Comparing the phase diagrams of the three binary soap systems KCldglycerol, KC&thylene glycol and KCldbutylene glycol (KCL6 = K-palmitate), we found alterations in types of phase diagrams that depend on the chemical structure of the protic solvent. Variation of the polymorphic transitions were observed. In the binary system KCI6/ G (G = Glycerol) we observed the polymorphism: C CI G H H H L H S (C = crystalline phase, G = gel phase, H = hexagonal phase, L = lamellar phase, S = isotropic solution). In the binary system KCldE (E = ethylene glycol) we found the polymorphic transitions: C t * G H L w S . In the binary system KCI6/B (B = butylene glycol) we observed the same phase sequences: C c--f G H L H S. So we came to the conclusions that the influence, which the solution medium exerts on the formation of structures in binary systems is distinct and pronounced. Differences in number, position, extension, and in the sequence of the occurring mesophases were found as a function of the composition of mixtures and temperature.
1 . I n t r o d u c t i o n
Up to now, lyotropic mesophases have been tested mostly in binary and ternary surfactant systems or in other aqueous multicomponent system"". Therefore investigations on influences of non-aqueous solvents on the formation of lyotropic mesophases presents a new aspect in this field. In literature, we find only the very first attempts to get some information about this to pi^'^^^'. The aim of our studies was to prove the influence of ethylene glycol, butylene glycol and glycerol on the phase formation in the three binary K-palmitate/ethylene glycol-, K-palmitate/butylene glycol and K-palmitate/glycerol systems.
2 . M e t h o d s a n d S a m p l e P r e p a r a t i o n
The texture was observed by applying a polarizing microscope (Jenapol 30-0060, Carl Zeiss, Jena) equipped with a heating stage. On the average we tested 15 singular concentrations per binary system. The mixtures were investigated in so-called flat capillaries. The mixtures obtained by a special pretreatment procedures were put into the flat capillary. Then, the capillary was hermetically closed by melting at its open end.
Texture examination was performed at temperature between about T -303-623 K. Heating was carried out by means of a Mettler-Thermosystem.