAY CHARACTERIZATION OF THE ELASTOMERIC STATE

Variable-temperature C-13 NMR relaxation studies of whole cells of Alcaligenes eutrophus show that poly(beta-hydroxybutyrate) (PHB) is an amorphous elastomer in its "native" state within granules. The in vivo T(g) is estimated be around -40-degrees-C. Rotational correlation times and Arrhenius and other kinetic parameters are all consistent with amorphous elastomers that have been well characterized as bulk polymers. X-ray powder diffraction patterns of whole cells confirm that essentially 100% of PHB in its native state is amorphous.