Polyurethane (PU) exhibit very high electromechanical activity, and has a great interest for a wide range
of transducer and actuator applications. It has been recently pointed out that this strong electrostriction
may result from the phase separation. In the present work, a model taking account the PU nanostructure
is presented. In order to validate this model, three PUs of similar compositions but different soft segment
fractions have been characterized by DSC, TEM, AFM and SAXS and their electrostriction properties have
been measured. When taking into account the diameter of the hard domains (HD) and the HDeHD
distance, it is found that the model proposed well reproduces the experimental electrostriction properties
of these phase-separated PUs.