How to use Span S-80? What is the recommended dosage?

Span S-80 is a low HLB value (4.3) water-in-oil nonionic emulsifier, which usually needs to be heated and dissolved in the oil phase before use. The recommended dosage is generally 1%~5% based on the total formulation weight, and the specific amount needs to be determined through experiments according to the formulation system.

Detailed Instructions

Span S-80 (Sorbitan monooleate) is a classic oil-soluble surfactant produced by Guoli Chemical. At room temperature, it appears as an amber to brown viscous liquid (solidification point 10~12°C), is difficult to dissolve in water, but is easily soluble in mineral oils, vegetable oils, and most organic solvents. Its core function is to serve as a water-in-oil (W/O) emulsifier in oil-water systems, with an HLB value of only 4.3, especially suitable for stably dispersing the water phase in a continuous oil phase.

Before use, it is recommended to add Span S-80 to the oil phase components of the formulation, heat to 40~60°C, and stir evenly until fully dissolved. If the product solidifies due to low ambient temperature, the container can be placed in a warm water bath to preheat and restore fluidity before use. Direct heating with an open flame is strictly prohibited. When preparing the emulsion, slowly add the water phase to the oil phase containing Span S-80 while undergoing high-speed stirring or homogenization to obtain a stable water-in-oil emulsion. To adjust the hydrophilic-lipophilic balance of the emulsification system, Span S-80 can be compounded with high HLB value Tween series (such as Tween T-80, HLB=15.0) to achieve the target HLB value.

The determination of dosage needs to consider factors such as the oil-to-water ratio, the type of emulsion required, and viscosity. Too low a dosage cannot form a stable emulsion, while too high a dosage may cause the system to be overly viscous or increase formulation costs. It is recommended to conduct gradient experiments (e.g., 0.5%, 1%, 2%, 5%) to observe emulsion stability and select the optimal dosage.

Application Recommendations

General recommended dosage in various fields (as weight percentage of total formulation):

Note: The above dosages are industry general reference ranges. The optimal dosage should be determined through experiments based on specific formulation and process conditions.

Precautions

• Compounding Recommendation: Using Span S-80 alone can only form W/O emulsions. To prepare O/W emulsions, it must be compounded with high HLB value emulsifiers (such as Tween series), and the ratio should be calculated by weighted average based on HLB values.
• Temperature Control: When preparing emulsions, it is recommended to keep the oil phase and water phase at the same temperature (usually 60~70°C). Excessive temperature difference can lead to instability of the primary emulsion.
• Protective Requirements: Span S-80 is classified as a skin/eye irritant (H315/H319). Protective gloves and goggles should be worn during operation, and ensure good ventilation. For specific safety matters, please refer to the Safety Data Sheet.
• Storage Conditions: The product should be stored in a tightly sealed container in a cool, dry place, with temperature below 40°C. Seal the container promptly after use to prevent moisture absorption or contamination.