G-18 glycerol polyoxyethylene ether (INCI name: Glycereth-18, CAS number: 31694-55-0) has a core component of a single nonionic surfactant—polyoxyethylene (18) glyceryl ether. It is produced by addition polymerization of natural glycerol (propane-1,2,3-triol) as the initiator with ethylene oxide (EO), with an average degree of ethoxylation n≈18. The general reaction formula can be expressed as: C₃H₅(OC₂H₄)n(OH)₃₋n, where the average value of n is approximately 18.
From the molecular structure, the product possesses both a glycerol backbone (hydrophilic basis) and polyoxyethylene long chains. The glycerol part retains some hydroxyl groups (—OH), while the polyoxyethylene chain introduces a large number of ether bonds (—C—O—C—), together endowing the product with excellent hydrophilicity, solubilizing ability, and interfacial activity. The product appears as a colorless to light yellow transparent viscous liquid, belongs to nonionic surfactants, with an active content of ≥99%, free alcohol content ≤0.5%, high purity and low impurities.
Due to the absence of easily hydrolyzable groups such as ester bonds and amide bonds in the molecular structure, the product maintains chemical stability over a wide pH range of 3~12, and its performance is not significantly affected in acidic, alkaline, or hard water environments. Its HLB value is about 18, cloud point >100°C, and it is highly soluble in water, making it a typical O/W emulsifier and efficient solubilizer.
| Parameter | Specification/Value | Parameter | Specification/Value |
|---|---|---|---|
| CAS Number | 31694-55-0 | Appearance | Colorless to light yellow transparent liquid |
| INCI Name | Glycereth-18 | Active Content | ≥99% |
| Molecular Formula | C₃H₅(OC₂H₄)n(OH)₃₋n, n≈18 | Average Molecular Weight | 800~900 |
| Ionic Type | Nonionic | HLB Value | About 18 |
| pH Value (1% Aqueous Solution) | 5.0~7.0 | Cloud Point | >100°C |
| Density (25°C) | 1.05~1.10 g/cm³ | Hydroxyl Value | 180~200 mgKOH/g |
| Kinematic Viscosity (40°C) | 100~200 mm²/s | Acid Value | ≤0.5 mgKOH/g |
| Surface Tension (1% Aqueous Solution) | 35~40 mN/m | Water Content | ≤0.5% |
| Free Alcohol Content | ≤0.5% | Refractive Index (25°C) | 1.455~1.465 |
| Chemical Stability | Stable within pH 3~12 | ||
| Water Solubility | Easily soluble in water | ||
This product has a wide range of applications; recommended uses are as follows: