Hr. Brand et K. Kawasaki, MODE-COUPLING THEORY OF THE ISOTROPIC-NEMATIC TRANSITION IN SIDE-CHAIN LIQUID-CRYSTALLINE POLYMERS, Journal de physique. II, 4(4), 1994, pp. 543-548
Using a mode coupling technique we investigate the dynamics near the i
sotropic-nematic transition in liquid crystalline sidechain polymers.
While in mean field approximation one obtains z = 1 for the dynamical
critical exponent z for the relaxation time of the order parameter, we
get from mode coupling the value z = 1.5, a result which is in agreem
ent with recent experiments done in Martinoty's group on two different
classes of sidechain liquid crystalline polymers using electric and a
coustic birefringence measurements. An analysis of recent measurements
of the dynamic stress-optical coefficient in sidechain elastomers sho
ws that mode coupling effects are also important in that case.