Macromolecular Rapid Communications, Vol.17, No.1, 43-49, 1996
Influence of crosslinking conditions on the phase behavior of a polyacrylate-based liquid-crystalline elastomer
The influence of crosslinking conditions (gamma-radiation-induced and chemical crosslinking above and below the clearing point) on the phase behavior of a liquid-crystalline polyacrylate-based elastomer is shown and discussed. The network formation in samples gamma-irradiated in the nematic phase results in an increase of the clearing point T-n-i which does not depend on the crosslinking density expressed as the ratio of weight-average molecular weight over number-average molecular weight between crosslinks <(M)over bar (w)>/<(M)over bar (c)> within a wide <(M)over bar (w)>/<(M)over bar (c)> range. The distorting action of the crosslinking agent at the same temperature leads to the opposite tendency in the change of T-n-i. Crosslinking in the isotropic phase shows a strong decrease in T-n-i.