Preparation method of long-chain alkyl silicone oil

The invention provides a preparation method of long-chain alkyl silicone oil, which comprises the following steps: sequentially adding vinyl silicone oil, pentanethiol, benzoin dimethyl ether and a solvent tetrahydrofuran into a reaction tube, then stirring and reacting for 2-3 hours under the irradiation of an ultraviolet lamp, and obtaining a crude product after the reaction is finished; and carrying out reduced pressure distillation on the crude product, removing the solvent, washing and purifying with methanol, and then carrying out vacuum drying at 50 DEG C for 24-30 hours to obtain the long-chain alkyl silicone oil. The long-chain alkyl silicone oil is prepared through the sulfydryl double-bond reaction of the vinyl silicone oil and the long-chain alkyl mercaptan, and the method has the characteristics of high reaction speed, high directional selectivity, mild reaction conditions, high reaction adaptability, environmental protection, safety, low cost and the like. 本发明提供了一种长链烷基硅油的制备方法：在反应管中，依次加入乙烯基硅油、戊硫醇