Research In Synthesis Esterification Of Linoleic Acid Over Solid Superacid Catalyst SO₄～(2-)/M_xO_y

The ethly linoleate has softens the blood vessel, the anti-cancer, regulative metabolism, the enhancement organism immunity effect. As it can prevent and control disease such as cerebral thombus, arterioclerosis, would be the new generation of raw material for medical purposes. With sulfuric acid as catalyst in the traditional production technology, causes the linoleic acid to be easy oxidation in the esterification process, then unsaturated duplex bond was destroyed in the molecular, resulted in reducing in the iodine of ethyl linoleate, finally it is difficult to guarant ethyl qualty of linoleate. The solid superacid catalyst SO₄^2-/M_xO_y has been focus in the world because of its many merits. The paper investigated that solid superacid catalyst SO₄^2-/M_xO_y was used for catalytic esterification of linoleic acid with ethanol.Series of solid superacid catalyst SO₄^2-/M_xO_y were prepared by some processe of precipitate, filtration, wash, torrefaction, immersing of H₂SO₄, calcinations. The solid superacid catalyst SO₄^2-/TiO₂ and SO₄^2-/SnO₂ were prepared by the two phase precipitation, SO₄^2-/TiO₂-SiO₂ were prepared by sol-gel method, at the same, SO₄^2-/TiO₂/La³⁺ and SO₄^2-/TiO₂ grefted zeolite were prepared. Preparation conditions of the catalyst suitable for esterification of linoleic acid over SO₄^2-/TiO₂ were 0.75mol/L immersing concentration of H₂SO₄ 4h and 450℃ calcinations temperature for 4h. With SO₄^2-/SnO₂ as catalyst, suitable condition was 2mol/L immersing concentration of H2SO4 4h and 500°C calcinations temperature for 4h. with SO₄^2-/TiO₂-SiO₂ as catalyst, suitable condition was lmol/L immersing concentration of H₂SO₄ 4h and 450°C calcinations temperature for 4h. with SO₄^2-/TiO₂/La³⁺ as catalyst, suitable condition was 0.75mol/L immersing concentration of La³⁺ H₂SO₄ 15h and 450 °C calcinations temperature for 4h. Synthesized conditions of the solid superacid SO₄^2-/TiO₂/SBA-15 was researched, the result showed good catalytic activity.The structure and acid properties of solid superacid have been characterized by XRD, BET, NH₃-TPD, FT-IR and TG-DTA techniques. The synthesize mechanism, the tructure and acid properties of each kind of solid superacid...