Acid Soap and Phase Behavior of Stearic Acid and Triethanolamine Stearate

Abstract

Crystals of partially neutralized stearic acid with triethanolamine (TEA) were prepared by mixing these two materials above 80 degrees C and then cooling. The crystalline composition and the structure and melting behavior of the resultant products were characterized with small-angle and wide-angle X-ray diffraction, thermal analysis, microscopy, and infrared spectroscopy. It was discovered that an acid-soap complex of 2:1 fixed stoichiometric ratio exists between stearic acid and TEA stearate. A binary phase diagram of stearic acid and TEA soap is built based on the experimental results; this is the first published record of a binary phase diagram for amine-based soap. Its behavior is significantly different from that of binary systems of fatty acid and alkali soap.

Structural and Thermal Properties of Unpurified and Purified 12-Hydroxystearic Acid Solutions

“…3(b). The spacing estimated from this peak position is very close to that of SA reported by other researchers [15][16][17]. These facts suggest that dominant materials of the impurity in u-12-HSA are stearic acid produced in a side reaction of hydrogenation process [8].…”

Method for analysis of the composition of acid soaps by electrolytic conductivity measurements

“…As known, with the increase of the total carboxylate concentration, c t , different kinds of solid precipitates (HZ and j:n acid soaps) and micelles appear in the aqueous carboxylate solutions [3,[12][13][14][19][20][21]. The electrolytic conductivity of these solutions, κ, may exhibit one or more kinks when plotted as a function of c t [21,22,[28][29][30].…”

“…The acid soaps were investigated by Ekwall [5][6][7][10][11][12], McBain et al [8,9], and in subsequent studies [3,4,[13][14][15][16][17][18][19][20][21]. Soaps of different stoichiometry, j:n = 1:1, 1:2, 2:1, 3:2, 4:1, etc., have been experimentally detected [3,[12][13][14][19][20][21]. In fact, the turbidity of the soap solutions is due to the formation of fine (micrometer and submicrometer) j:n acid-soap crystallites.…”

Synthesis of poly(D,L‐lactic acid) modified by triethanolamine by direct melt copolycondensation and its characterization

“…Its amino basicity, strong hydrophilicity, and hydroxyl reaction performance make it to form ester with a variety of higher fatty acid, and the products are biodegradable surfactants, which could be used as the green softening, fabric conditioning agent, and so on. [8][9][10][11] Therefore, it is possible to get a novel PLA material with the improved hydrophilicity by the modification of TEA.…”