Stearic Acid Polyoxyethylene Ether SG-40 (CAS: 9004-99-3) has a melting point of approximately 48-52°C and appears as a solid wax at room temperature. Before use, it must be heated to above 50°C to melt into a liquid, and then mixed with other components in the formulation. With its high HLB value of 16-17 and strong hydrophilicity (cloud point >100°C), it is particularly suitable for preparing oil-in-water (O/W) emulsion systems. The product has an active content of ≥99%, and the pH of a 1% aqueous solution is 5.0-7.0. It is chemically stable, resistant to acids, alkalis, and hard water.
In practical operation, it is recommended to heat SG-40 together with the oil phase components to 55-65°C. After complete melting and thorough stirring, emulsify with the water phase. For systems requiring fine emulsification (such as cosmetic creams), a homogenization emulsification process is recommended, with emulsification temperature controlled at 60-70°C. After emulsification, cool down slowly to obtain a fine and stable emulsion. SG-40 is a low-foam surfactant with good compatibility. It can be used in combination with anionic, cationic, and amphoteric surfactants to achieve synergistic effects.
SG-40 has good safety, with an acute oral toxicity LD50>5000 mg/kg. It is non-irritating to skin and eyes, and non-sensitizing. No special protection is required during use, but it is still recommended to wear gloves and goggles for basic labor protection. The product has a shelf life of 12 months and should be stored in a cool, dry environment at 5°C~35°C, avoiding storage with strong oxidants.
The following dosages are general industry reference ranges (data source: Guoli Chemical Product Database application classification combined with industry practice). The specific dosage should be determined through experiments based on the formulation system and process requirements:
| Application Field | Functional Role | Recommended Dosage (by total formulation weight) | Usage Method |
|---|---|---|---|
| Cosmetic Creams/Lotions | O/W Emulsifier, Solubilizer | 1.0% ~ 5.0% | Heat with oil phase to melt, homogenize to emulsify |
| Shampoo/Body Wash | Thickening Aid, Emollient | 0.5% ~ 2.0% | Hot addition method, add to surfactant phase |
| Textile Softener/Antistatic Agent | Softening, Antistatic, Leveling | 1.0% ~ 3.0% | Dissolve in water to prepare working solution, pad or immerse |
| Metalworking Fluids (Cutting Fluids/Grinding Fluids) | Emulsifier, Lubricating Component | 3.0% ~ 8.0% | Compound with base oil, rust inhibitor, etc., then add water to emulsify |
| Pesticide Emulsifier | Emulsifier, Dispersion Carrier | 3.0% ~ 10.0% | Mix with pesticide active ingredient and solvent to prepare emulsifiable concentrate or microemulsion |
| Paper Deinking Agent/Softener | Deinking Promotion, Paper Softening | 0.1% ~ 1.0% | Dilute and add to pulp system |
Cosmetic Systems: With an HLB value of 16-17, SG-40 is suitable for compounding with low HLB emulsifiers (such as Glyceryl Monostearate, HLB approx. 3.8) to obtain a composite emulsifier with an HLB value of 8-12, which is suitable for most creams and lotions. Its monoester content is ≥90%, providing high emulsification efficiency. The prepared cream is fine and glossy with a refreshing and non-greasy skin feel.
Industrial Systems: In metalworking fluids, SG-40 maintains long-term emulsion stability in high-salt and high-alkali formulations due to its excellent electrolyte resistance and chemical stability, making it especially suitable for full-synthetic and semi-synthetic cutting fluid formulations. In the textile industry, SG-40 imparts good antistatic properties and a soft hand feel to synthetic fibers, reducing hairiness and breakage during spinning.
Compounding Synergy: The nonionic nature of SG-40 allows it to be freely compounded with various ionic surfactants. For example, compounding with anionic emulsifiers can improve the salt tolerance stability of the emulsion; compounding with cationic softeners can improve the overall hand feel of fabric finishes.