Sorbitan monooleate, also known as Span 80, is a high molecular weight emulsifier and surfactant. It is used in many applications, including food, pharmaceuticals, cosmetics, paints, and agricultural products. It is also used as an antioxidant and preservative. Sorbitan monooleate is a derivative of sorbitol and oleic acid. It acts as a stabilizer in oil-in-water emulsions, foamers, and antifoams. It can be used with a range of different emulsifiers and surfactants to create a more stable or a more effective emulsion.
This product has excellent oil solubility and anti-rust performance for ferrous metals.
It is a kind of excellent anti-corrosion additive which has good composite effect with sulfonate salts and certain degree of bright performance.
This product also has emulsification performance on oil products.
This product is not only used to blend the operation procedure anti-rust oil and sealed anti-rust oil,but also can be used as emulsifiers of metal processing oil and lubricants diffusant,as well as secondary brightener of quenching oil.
🧪 What Is Sorbitan Monooleate?
Sorbitan monooleate (commonly known as Span 80) is a nonionic surfactant and emulsifier, widely used in lubricants, greases, and many industrial applications.
🧬 Chemical Identity:
| Property | Description |
|---|---|
| Chemical Formula | C₂₄H₄₄O₆ |
| CAS Number | 1338-43-8 |
| INCI Name | Sorbitan Oleate |
| HLB Value | ~4.3 (lipophilic) |
| Appearance | Amber viscous liquid |
| Solubility | Oil-soluble, insoluble in water |
It’s made by esterifying oleic acid (C18:1) with sorbitol.
Key Functions in Lubricants and Industry:
| Application Area | Function |
|---|---|
| Lubricants | Emulsifier for water-in-oil or oil-in-water lubricants |
| Metalworking fluids | Stabilizes emulsions, helps wet metal surfaces |
| Greases | Improves fiber structure and consistency in calcium/lithium greases |
In Lubricant Formulations:
Sorbitan monooleate is often used with:
- Ethoxylated derivatives (e.g. polysorbates/Tween)
- Calcium sulfonate greases for better water resistance
- Bio-based lubricants due to its natural origin
Example Use Case in Grease:
5% Sorbitan monooleate in calcium sulfonate complex grease:
→ Improves water resistance
→ Enhances thickener structure
→ Reduces oil bleeding
📦 Specifications (Typical):
| Parameter | Value |
|---|---|
| Acid value | < 10 mg KOH/g |
| Saponification value | 140–160 mg KOH/g |
| HLB value | ~4.3 |
| Density (25°C) | ~0.98 g/cm³ |
| Flash point | > 200°C |