D. Tuma et al., Comparative solubility investigations of anthraquinone disperse dyes in near- and supercritical fluids, FLU PH EQUI, 182(1-2), 2001, pp. 133-143
The present study covers equilibrium solubilities of a homologous series of
1,4-bis-(alkylamino)-9,10-anthraquinones (with alkyl from methyl to octade
cyl) and additionally of the more polar anthraquinone derivatives 1-amino-1
-hydroxy-2-phenoxy-9,10-anthraquinone (C. I. Disperse Red 60) and 1,4-diami
no-2-methoxy-9,10-anthraquinone (C. I. Disperse Red 11) in several near- an
d supercritical fluids. The solubilities of the 1,4-bis-(alkylamino) substi
tuted anthraquinones except the octadecyl-derivative were measured by means
of a supercritical fluid chromatograph (SFC) between 299 and 346 K and up
to a maximum pressure of 20 MPa. On the contrary, the measurements of 1,4-b
is-(octadecylamino)-9,10-anthraquinone as well the two Disperse Red represe
ntatives 60 and 11 were performed using a static optical high-pressure auto
clave within pressures from 7 to 180 MPa and temperatures up to 400 K. We r
eflected on the results from three different points of view, namely the inf
luence of different substituents, of the particular solid state, and of dif
ferent solvent gases. A complex pattern of interrelations of these paramete
rs determining equilibrium solubilities opened; decoupling and a separate v
iew proved to be insufficient. (C) 2001 Elsevier Science B.V, All rights re
served.