SURVEY ON TRANSPORT-PROPERTIES OF LIQUIDS, VAPORS, AND GASES IN BIODEGRADABLE POLY(3-HYDROXYBUTYRATE) (PHB)

The transport properties of carbon dioxide, water, and different organ ic solvents in bacterial poly(3-hydroxybutyrate)(PHB) at 30 degrees C were investigated. CO2 sorption was measured by the gravimetric method using a recording microbalance at subatmospheric pressures. Results w ere adequately interpreted in terms of Henry's law. Organic solvent an d water permeabilities for both vapors and liquids were measured using a gravimetric cell. The data were interpreted in different terms depe nding on the units in which permeability was measured. Most of the sol vent-polymer systems showed the typical time-lag plot, but in liquid p ermeation experiments, some anomalous behaviors were observed, with a transient period of rapid permeation at the beginning of the experimen t before reaching the steady state. The transport properties of PHB we re compared with those of other polymers, either from synthetic or bio degradable origin. (C) 1997 John Wiley & Sons, Inc.