Sm. Clarke et Em. Terentjev, SLOW STRESS-RELAXATION IN RANDOMLY DISORDERED NEMATIC ELASTOMERS AND GELS, Physical review letters, 81(20), 1998, pp. 4436-4439
Randomly disordered liquid crystalline elastomers align under stress.
We study the dynamics of stress relaxation before, during, and after t
he polydomain-monodomain transition. The results for different materia
ls show a universal logarithmic behavior, especially pronounced in the
region of the transition. The data are approximated very well by an e
quation sigma(t) - sigma(eq) similar to 1/(1 + alpha ln t). We propose
a theoretical model based on the cooperative mechanical resistance fo
r the reorientation of each domain, attempting to follow the soft-defo
rmation pathway.