Stearate Polyoxyethylene Ether SG-9 is a nonionic surfactant with an HLB value of approximately 11–12. Its core characteristics lie in its excellent emulsifying ability, broad compatibility, superior resistance to acids, alkalis and hard water, as well as its multiple functions including wetting, dispersing, solubilizing, antistatic and softening. It is widely used in textiles, personal care, metalworking, agrochemicals and other industrial fields.
Detailed Description
Stearate Polyoxyethylene Ether SG-9 (PEG-9 Stearate) is produced by the addition reaction of stearic acid with ethylene oxide. It appears as a white to slightly yellowish waxy solid. As a typical nonionic surfactant, its molecular structure contains both hydrophilic polyoxyethylene chains and lipophilic stearate groups, enabling it to effectively reduce oil/water interfacial tension and form stable, fine emulsion systems. It plays a key role in emulsification and stabilization in various formulations.
The greatest advantage of this product is its multifunctional integration—a single product can provide emulsifying, solubilizing, antistatic, softening and other functions, helping to simplify formulation design and reduce the number of raw materials. With an HLB value of about 11–12, it is particularly suitable for constructing oil-in-water (O/W) emulsion systems and imparts a soft, non-greasy skin feel, which is especially favored in cosmetic creams and lotions as well as textile finishing.
As a nonionic surfactant, SG-9 can be freely combined with anionic, cationic and other nonionic surfactants without restriction by ionic type, offering extremely broad compatibility. It maintains stable performance over a wide pH range and remains effective in emulsifying and wetting under hard water conditions, being less susceptible to calcium and magnesium ions—an advantage not shared by many anionic surfactants. In addition, this product is readily biodegradable (OECD 301B method, degradation rate >60%), making it environmentally friendly.
Technical Parameters
| Parameter | Specification |
|---|
| Chemical Name | Polyoxyethylene (9) Stearate |
| Synonyms | Polyethylene Glycol Monostearate, PEG-9 Stearate, Polyethylene Glycol Monostearate (9 EO) |
| CAS No. | 9004-99-3 |
| Product Type | Nonionic Surfactant |
| Appearance | White to slightly yellowish waxy solid |
| HLB Value | Approx. 11–12 |
| Solubility | Dispersible/soluble in water, soluble in various organic solvents |
| pH Stability | Stable over a wide pH range |
| Biodegradability | Readily biodegradable (OECD 301B, >60%) |
| Acute Toxicity (LD50) | >2000 mg/kg (rat, oral), classified as low toxicity |
Application Suggestions
Based on the HLB value and functional properties of SG-9, its application scenarios cover multiple industries. Dosage and combination schemes may be adjusted according to specific requirements:
- Textile Industry: Used as an emulsifier and antistatic agent in synthetic fiber spin finishes; recommended for combination with smoothing agents to significantly reduce fiber friction and static buildup. Applied as a softening agent component in finishing processes to improve fabric hand feel and spinnability.
- Cosmetics and Personal Care: Suitable for O/W creams, lotions, cleansers and shampoo/shower products as a primary or auxiliary emulsifier at a recommended dosage of 1%–5%, helping to construct stable, fine emulsion systems and impart a soft skin feel.
- Metalworking Fluids: Acts as an emulsifier and lubricant in emulsifiable cutting fluids and grinding fluids, promoting the dispersion of oily components in water, enhancing lubricating and cooling performance, and reducing tool wear.
- Agrochemical Formulations: Used as an emulsifier in emulsifiable concentrates, aqueous emulsions and microemulsions to ensure uniform dispersion of active ingredients upon dilution, improving heat storage stability of the formulation and field emulsification performance upon dilution.
- Plastics and Rubber Industry: Used as an internal antistatic agent and slip agent, suitable for polyolefins, PVC and other products, effectively reducing surface resistivity, minimizing dust attraction, and also providing release agent effects.
Precautions
- This product may cause slight skin irritation and moderate eye irritation. When handling, it is recommended to wear chemical safety goggles and chemical-resistant gloves to avoid direct contact.
- After handling, wash hands and exposed skin thoroughly. Contaminated work clothing should not be taken outside the workplace.
- Store in a cool, dry, well-ventilated warehouse. Recommended storage temperature not exceeding 35°C. Keep containers tightly closed, protect from moisture and direct sunlight.
- Avoid co-storage with incompatible materials such as strong oxidizing agents and strong acids.
- Combustion may produce harmful gases such as carbon monoxide and carbon dioxide. Firefighters should wear self-contained breathing apparatus.
- Avoid releasing into soil, sewers, waterways and other environmental waters. Although the product is readily biodegradable, it may still pose a certain hazard to aquatic organisms (LC50 fish >10–100 mg/L, 96h).
