Sorbitan Tri Oleate (STO)

Overview

Sorbitan Tri Oleate (STO) is a highly versatile and effective nonionic surfactant, widely recognized for its exceptional lipophilic properties and ability to stabilize complex formulations. Derived from the esterification of sorbitol with three units of oleic acid, STO is a polyol ester. Known by its INCI name: Sorbitan Trioleate and CAS Number: 26266-58-0, this tri-ester of sorbitol and oleic acid exhibits a very low HLB value (typically 1.8), making it an excellent W/O (water-in-oil) emulsifier, solubilizer, and dispersant for oil-phase ingredients.

Its robust chemical structure and high purity offered by CanCastor ensure superior performance across a broad spectrum of industrial applications, from intricate pharmaceutical emulsions to demanding industrial lubricants. CanCastor guarantees adherence to stringent quality controls, ensuring batch-to-batch consistency and compliance with international standards like REACH and relevant food-grade specifications (e.g., E492), making it a trusted ingredient for critical formulations globally. Explore our full range of specialty esters in our full catalog.

Key Physical & Chemical Properties

CanCastor's Sorbitan Tri Oleate (STO) typically exhibits the following characteristics:

• Acid Value: Max 10.0 mg KOH/g
• Saponification Value: 172-188 mg KOH/g
• Hydroxyl Value: 56-78 mg KOH/g
• Iodine Value: 75-90 g I₂/100g
• Specific Gravity (25°C): 0.950-0.980
• Color (Gardner): Max 12
• Moisture: Max 1.0 %