Abstract
Shape memory effects of uniaxially deformed smectic C* (SmC*) elastomers are investigated for two different types of crosslinker, namely a hydroquinone-type crosslinker and a rod-like crosslinker. Mesogens are allowed to tilt during the SmA-SmC* phase transformation in the elastomer synthesized with the hydroquinone-type crosslinker. As for the elastomer with the rod-like crosslinker, however, the smectic layers are tilted during the transformation, because the rod-like crosslinker is enough rigid to disturb mesogens in tilting. Since the shape change of the elastomer is coupled to the transformation of the molecular alignment, the elastomer synthesized with the hydroquinone-type crosslinker elongates with increasing temperature in SmC* because of the decrease of molecular tilt angle, while the sample length of the elastomer with the rod-like crosslinker is almost constant during the temperature range of SmC* despite the re-arrangement of layer structure. Both of the elastomers exhibit reversible shape change which respectively corresponds to reversible change of molecular alignment in a heating and cooling process within successive phase transitions between the isotropic phase and the smectic C phase.
