Molecular motions in glassy polycarbonate below its glass transition temperature

We have investigated the motion of different molecular groups in glassy polycarbonate below its glass transition temperature. The characterization of methyl group and phenylene ring motions on the one hand, and carbonate group on the other, were carried out by means of neutron scattering and dielectric spectroscopy respectively. The comparison of the results from both the techniques indicate that different motions within polycarbonate may be strongly coupled.