Method for synthesizing di-[propyltriethoxysilane]-tetrasulfide

The invention discloses a method for synthesizing di-[propyltriethoxysilane]-tetrasulfide, which comprises the following steps of: (1) mixing and stirring water, sodium sulfide, sodium hyposulfate, elemental sulfur and diethyl hydroxylamine, pumping n-amylamine and isobutylamine into the mixture under the vacuum degree of 0.04 to 0.06MPa, and reacting the mixture for 20 to 40 minutes at the temperature of between 30 and 50 DEG C; (2) adding dodecyltrimethylammonium chloride, tetrabutyl ammonium bromide and hydroxy pyridine into the reaction solution obtained in the (1) under normal pressure, stirring the solution, then adding gamma-chloropropyltriethoxysilane into the solution, reacting the solution for 30 to 60 minutes at the temperature of between 40 and 50 DEG C, continuously reacting the solution for 60 to 80 minutes at the temperature of between 60 and 80 DEG C, filtering the oil phase, and pumping the filtrate into a distillation still; and (3) distilling the filtrate in the distillation still under the