Study on the Synthesis and Compounding Performance of C-21 Dibasic Acid Potassium

摘要

A long-chain dibasic acid with six-membered ring, C-21 dibasic acid (C-21-DA), was synthesized with mixed fatty acid, acrylic acid as starting materials, and iodine as the catalyst and quinol as polymerization inhibitor. The product was purified by distillation under reduced pressure and characterized using mass spectroscopy (MS) and nuclear magnetic resonance spectroscopy (H-1 NMR). An anionic surfactant, C-21 dibasic acid potassium (C-21-DAP), was synthesized with KOH via neutralization reaction. The synergistic effect was investigated by mixing C-21-DAP with fatty alcohol polyoxyethylene ether with 7 ethoxy groups (AEO(7)), dodecyl trimethyl ammonium chloride (DTAC) and octadecyl dimethyl betaine (BS-18), respectively, to evaluate the surface activity. The results showed that the mixed system of C-21-DAP/DTAC possessed the best synergistic effect among all studied systems, where a minimum surface tension at the critical micelle concentration (gamma(CMC)) of 28.28 mN m(-1) was obtained. Because of the electrostatic attraction between C-21-DAP and DTAC, the repulsive force between the same kind of molecules and micelle molecules in the surface adsorption layer was indirectly reduced.