The phase formation and thermodynamic properties of side group copolymers c
omposed of different concentrations of mesogenic azobenzene side groups and
non-mesogenic side groups were investigated. Such kinds of polymers can be
used for optical data storage. The storage process is caused in this case
by a light-induced reorientation of the chromophores. The basic idea was th
at the introduction of non-mesogenic units should lead to frustration effec
ts in the sense that amorphous polymers are obtained, which can be handled
more easily than liquid crystalline polymers yet which still possess strong
orientational interactions between the side groups allowing cooperative sw
itching processes. The results of thermodynamic, structural and dynamical i
nvestigations indicate that this goal can be achieved on the basis of such
copolymers.