Sodium lauryl sulfate is an anionic surfactant, a typical representative of sulfate ester surfactants, referred to as SDS, also known as AS, K12, sodium cocoyl sulfate, sodium lauryl sulfate, foaming agent, market The products sold on the website are usually white to slightly yellow crystalline powder, non-toxic, slightly soluble in alcohol, insoluble in chloroform and ether, easily soluble in water, good compatibility with anions and non-ions, and good emulsification and foaming properties. It has good foaming, penetration, decontamination and dispersion properties, rich foam, and fast biodegradation, but its water solubility is inferior to fatty alcohol polyoxyethylene ether sulfate sodium (referred to as AES).
It is not sensitive to alkali and hard water, but its stability under acidic conditions is inferior to that of ordinary sulfonates, close to AES. Long-term heating should not exceed 95°C. Its irritation is at a medium level among surfactants. The irritation index of 10% solution is 3.3. Higher than AES, lower than sodium dodecyl benzene sulfonate (LAS for short). The toxicity LD50 is 1300mg/kg. There is currently no evidence that this product is carcinogenic. High doses may indeed irritate the skin. However, when used as a foaming agent in general sanitary products, the concentration is limited and it complies with the standards of various countries around the world, so there is no need to worry. Sodium lauryl sulfate is the main ingredient in dish soap. It is often used in the DNA extraction process to denature proteins and separate them from DNA. Often mispronounced as sodium lauryl sulfonate. As a foaming agent, it is widely used in toothpaste, soap, body wash, shampoo, laundry detergent, and cosmetics. Sodium lauryl sulfate is found in 95% of personal skin care products and household cleaning products.
There is a certain degree of confusion and misuse between the two. Both are anionic surfactants, and their English abbreviations are SDS. Sodium dodecyl sulfate is referred to as SDS, and it is also called sodium lauryl sulfate, referred to as SLS. It is a sulfate ester salt. , molecular weight 288, white or light yellow crystal, easily soluble in water, sodium dodecyl sulfate SDS, a sulfonate, molecular weight 272.38, the structural difference between sodium dodecyl sulfate and sodium dodecyl sulfate is dodecane Sodium sulfonate has one less oxygen atom, and the carbon atom is directly connected to the sulfur atom. Pay attention to the difference between the two to prevent misuse.
(FDA, §172.822, 2000, mg/kg): dry egg whites 1000; frozen egg whites 125; liquid egg whites 125; marshmallow foaming agent, 0.5% of the amount of gelatin used; as surfactant for acidification by fumaric acid Solid beverages and fruit juice drinks acidified with fumaric acid, 25; as a moisturizer for oils and fats, 10 (fat amount). According to the regulations of (FDA, §172.210, 2000), it can be used as a surface coating agent for citrus fruits, and the dosage is limited to GMP.
Sodium lauryl sulfate has excellent decontamination, emulsification and foaming properties. It can be used as a detergent and textile auxiliary. It can also be used as anionic surfactant, toothpaste foaming agent, mine fire extinguishing agent and fire extinguisher foaming agent. Agent, emulsion polymerization emulsifier, pharmaceutical emulsifying and dispersing agent, shampoo and other cosmetic products, wool detergent, detergent for fine silk and wool fabrics. Flotation agent for metal mineral processing.
There are many methods for preparing sodium lauryl sulfate, and the following two are currently most commonly used. The sulfur trioxide method reaction device is a vertical reactor. Nitrogen was introduced into the reactor through the gas vent at 32°C. The nitrogen flow rate is 85.9L·min-1. Pass lauryl alcohol at 82.7kPa, with a flow rate of 58g·min-1. The liquid sulfur trioxide is passed into the flash evaporator at 124.1kPa, the flash evaporation temperature is maintained at 100°C, and the sulfur trioxide flow rate is controlled at 0.9072kg·h-1. Then, the sulfation product is quickly quenched to 50°C, put into the aging device, and left for 10 to 20 minutes. Finally, put it into the neutralization kettle and neutralize it with alkali. The neutralization temperature is controlled at 50°C, and when the pH value reaches 7 to 8.5, the material is discharged to obtain the finished liquid product. The solid product is obtained by spray drying. Chlorosulfonation batch method Put lauryl alcohol into the reaction kettle and preheat to 30°C.
Then under high-speed stirring, 0.03 mol excess of chlorosulfonic acid than the theoretical amount was sprayed into the alcohol in the form of mist. The reaction temperature is controlled at 30-35°C. After the sulfation reaction is completed, put it into a neutralization kettle and neutralize it with 30% alkali solution to a pH value of 7 to 8.5. Finally, bleach with 0.4% (mass) hydrogen peroxide. Spray dry the solid. It can also be prepared into a solution according to quality standards. The continuous reaction device is a tubular reactor. First, lauryl alcohol is saturated with hydrogen chloride. Lauryl alcohol enters the saturation chamber through the meter at a flow rate of 334g·min-1 and hydrogen chloride at a flow rate of 40.5g·min-1. Then, the hydrogen chloride solution of lauryl alcohol was passed into the reactor at 21.4°C to react with chlorosulfonic acid. After the reactants are separated from gas and liquid, the sulfated product flows from the bottom of the separator into the neutralization kettle. Neutralize with 30% sodium hydroxide at 50°C to obtain a liquid product. Spray dry solid product.
