Span S-20 lauric acid (CAS No.: 1338-39-2), with the chemical name sorbitan monolaurate, is a non-ionic surfactant produced by Guoli Chemical. The product appears as an amber to light yellow viscous liquid or waxy solid, with a typical fatty ester odor, and is an excellent water-in-oil emulsifier.
The HLB value of this product is approximately 8.6, classifying it as a lipophilic emulsifier. It is soluble in oils and organic solvents and disperses in water to form an emulsion. Its surface tension is about 28 mN/m, with a critical micelle concentration (CMC) of approximately 2.5×10⁻⁵ mol/L, demonstrating good interfacial activity. The product has excellent chemical stability, remaining stable under normal conditions and maintaining activity even in weak alkaline media. It is characterized by low foaming and low hygroscopicity.
The product has an active content of no less than 99%, with monoester content ≥95%, diester content ≤5%, and free alcohol ≤2%, ensuring high purity. The molecular formula is C18H34O6, with a molecular weight of 346.46. All indicators meet the excipient standards required for high-end applications such as food, pharmaceuticals, and cosmetics.
| Parameter Item | Index Value |
|---|---|
| Chemical Name | Sorbitan monolaurate (sorbitan monododecanoate) |
| CAS Number | 1338-39-2 |
| Molecular Formula | C18H34O6 |
| Molecular Weight | 346.46 |
| Appearance | Amber to light yellow viscous liquid or waxy solid |
| Ionic Type | Non-ionic |
| HLB Value | 8.6 |
| Active Content | ≥99% |
| Monoester Content | ≥95% |
| Diester Content | ≤5% |
| Free Alcohol | ≤2% |
| Acid Value | ≤7.0 mgKOH/g |
| Saponification Value | 155~170 mgKOH/g |
| Hydroxyl Value | 330~360 mgKOH/g |
| Iodine Value | ≤10 |
| Moisture Content | ≤1.5% |
| pH of 1% Aqueous Solution | 5.0~7.0 |
| pH of 5% Aqueous Solution | 5.0~7.0 |
| Density | Approximately 1.0~1.1 g/cm³ |
| Kinematic Viscosity (Low Shear) | Approximately 4000~6000 mPa·s |
| Refractive Index | Approximately 1.47~1.48 |
| Melting Point | <10°C |
| Flash Point | >150°C |
| Cloud Point | Approximately 25°C |
| Surface Tension | Approximately 28 mN/m |
| Critical Micelle Concentration (CMC) | Approximately 2.5×10⁻⁵ mol/L |
| Foaming Property | Low foaming |
| Hygroscopicity | Low hygroscopicity |
| Chemical Stability | Stable under normal conditions |
| Alkali Resistance | Stable in weak alkali |
| Heavy Metals | ≤20 ppm |
| Arsenic | ≤2 ppm |
| Solubility | Soluble in oils and organic solvents; disperses in water to form an emulsion |
| Packaging Specifications | 50kg / 200kg plastic drum |
As a lipophilic emulsifier, Span S-20 lauric acid is typically used in combination with hydrophilic surfactants (such as the Tween series) to achieve a wider HLB adjustment range and more stable emulsification effects. In cosmetic cream formulations, the recommended dosage is 1%~5%; in pesticide emulsifiable concentrate systems, it can be combined with hydrophilic emulsifiers to promote spontaneous emulsification; in food baking oils, the recommended dosage should comply with GB 2760 standards.
When applied in pharmaceutical preparations and the food industry, it is necessary to confirm that the product meets the corresponding pharmacopoeia or food additive standard batches. The product has a monoester content ≥95%, and its high purity ensures superior performance in sensitive formulations.