The chemical name of Span S-60 is Sorbitan Monostearate (also known as sorbitan monostearate), CAS number 1338-41-6, molecular formula C₂₄H₄₆O₆, molecular weight approximately 430.61. It is produced by intramolecular dehydration of sorbitol to form sorbitan (mainly 1,4-sorbitan), followed by monoesterification with stearic acid, and belongs to the class of polyol fatty acid ester nonionic surfactants.
From the compositional perspective, the effective active content of Span S-60 produced by Guoli Chemical is ≥98%, with the core emulsifying monoester content ≥80%, diester and polyester content controlled at ≤20%, free alcohol (unreacted sorbitol or sorbitan) ≤1%, and moisture ≤1.5%. The total solid content is ≥99%, appearance is a white to light yellow waxy solid, with a melting point range of 52~57°C.
This product has an HLB value of 4.7, making it a lipophilic emulsifier suitable for preparing stable water-in-oil (W/O) emulsion systems. Its saponification value is 145~160 mgKOH/g, hydroxyl value 230~270 mgKOH/g, and acid value ≤10 mgKOH/g. These indicators reflect the degree of esterification and the number of free hydroxyl groups in the molecule, serving as key control parameters for product quality and batch consistency. The iodine value is ≤2, indicating a very high saturation of the fatty acid chain, which endows the product with good oxidative stability.
| Parameter Item | Specification |
|---|---|
| Chemical Name | Sorbitan Monostearate |
| CAS Number | 1338-41-6 |
| Molecular Formula | C₂₄H₄₆O₆ |
| Effective Content | ≥98% |
| Monoester Content | ≥80% |
| Diester and Polyester Content | ≤20% |
| Free Alcohol | ≤1% |
| Moisture | ≤1.5% |
| HLB Value | 4.7 |
| Acid Value | ≤10 mgKOH/g |
| Saponification Value | 145~160 mgKOH/g |
| Hydroxyl Value | 230~270 mgKOH/g |
| Iodine Value | ≤2 |
| Melting Point | 52~57°C |
| Appearance | White to light yellow waxy solid |
With its chemical structure of sorbitan monostearate, Span S-60 is widely used in the following scenarios: