Synthesis Of α-hydroxyl Fatty Acids And The Derivatives Of Disodium α-sulfated Fatty Acids

The development and application of oil chemicals have become the research hot spots in world wild all the time. The fatty acids are the main body and core in oil chemistry industry. By simple processing, they can be used to synthesize fatty acid methyl esters, fatty alcohols, chloro fatty acids and other base oil chemical products. Using these base oil chemical products as raw material through further chemical processing, variety fine chemicals and special-purpose chemical goods can be obtained. Theα-hydroxy fatty acids (α-HFA) are fine products in chemical industry, and they are widely used in building, packaging, cosmetics and daily chemical industry. The surfactants, which have two types of hydrophilic group -- -OSO3- and -COO-, can be synthesized withα-hydroxy fatty acids as raw material and HSO3Cl as sulfonated agent. This surfactant may be a kind of anionic surfactant which manifest some unusual properties and has a number of potential applications.In this paper,α-hydroxyl fatty acids were hydrothermally synthesized through catalytic neutral hydrolysis ofα-chloro fatty acids (α-CFA) derived directly from natural fatty acids, which is a novel green route to synthesizeα-HFA from natural fatty acids with the characteristics of high yield, low-cost and environmental-friendly. Besides, the structure ofα-HFA was identified by FTIR, GC-MS, NMR and element analysis. And the relative molecular weight was confirmed by ESI-MS. The purity of purifiedα-HFA was examined by GC as high as 99%. Moreover, the influence of molar ratios of reactants, water dosages, reaction temperatures and reaction time on the catalytic hydrothermal synthesis had been studied. The results indicated that the yield ofα-hydroxyl natural fatty acid (C12~C18) could reach 98%~99% under the following conditions: n(CaCO3): n(α-CFA) = 1.05:1; m(KI): m(α-CFA)= 1:100; m(H2O): m(α-CFA) = 2.5:1 at 160 oC for 4.5 h. In the process of enlargement test,α-CDA also had high hydrolysis yields.In this paper, a kind of novel anionic surfactants disodiumα-sulfated fatty acids(DSFA) were synthesized fromα-hydroxyl fatty acids undergoing sulfation with chlorosulfonic acid followed by neutralization with NaOH. The structure and purity of DSFA were examined by FTIR, NMR, element analysis and two-phase titration with Hyamine 1622, etc. The purity of purified DSFA was examined as high as 99%. Various synthesis methods of DSFA were studied in this paper, and a appropriate method for preparing DSFA was choosed. The results showed that the yield of DSFA could reach more than 91% under the following conditions: n(α-HFA): n(HSO3Cl) = 1:1.2, n(DMF): n(HSO3Cl) = 1.5:1, m(α-HFA): m(ClCH2CH2Cl) = 1:10, the HSO3Cl-DMF dipping temperature was 60oC, and the aging temperature was 70oC for 1.5 h.The Krafft point, surface tension, lime soap dispersing power and calcium ion stability of DSFA were measured in this paper. The low Krafft point of the DSFA infer us that the seven-membered-ring formed by DSFA intramolecular hydrogen bond is an unstable structure, and the DSFA perform better cold water-soluble than its analogues of disodiumα-sulfo fatty acids.