The dielectric relaxation behavior of a high molecular weight poly(P-h
ydroxybutyrate) (PHB) synthesized through Azotobacter chroococcum 23 w
as investigated by measuring the complex dielectric permittivity over
wide frequency and temperature ranges. PHB exhibits two dielectrically
active processes in the temperature and frequency ranges investigated
. The higher temperature relaxation a has been attributed to motions t
hat appear at temperatures above the glass transition temperature T-g.
The low-temperature process beta is thought to be due to local motion
of carboxyl groups and local rotations around the C-O bond. The pheno
menological Havriliak-Negami (HN) description has been applied to anal
yze the dielectric loss data and to extract the shape parameters of th
e above relaxations in an attempt to correlate experimental data to dy
namics of relaxation processes.