The kinetics of chain degradation of purified granules of poly(/3-hydroxybutyrate) in 3.0 N HCI at the boil were followed using gel permeation chromatography to detect changes in molecular weight of the residue. The results showed that degradation corresponded to a model of random scission of the molecules of both the crystalline shell and the non-crystalline core indiscriminately. Differential scanning calorimetry and wide-angle X-ray diffraction results demonstrated that the molecules recrystallize due to chain scission and annealing at the temperature at which degradation is performed (104.5°C). Transmission electron microscopy of enzyme-isolated, spray-dried granules revealed a retention of the surface shell throughout the reaction with conversion of the core to a porous lamellar texture.
Посилання на статтю:
Hydrolytic degradation of isolated poly(b -hydroxybutyrate) granules / C. Lauzier*, J.-F. Revol, E.-M. Debzi and R. H. Marchessault // Polymer. – 1994. – Vol 35. – P. 4156-4162.