Dynamics of a glassy polymer studied by Brillouin light scattering

The propagation and damping of acoustic modes in glassy polymethylacrylate are studied by means of Brillouin light scattering technique. An overview of the experimental setup and of the data acquisition and analysis developed by our group is briefly given. The temperature behavior of characteristic frequency and linewidth of Brillouin peaks gives evidence of two main relaxation processes active in the 10 GHz frequency region of the glassy polymer, assigned to the rotation of side-chain groups and to the interaction of acoustic waves with thermal vibrations.