TEXTURE EVOLUTION DURING THE POLYDOMAIN-MONODOMAIN TRANSITION IN NEMATIC ELASTOMERS

We have studied the behavior of a liquid crystalline elastomer undergo ing a polydomain-monodomain transition. The textures emerging under in creasing extensional load have been examined with a combination of opt ical microscopy, X-ray, and small-angle polarized light scattering. Th e experimental data are interpreted in terms of reorientation of the l ocal director with increasing extension. The results of this combinati on of techniques at low extensions are consistent with a two-dimension ally periodic director texture. The amplitude of this modulation decre ases continuously as the mesogens are pulled into the extensional dire ction at high loads. In this manner the samples which are polydomain u nder no load become essentially monodomain with increasing extension.