What is dioctyl sulfosuccinate sodium salt? What are its industrial applications?

1. What is Dioctyl sulfosuccinate sodium salt?

Dioctyl sulfosuccinate sodium salt, also known as sodium docusate, penetrant OT, or rapid penetrant T, and by other English names DOSS, DSS, or Aerosol OT, is the sodium sulfonated salt of dioctyl succinate. It is one of the most potent anionic surfactants in industrial applications, and its chemical formula is typically written as:

C20H37NaO7S (Diisooctyl maleate sulfonate, CAS No.: 577-11-7, EINECS No.: 209-406-4, molecular weight approximately 444.56)

It is a white, waxy solid at room temperature, soluble in water and most organic solvents, and has a strong ability to reduce surface tension. DOSS is prepared by esterification of maleic anhydride with 2-ethylhexanol followed by sulfonation and neutralization, and is a classic succinate sulfonate surfactant.

The DOSS molecules possess a molecular framework with two 2-ethylhexyl hydrophobic chains and a hydrophilic head containing a sulfonic acid group (-SO3Na). Its special “double-tailed, single-headed” structure leads to small molecular cross-section and tight arrangement, which allows it to rapidly decrease surface tension at very low concentration. Its wetting ability is one of the best among all surfactants, hence it is nicknamed “super wetting agent.” This rapid wetting characteristic allows it to quickly spread and penetrate fabrics, powders, crop leaves and metal surfaces, thus making it a versatile agent for penetration, wetting and rewetting.

DOSS is a chemically anionic surfactant, which has good wetting, penetration, emulsification, dispersion and foaming properties. It is chemically stable and resistant to acids and alkalis. It can be formulated with most surfactants and has a low toxicity. Concentrated solutions can irritate the eyes. It must be kept in a sealed, moisture proof container.

Industrial grade DOSS – products for industrial applications such as wetting, penetration, emulsification and dispersion; Industrial-grade products pay more attention to the following indices:

Wetting properties (surface tension/wetting time)

The most important index of DOSS is wetting performance, which is carried out by reducing surface tension and wetting time, which directly determines the effect of penetration and spreading.

acid value

The acid value is a measure of the free acid present. If the acid value is too high, it will influence the stability of the formulation and the downstream applications. It should be controlled in a reasonable scope.

pH (1% aqueous solution) pH value affects product properties and formulation compatibility and must be controlled within the labelled range.

Moisture

Moisture affects product viscosity and storage stability and needs to be carefully controlled.

II.  What are the uses of industrial-grade Dioctyl sulfosuccinate sodium salt?

The special "super wetting" properties of industrial DOSS make it widely used in wetting, penetration, emulsification and dispersion.

1. Main application: penetration and wetting agents

DOSS is one of the most efficient wetting surfactant in the industrial field. It is a fast penetrating agent and can rapidly reduce surface tension and wet the substrate. This is widely used in textile printing and dyeing penetration, powder wetting, paper wetting and industrial cleaning, to improve adhesion, gloss and levelling.

2. Emulsifier for emulsion polymerisation

DOSS is used as an emulsifying agent for styrene-butadiene rubber (SBR), ABS resin and acrylic emulsion polymerisation systems. Also used for the stabilisation of latex particles and control of particle size distribution. It is an important emulsifier in the synthetic rubber and resin industries.

3. Coatings, inks and additives for pigments

DOSS is used as a wetting and dispersing agent in coatings, inks and pigments to help pigment particles get wet and disperse rapidly, prevent sedimentation and improve adhesion, gloss, colour resolution and levelling properties of coatings.

4. Printing and dyeing auxiliaries for textile

DOSS is a fast penetration agent and a scouring agent component in textile printing and dyeing. It helps the dye liquor to penetrate rapidly and uniformly into the fibre, it improves the dyeing levelness and dyeing rate. It is also used in the desizing, scouring and bleaching processes.

5. Electroplating & Industrial Cleaning

DOSS is employed as a wetting agent and degreasing penetrant in electroplating solutions to assist in the elimination of pinholes in the plating and to improve plating quality. DOSS is also utilised as a component in industrial cleaning agents and refining agents, servicing the metal processing and surface treatment industries.

6. Additives for leather and paper production

Used as a wetting and penetrating agent in leather degreasing, papermaking and other process.

7. Other Applications

With the development of green surfactants, the application scope of industrial-grade DOSS continues to expand, including applications such as forest fire extinguishing wetting agents and cosmetic makeup removers.

Summarize

Dioctyl sulfosuccinate sodium salt (also known as sodium docusate, penetrant OT, C20H37NaO7S, CAS No. 577-11-7) is a white, waxy solid or anionic surfactant supplied as a 70-75% aqueous solution. Its "double-tailed, single-headed" structure provides superior wetting ability, making it one of the strongest wetting surfactants in the industrial field. In daily life, we encounter it through cleaning and washing products, textiles and clothing, paints and inks, and electroplating products. In industry, DOSS is widely used as a wetting and penetrating agent, emulsifier in emulsion polymerization, wetting and dispersing agent for paints, inks, and pigments, penetrating and refining agent in textile printing and dyeing, penetrating and wetting aid in pesticides, and wetting and degreasing agent in electroplating. It is a super wetting agent bridging "surfactant chemistry" with "textiles, paints, and electroplating."