| The green catalytic synthesis routine of sulfonic gemini surfactant-sodium 1,4-butanediol bisulfosuccinate diester catalyzed by solid supported phosphotungstic acid has been investigated in this paper.Firstly, phosphotungstic acid supported on TiO2 and SiO2 particles were prepared by adsorption technique using TiO2 or SiO2 as carriers, which were prepared by sol-gel method. The effects of reaction parameters such as the mass ratio of carrier to PW12, concentration of PW12, reflux time, activation temperature were studied by using synthesis of 1,4-butanediol bismaleic acid diester as a probe. The solid catalyst was studied by IR, XRD and specific surface area, and the degree of fastness between phosphotungstic acid and carriers was investigated through study of the desorption of them in different solvents. A higher production rate and activity of the product can be achieved when the mass ratio of SiO2 to PW12 was 1:3 and TiO2 to PW12 was 1:2, concentration of PW12 was 0.10 mol/L, reflux time was 4 h and activation temperature was 150℃, Keggin structure was preserved when phosphotungstic acid was supported on the carrier. As phosphotungstic acid immobilized increased, highly dispersed phase of phosphotungstic acid on the carrier gradually changed into the accumulation phase, and specific surface area decreased, while the volume of dissolved increased in polar solvent.Secondly, Sodium 1,4-butanediol bisulfosuccinate diester was prepared through esterization and sulfonation using 1,4-butanediod, maleic anhydride and 1-octadecanol as principal raw material. The optimum conditions for duble esterification are confirmed through single factor and orthogonal experiments. the esterification rate of 97.2% and the yield of 84.9% was obtained in 8h at 150℃,when the ratio of 1,4-butanediol bismaleic acid monoester to 1-octadecanol was 1.00:2.20, the dosage of the catalyst was1.5%. Products were studied by IR, 1HNMR. The esterification rate remained relatively high(90%) after the catalyst was reused for 6 times, which indicates the solid catalyst shows an excellent re-use performance. 92.7% of the sulphonation rate and up to 74.9% of the yield was reached in 4h at 90℃, when the molar ratio of 1,4-butanediol bismaleic acid diester to NaHSO3 was 1.00:3.00 and 1.5% catalyst. And the product was characterized through IR spectroscopy.Finally, the surface activity of sodium 1,4-butanediol bisulfosuccinate diester was measured by ring detachment method. Surface Tensionγcmc was 41.9mN/m, cmc was 7.2×10-5mol/L in aqueous solution at 25℃, which indicated the surfactant had a low minimum micelle concentration.
|
PDF Full Text Request