Method for preparing sulphated castor oil

Abstract

The invention relates to a method for preparing sulphated castor oil. The method comprises the following specific steps of: sulphating: carrying out sulphation reaction by adding a catalyst into the castor oil and dropping fuming sulphuric acid, wherein the dropping temperature is 20-28 DEG C; and the dropping time is 1-2 h; continuously reacting for 3-5 h, controlling the temperature at 28-38 DEG C, and obtaining a castor oil sulphate solution; salt washing: washing the castor oil sulphate solution by using saturated salt water to obtain salt washed castor oil sulphate; and neutralizing: neutralizing the salt washed castor oil sulphate by using ammonia water, and controlling the pH value at 7-8 to obtain the sulphated castor oil. According to the method disclosed by the invention, the catalyst is used in the castor oil sulphation process, therefore, the castor oil sulphation speed is increased; the sulphonated rate is increased; the catalyst can be recycled in the salt washing process; the sulphation reaction temperature is 20-38 DEG C; the by-products in the reaction process are reduced; the product impurities are reduced; the product performance is better; the neutralization process is easy to master by using ammonia water; and the excess neutralization is difficult.

Description

technical field [0001] The invention relates to a preparation process of anionic surfactant sulfated castor oil, in particular to a preparation method of sulfated castor oil. Background technique [0002] Sulfated castor oil, also known as Turkish red oil, is a slightly yellow to dark brown liquid with excellent foaming, emulsifying and penetrating properties, and is a good anionic surfactant. Sulfated castor oil has various uses and is widely used in textiles, leather, coatings, papermaking and other fields. [0003] There have been many reports on the properties of sulfated castor oil. In the molecular structure of castor oil, -OSO was introduced during the sulfation and neutralization process 3 NH 4 Group, its nature has undergone a qualitative change, from neutral vegetable oil to anionic surfactant, although it maintains an oily phase, it adds viscosity and transparency, due to the introduction of hydrophilic groups, sulfated Castor oil can be dissolved in water and...

AI Technical Summary

Problems solved by technology

The current preparation method of sulfated castor oil has disadvantages such as long preparation time, low sulfonation rate of the product, and more impurities in the product.

In addition, in many current methods for preparing sulfated castor oil, the temperature of the sulfation reaction of castor oil is 42°C, which causes side reactions such as hydrolysis of sulfate ester and condensation of ricinoleic acid to occur easily during the sulfation of castor oil. Product quality is not good enough

Most of the current neutralization process uses sodium hydroxide solution. Sodium hydroxide needs to be added slowly to neutralize sulfuric acid ester, and it is easy to neutralize excessively.