Sodium Stearate

Sodium Stearate is the sodium salt of stearic acid. It is a classic and primary component of traditional soap and functions as a versatile anionic surfactant. This white, solid powder with a slight fatty odor is insoluble in water but disperses to form a colloidal solution, which is the basis of its cleansing and emulsifying action. Beyond its role in soap-making, Sodium Stearate is a critical multi-functional additive across numerous industries, serving as a thickener, stabilizer, lubricant, and gelling agent in products ranging from cosmetics and pharmaceuticals to plastics and construction materials.

Technical Specifications

Packaging and Storage

1. Woven bag lined with high pressure PE film, 25kg/bag or follow customer’s packaging instruction.
2. Containers should be kept tightly closed and stored in a dry well-ventilated location. Avoid the accumulation of dust.

Primary Functions and Mechanism of Action

Sodium Stearate performs several key roles in formulations:

Surfactant and Cleansing Agent:
Its molecules have a hydrophobic (fat-loving) tail and a hydrophilic (water-loving) head. This structure allows it to surround and emulsify oils and grease, suspending them in water for easy removal.

Gelling Agent and Thickener:
In aqueous systems, particularly when heated and cooled, it forms gels. This property is crucial for controlling the viscosity and consistency of products like creams, deodorants, and lubricants.

Stabilizer:
It helps to prevent the separation of ingredients in emulsions and suspensions, ensuring product uniformity.

Lubricant:
It acts as a process aid and internal lubricant in the production of plastics and tablets, reducing friction during manufacturing.

Applications of Sodium Stearate

Sodium Stearate is a workhorse chemical with diverse industrial applications.

Cosmetics and Personal Care
Soaps & Bars: A primary hardening and lathering agent in traditional bar soaps and syndet bars.
Deodorants & Antiperspirants: Used as a key gelling agent to create the solid stick form.
Creams & Lotions: Functions as an emulsifier and thickener to stabilize oil-in-water emulsions.

Pharmaceuticals
Tablet Manufacturing: Serves as a lubricant to prevent powder from sticking to machinery during compression.
Ointments & Creams: Used as an emulsifying base for medicated topical applications.

Plastics and Polymers
PVC Production: Acts as an acid scavenger and lubricant, neutralizing residual HCl and improving processability.
Other Polymers: Functions as a mold release agent and processing aid.

Food Industry
Food Additive: Used as a binder, emulsifier, and anti-caking agent.

Construction and Other Industries
Cement & Concrete: Acts as an air-entraining agent, creating microscopic air bubbles that improve workability and freeze-thaw resistance.
Pencils & Crayons: Used as a binder and hardening agent.
Metalworking: Found in some cutting fluids and lubricants.

Safety and Handling Guidelines

Safety Considerations

Inhalation: Avoid creating dust. Use in a well-ventilated area. Dust may cause respiratory irritation.
Skin Contact: May cause mild irritation, especially in dry or sensitive skin. Prolonged contact should be avoided.
Eye Contact: Dust can cause mechanical irritation.
Ingestion: Low toxicity, but not intended for consumption.

Storage Recommendations

Store in a cool, dry, and well-ventilated place. Keep the container tightly sealed to prevent moisture absorption and contamination. Away from strong acids and oxidizers.

Frequently Asked Questions (FAQs)

Is Sodium Stearate natural?
It can be derived from both vegetable oils (e.g., palm, coconut) and animal fats.

What is the difference between Sodium Stearate and Stearic Acid?
Sodium Stearate is the salt formed when stearic acid is saponified with sodium hydroxide, making it alkaline and water-dispersible, which is essential for its surfactant properties. Stearic Acid is the free fatty acid (C₁₇H₃₅COOH), which is weakly acidic.

Can Sodium Stearate be used in liquid soaps?
It is not typically used in clear liquid soaps as it forms an opaque, colloidal dispersion. Potassium salts of stearate (Potassium Stearate) are more soluble and are often preferred for liquid or soft soaps.

Why is Sodium Stearate used in deodorants?
Its unique property of forming a rigid gel upon cooling from a hot melt is what gives solid stick deodorants their structure and application properties.

Where can I purchase high-quality Sodium Stearate?

You should buy Sodium Stearate from reliable suppliers. Contact us via email [email protected] for an offer.